Table of Contents
Next Section
Home

I.C. DEVELOP TOOLS NEEDED TO IMPLEMENT MODEL PROGRAMS

(a) First-Tier Functional Screening

(b) Second-Tier Functional Screening

(c) Design and Methodology For On-Road Evaluations of Driving Competence

IC2(a)i. Gross Impairments Screening (GRIMPS) Battery of General Physical and Mental Abilities

Equipment and Materials: Furniture (desk or table, and two chairs, including at least one straight-backed chair); 10-ft long tape measure (for rapid-pace walk); colored duct tape (to mark 10-foot path if space is dedicated for GRIMPS); stop watch (for timed tests); cardboard clock face with high contrast between the numerals, the clock hands, and their background (to be used in head/neck flexibility test); lap seat belts (for use in head/neck flexibility test); laminated 55-inch by 8.5-inch chart to be hand-held or wall-mounted (for measuring abnormalities in visual scanning patterns); pencil; and data forms (for Trail-Making tests, Motor-Free Visual Perception test, and data recording forms). If GRIMPS is performed in a public space, including office environments, senior centers, etc., movable partitions should be used to provide a private testing area, approximately 11-ft long x 8-in wide. A "GRIMPS Kit" including all materials except furniture and partitions has been developed, and is available for distribution to test administrators. The "Kit" comes in a 3-ring binder; the binder itself serves as test equipment for the alternating foot-tap measure. The cost of all materials included in the "GRIMPS Kit" is $40.00.

Data Recording and Test Scoring: Driver's performance on GRIMPS is typically recorded on the prepared data form (1 page) at the time of testing, retained as a (single page) hard copy record, and transferred to an electronic file after the protocol is completed. An example data form is presented on the following page. Alternately, performance data can be entered on a PC at the time of testing. When GRIMPS is administered in an agency setting as per a given jurisdiction's policy, absolute and/or normalized measures of performance may be provided to drivers with an explanation of resulting licensing or referral action (if any). Similarly, performance norms with (preliminary) cutoff scores will support recommendations for follow up actions (e.g., referral) by GRIMPS administrators in an Area Agency on Aging, health care facility, social service facility, or other private or community setting. Norms developed through field tests will be provided to States/Provinces and other interested parties, and will be updated on a regular basis as more data become available.

Test Procedures: A private testing environment must be established, by using a separate office or partitioning a suitable space in a larger room. An enclosed area approximately 11' long by 8' wide is recommended. An opening should be provided at one end of the testing area (door optional) and a table and two chairs should be situated near the opposite end of the testing area. (Note: It is anticipated that space requirements for GRIMPS tests can be met in a driver's own home).

The test protocol begins when the examiner greets the driver and positions him/her just outside the opening to the testing area to deliver instructions.

[ Maryland GRIMPS score sheet ]

This is the first test, which is a measure of lower limb mobility. The measuring tape is laid on the floor, pulled out to its full 10-ft length, and locked open at this length. The subject walks next to the measuring tape, turns at the end, and walks back to the start position. The total walking distance is 20 ft. Alternatively, the adhesive tape can be pre-applied on the floor to mark the 10-foot path, in settings where dedicated space is allocated for conducting GRIMPS. The examiner will say, "I want you to walk along side of this tape measure (tape line) to the end, turn around, and walk back here as quickly as you can." (Demonstrate) "If you use a cane or walker, you may use it if you feel more comfortable. I am going to time you. Go as fast as you feel safe and comfortable." "Ready, begin."

Start timing when the subject picks up his or her first foot. Stop timing when the last foot crosses the finish line. Record the total time to traverse the 10-ft path up and back with the stop watch.

Norms: Marottoli, Cooney, Wagner, Doucette, and Tinetti (1994)

 

Statistic	Entire cohort of persons age 72+ living in the New Haven Community	Subset of active drivers
n	1007	348
mean (in seconds)	9.635	7.97
standard deviation	5.11	3.43

Guralnik, Simonick, Ferrucci, et al. (1994):

• mean for all subjects age 71+ (n=5097): 5.0 seconds
• mean for all men age 71+ (n=1785): 4.4 seconds
• mean for all women age 71+ (n=3312): 5.3 seconds

Subjects who took longer than 7 seconds to complete the rapid-pace walk were twice as likely to experience adverse traffic events (traffic crash, violation, stopped by police) in the year following testing as subjects who completed the walk in 7 seconds or less [relative risk, 2.0, CI 1.0-3.8]) (Marottoli et al., 1994). The Guralnik study found that those taking longer to complete a battery of three lower extremity tests (rapid-pace walk, chair stands, and standing balance) were 4.2 to 4.9 times as likely to have disability at four years than those with the best scores; tests were also predictive of nursing home admissions and mortality rates.

This is a test of immediate memory. Direct the driver to sit in the straight-backed chair at the table. When driver is seated, the examiner sits across the table and delivers the instruction, "I'm going to say three, short words now as a memory test. Please repeat them back to me in the same order." The examiner verbally announces three short, common but unrelated words, which serve as a memory set (BED, APPLE, SHOE), then again asks the driver to repeat them back.

The examiner records the number of memory set elements accurately repeated. If the driver cannot repeat all three elements in the set, the examiner should announce it again, up to a maximum of six times. The examiner also records the number of times the memory set was announced. After this is completed, The examiner delivers the instruction, "I will ask you again later to remember these same three words and say them to me."

This is an alternative measure of lower limb mobility, as required of a driver to move his or her right foot from the gas pedal to the brake pedal. The driver sits in a chair for this test. The test administrator opens the 3-ring binder and places it on the floor with the 3 rings oriented crosswise in front of the participant, and located at a distance of 16 to 24 inches from the front edge of the chair. This should provide a separation between foot tap locations of approximately 12 inches. Following instructions, the driver will touch his or her right foot to the floor 5 times alternately on each side of the opened binder, moving from one side to the other on every tap. The total number of taps will be 10. The driver must make sure to lift the foot sufficiently high to clear the rings of the binder.

Instruct the driver, "Please place your right foot on the floor, next to the right side of this binder. Now move your left foot back out of the way, and move your right foot back and forth over the binder rings, alternately tapping each side of the floor next to the binder. Move your foot back and forth across the binder rings for a total of 10 taps, beginning when I tell you. I will time how quickly you can do this. [Test administrator demonstrates foot tap motion]. Ready? Go."

The examiner records the time to complete the foot tapping task with a stop watch.

Norms (right foot-tap time): Marottoli, Cooney, Wagner, Doucette, and Tinetti (1994):

 

Statistic	Entire Cohort Age 72+	Drivers Only Age 72+
	Right Foot Tap	Right Foot Tap
n	1055	352
mean	5.61 s	4.80 s
sd	2.48	1.56

The MVPT is an individually administered, multiple-choice test of visual perception. The only response required from the subject is that he or she point to whichever one of four alternatives is correct. The subject is not allowed to trace any figures. The examiner should encourage the subject to look at all four alternatives before making a final decision. The MVPT is not a timed test, and the subject should be given a reasonable amount of time (15 seconds) to make a selection. The examiner scores the subject's response by marking the appropriate space on the accompanying scoring sheet. The visual closure subtest measures the ability to identify incomplete figures when only fragments are presented (see example on following page). This subtest should take no more than 3 minutes to administer.

Instructions for practice items for visual closure subtest: Point to the four alternative figures, saying, "If we finished drawing these figures, which one would look just like this one?" Now point to the stimulus figure. After the subject responds, point to the correct alternative saying, "Yes (No), if we connected these lines, this one would look just like this." Point to the stimulus figure.

Instructions for items 22-32: Point to the four alternative figures, saying, "If we finished drawing these figures, which one would look just like this one?" Now point to the stimulus figure. No confirmation or explanation is given.

For GRIMPS application, the examiner records number of incorrect responses. The cut-point for passing vs failing will be established after pilot study data (from the Maryland MVA) are analyzed.

This is a test of upper limb mobility. The driver does this test while sitting in the chair.

Examiner asks the driver,"Please raise your right arm as high as you can over your head. You may put your arm down... Now please raise your left arm as high as you can over your head."

The examiner records whether or not driver could lift each arm above shoulder height. Drivers who can not reach above the height of their shoulders will "fail" this test.

The driver does this test while seated in the chair. It is a measure of the ability of a driver to turn and look over his/her shoulder to see to the sides and rear of the vehicle when changing lanes or merging. The examiner should ask the driver to buckle the seat belt that has been attached to the chair, and to tighten it. The examiner should prompt the driver to check again to make sure the belt is as tight as it can be without discomfort. This part of the procedure is to ensure that the driver remains positioned in the chair, with his or her lower back pressed against the seat back, in the same posture that he or she would assume when sitting in the driver's seat of a car. The examiner stands 10 feet behind the driver at a pre-marked location, and sets the clock hands to either 3:00 or 9:00 while the examinee is facing the opposite direction.

The examiner delivers the instruction, "Just as you would turn your head and upper body to look behind you to back your car or change lanes, please turn and read the time on the clock face that I am holding behind you."

The examiner records whether the driver can read the requested information. If the examinee can not turn far enough in one direction to read the clock, he or she should be asked to try turning the other way. The test is scored as pass (the driver can turn his or her head to read the clock) or fail (the driver does not have enough flexibility/mobility to perform this motion).

[ Motor-Free Visual Perception Test: Visual Closure Subtest (Example Item (The answer is A)) ]

Scanning Task

The scanning test is presented on a 55-in by 8.5-in laminated sheet that displays 10 common symbols. The symbols are arranged in 2 rows of 5 columns, as shown below.

The driver is seated 3 to 5 feet from the stimulus sheet, only after the following instructions have been delivered. The examiner states, "without moving your head, scan the poster and report to me the symbols you see. If you do not know what a particular symbol is called, describe what it looks like." The examiner notes the order in which the driver reports the symbols.

A normal scan pattern of a cognitively-intact individual may be any of three: (1) rectilinear (left to right/top to bottom); (2) clockwise; or (3) counterclockwise. Subjects with impaired visual scanning capabilities demonstrate disorganized, random, and/or abbreviated or truncated strategies (frequently missing items on one side of the board). Those with hemi-neglect often show an asymmetrical pattern, initiating visual search from the right side rather than the left and confining all search efforts to the right side. Also, whereas subjects with normal visual attention never overlook or repeat a stimulus on the test, those with inattention may commit both of these errors. Scan patterns for GRIMPS will be scored as one of three categories:

1. Normal: Clockwise, counter-clockwise, by rows, by columns.
2. Erratic: All symbols identified, but in haphazard order.
3. Neglect: Two or more shapes not identified at all.

This is a paper-and-pencil test of general cognitive function. Specific functional capabilities targeted by this assessment tool include: visual search and sequencing (Part A); and information speed and attention switching (Part B). Both parts require effective psychomotor coordination. Part A involves connecting, in order, 25 encircled numbers randomly arranged on a page. (For this application, an abbreviated Trails A test is used, containing only 8 numbers, to reduce the amount of time allotted for GRIMPS). Part B includes both numbers (1-13) and letters (A-L), and requires connecting the two in alternating order (1 to A, to 2, to B, etc.). The score on either test is the overall time (seconds) to complete the connections. The last item completed at each 30-second interval is also recorded by the examiner. Mistakes are pointed out by the test administrator and are corrected as they occur; their effect is to increase the overall time required.

The instruction delivered by the examiner is, "Now I will give you paper and pencil. On the paper are the numbers 1 through 8, scattered across the page. Starting with 1, draw lines to connect each number to the next higher number. I will time how fast you can do this. Ready? Go." The examiner records time-to-complete.

The examiner then states, "On this sheet of paper the numbers 1 through 13 and the letters A through L are mixed up in the same way. This time, start with 1, then draw a line to A, then draw a line to 2, then to B, then 3-C, 4-D, and so on, alternating back and forth between numbers and letters until you finish with the number 13. Again, I will time how fast you can do this. Ready? Go." The examiner records the last item completed at each 30-second interval, plus total time-to-complete. The Trails B test sheet is shown on the following page.

Norms for Trails B

Stutts, Stewart, and Martell (1998): The means by age group for time to completion (in seconds) for Trails B from the study were 78.8, 85.8, 93.7, and 106 seconds, for age groups 65-69, 70-74, 75-79, and 80+ respectively. Stutts et al. (1998) state that average completion times for the two Trail-Making Tests were below (i.e., better than) published age norms of Heaton et al., 1991 and Davies, 1968, and suggest a relatively healthy and/or well educated sample.

Richardson and Marottoli (1996): Age and education-specific normative data were provided for 101 independently living active drivers, free from neurologic and psychiatric disease. Mean time to complete (and standard deviations) were as follows:

• age 76-80/education<12 years (n=26) = 197.17 seconds (71.03);
• age 76-80/education>12 years (n=24) = 119.17 seconds (33.47);
• age 81-91/education<12 years (n=18) = 195.47 seconds (69.70);
• age 81-91/education > 12 (n=33) = 137 seconds (55.93).

Also in this paper were means and standard deviations interpolated from conversion tables provided by Heaton, Grant, and Matthews (1991):

• age 75-80/6-8 years of education=184.5 (92.5);
• age 75-80/9-11 years of education = 157.5 (78.5);
• age 75-80/education > 12 years of education = 122.5 (55.5).

Davies (1968):

Age 60-69 (n=90)

90th percentile = 64
75th percentile = 89
50th percentile=119
25th percentile=172
10th percentile = 282

Age 70-79 (n=90)

90th percentile =79
75th percentile =132
50th percentile=196
25th percentile=292
10th percentile = 450

[ Trail-Making Test, Part B ]

This is a test of working memory. The examiner asks, "Please tell me again the three words you repeated earlier." Examiner records the number of words recalled correctly, and announces that the test is completed.

If GRIMPS is administered in a motor vehicle agency setting, drivers' visual capability will be tested using the established protocol for the jurisdiction. Typically, only a static acuity measure and a gross measure of the horizontal peripheral field size will be obtained.

For other settings, it is recommended that the GRIMPS administrators add measures of standard and low contrast acuity to the other tests described above. Stimuli for each test are presented on 5.5 in by 5.5 in test card that serves as a "wall chart" when viewed from a distance of 5 ft. (Note: the distance has been adjusted for GRIMPS administration). The chart is printed on folded stock so that it is also self-standing. The charts are obtained from the AARP (1992) "Older Driver Skill Assessment and Resource Guide: Creating Mobility Choices." Permission to use these charts has been granted from AARP.

Place Chart 1 (the high contrast side) on a convenient surface in a brightly lit location 5 feet from the test participant, at eye level. The correct letters are printed below. As the person reads each line, circle only WRONG answers.

Ask the participant: "Please tell me the letters printed on the top line."

Then ask the participant to read each successive line. The smallest line of letters without any errors is the acuity score. Record both the line number and the corresponding acuity score.

Now turn the chart around so that Chart 2 (the low contrast side) is facing the participant (the chart should still be placed at eye level in a brightly lit location, 5 feet from the test participant).

Tell the participant "This chart measures your ability to see low contrast objects. Low contrast objects are harder to see than high contrast objects. You need to be able to see low contrast objects when you drive, like worn or faded lane lines, curbs, medians, pedestrians, and other vehicles. These things are harder to see in poor visibility conditions like fog, or at dusk and dawn."

Ask the participant: "Please tell me the letters printed on the top line."

The correct letters are printed below. As the person reads each line, circle only WRONG answers. Then ask the participant to read each successive line, and record the participant's responses. The smallest line of letters without any errors is the acuity score. Record both the line number and the corresponding acuity score. Also record the difference between the line number obtained on Chart 1 and Chart 2.

NOTE: Scores for the low contrast chart will probably be 1 or 2 points lower than for the high contrast chart. The greater the difference between the two scores, the greater is the caution the participant must take when driving in low light conditions. A participant may be advised to limit night driving, and should see his or her eye care specialist to rule out eye diseases such as cataracts.

 

Chart 1: High Contrast			Chart 2: Low Contrast
Line	Acuity	Letters	Line	Acuity	Letters
1	20/100	O R S	1	20/100	R H K
2	20/80	Z H N	2	20/80	H N V
3	20/60	H S R	3	20/60	N K S
4	20/50	S Z K	4	20/50	Z R H
5	20/40	V R N	5	20/40	K V S
6	20/30	Z S H	6	20/30	R Z N

[ High contrast acuity chart (top) and low contrast acuity chart (bottom). ]

(Reprinted with permission from AARP's Older Driver Skill Assessment and Resource Guide: Creating Mobility Choices)

IC2(a)ii. Vision Screens
(commercially available (1))

Wall Charts/Cards:

Pelli-Robson Test of Static Contrast Sensitivity
Clement Clarke, Inc., 3128 East 17th Avenue, Columbus, OH 43219, (800) 848-8923.

Chart measures 25 x 34 in, and comes with scoring pad (100 sheets) and instructions for use.

Pelli, Robson, and Wilkins (1988) designed a 48-letter test of contrast sensitivity at one spatial frequency. The contrast between letters and background decreases as one moves down and toward the right of wall-mounted chart, viewed at distance of 1 meter (about 40 inches) under normal room illumination (white area approximately 85 cd/m²). The letters from left to right and from top to bottom progressively fade out, as if they must be read in thicker and thicker fog. Letters (in groups of 3) range from 90 percent contrast (upper left) to 0.5 percent contrast (lower right). Drivers should be made to guess, even when they believe that the letters are invisible. The examiner should allow several seconds for the faintest letters to appear, but don't let the driver give up until he or she has guessed incorrectly 2 of the 3 letters in a triplet, as the reliability of the results depends on this. The driver's sensitivity is indicated by the faintest triplet for which 2 of the 3 letters are named correctly. The log contrast sensitivity for this triplet is given by the number on the scoring pad nearest to the triplet. The instructions indicate that three measurements should be taken: left eye, right, eye, and both eyes together. If all three measures are taken, test time is approximately 8 minutes. Binocular log contrast sensitivity is normally 0.15 higher than monocular.

Vistech Consultants Vision Contrast Test System (VCTS 6500)

Vistech Consultants, Inc., 4162 Little York Road, Dayton, OH 45414-2566, (937) 454-1399.

[Note: First Generation of tests is available from Vistech; Second generation/revised charts (exclusive arrangement with Dr. Ginsburg) are available through Stereo Optical.]

First Generation: includes chart, instruction manual, evaluation forms, light meter, laminated instruction sheet and answer key.

VCTS 6500 - Far distance wall chart; measures 27 in x 37 in; 10 ft viewing distance.

VCTS 6000 - Portable near vision chart; measures 5 in x 7 in; 18 in viewing distance.

VCTS 6500 Chart contains 5 rows of sine wave gratings (1.5, 3.0, 6.0, 12, and 18 cycles per degree) and 9 columns of "patches" containing bars that vary in contrast. The bars are either oriented straight up and down, slanted to the right, or slanted to the left. The driver starts at the first row, and "reads" across, telling the examiner in which of the three directions the bars are oriented. The contrast decreases in each row from left to right. The highest numbered patch that can be correctly seen in each row of the chart is the observer's contrast sensitivity for that spatial frequency. Observer views chart from a 10 ft distance, under normal room lighting (30-70 footlamberts).

Smith-Kettlewell Institute Low Luminance (SKILL) Card

The Smith-Kettlewell Eye Research Institute, 2232 Webster Street, San Francisco, CA 94115, (415) 561-1620.

Available from the Smith-Kettlewell Institute, who requests a donation for the chart.

This is a test for assessing visual function under the conditions that "stress" the visual system; the combination of low contrast and low light level. It is designed to measure spatial vision under conditions of reduced contrast and luminance using normal office lighting. Its developers state that it is sensitive to alterations in visual function due to optic neuritis, glaucoma, and age-related maculopathy, and that it is closely correlated with reading performance in patients with early age related maculopathy and with driving performance in the elderly.

This letter chart is viewed at a distance of 40 cm (16 in). From the top of the chart to the bottom, each line of letters is smaller than the line preceding it. One of the SKILL Card charts shows black letters on a white background (high-contrast letters); the other card shows black letters on a dark gray background (low contrast letters on a low-luminance background). Guessing is encouraged. Instructions for use and scoring are included, as well as score sheets and age norms. The SKILL score is the acuity loss (number of letters) between the light and dark sides.

Vision Screening Devices:

Vistech Consultants Multivision Contrast Tester (MCT 8000)

Vistech Consultants, Inc., 4162 Little York Road, Dayton, OH 45414-2566, (937) 454-1399.

Multivision Contrast Tester measures near and far distance contrast sensitivity, three types of glare (central, peripheral, and radial), near and distance acuity.

The Cataract Functional Disability Test, performed with the MCT 8000 documents the degree of functional disability a patient is experiencing as a result of a cataract.

OPTEC 1000 DMV

Stereo Optical Company, 3539 North Kenton Avenue, Chicago, IL 60641 1-800-334-9500, 312-777-2869.

Slide packages vary according to requests from various state DMVs; Optec can design and develop new tests as the need arises.

Slides may include 4 tests: Snellen letter and number acuity, color perception, stereo depth perception, traffic sign recognition, muscle balance phoria. A set of 2 contrast sensitivity slides (Vistech consultants sine wave gratings) is also available. The Optec 1000 DMV can also accomplish perimeter testing (nasal and temporal at 55, 70, and 85 degrees) and night vision testing.

Static Acuity

Standard Wall Charts (Snellen Letter Chart and Sloane Letter Chart):

Snellen "E" Charts

(Available from Prevent Blindness America, 500 E. Remington Road, Schaumburg, IL 60173; 1-800-331-2020).

20-ft. distance: Tumbling "E" symbols on one side, other letters on reverse. Printed on a durable, tear-resistant latex sheet, with eyelets for easy hanging. Chart comes with practice "E" card and Guide to Testing Distance Visual Acuity. Measures 9 in x 23in.

10-ft. distance: Smaller chart for shorter distance. Other specifications same as above. Measures 9 in x 18 in.

Sloan Low Vision Letter Chart for 6 Meters (20 ft)

(Available from Good-Lite Co. 1540 Havannah Avenue, Forrest Part, IL 60130; 708-366-3860).

Two-sided chart (10 in x 18 in ) where one side contains 4 rows of letters from 20/200 to 20/100 acuity, and the other side contains 8 rows of letters from 20/100 to 20/20. Two test charts per set.

ETDRS (Early Treatment Diabetic Retinopathy Study) Chart:

(Available from Prevent Blindness America, 500 E. Remington Road, Schaumburg, IL 60173 1-800-331-2020).

ETDRS Distance Chart: This durable eye chart utilizes all 10 Sloan letters (C, D, H, K, N, O, R, S, V and Z) to test vision at 10 feet. Each line consists of five optotypes, standardizing the number of letters that must be correctly identified to pass any line (three out of five). Three sets of letters on the lower lines can help prevent memorization. Made of durable plastic, with hole for hanging. 18 in x 18 in; folds to 9 in x 18 in. (Shipped directly from the manufacturer.)

ETDRS Near Chart: This innovative new chart, developed especially for Prevent Blindness America, includes an occluder on a 16-inch cord for testing near vision. Printed on both sides for discouraging memorization and screening each eye with a different but equally difficult test. Five optotypes per line standardizes passing at three out of five on each line. Made of durable plastic; utilizes all 10 Sloan letters (C, D, H, K, N, O, R, S, V and Z). Measures

9 in x 7 in.

IC2(a)iii. Road Sign/Knowledge Test

According to information presented by Janke and Hersch (1997), only four U.S. jurisdictions and two Canadian provinces require an age-based knowledge test for driver license renewal. This includes the District of Columbia, Illinois, Indiana, New Hampshire, Alberta, and Ontario. Six other jurisdictions require knowledge tests for all license renewals (regardless of age). This includes California, Hawaii, Kansas, Louisiana, Michigan, and Utah). Janke and Hersch (1997) analyzed test results for 1,501 California driver license applicants ages 65 and older who failed to complete the license renewal process during their initial visit to the DMV. Some drivers fail the knowledge test several times, despite having an opportunity to review the material in the Driver Handbook between tests. While 47.4 percent passed it on the first attempt, the failure rate for older drivers renewing their licenses is higher than that for the population as a whole.

In Oregon, if a driver is referred to the DMV for reexamination, he or she is offered an appointment with a Driver Improvement Counselor, who is "an experienced former driver examiner who has received special training and whose role is to advise, recommend, critique, and persuade, rather than to merely test the driver" (Janke, 1994). One component is an oral knowledge test consisting of seven questions. Six are prescribed and one may be chosen from the State's regular oral test. The six prescribed questions are:

(1) You are preparing to make a left turn from a two-way street. Your car should be in what position?
(2) At an intersection where there are no stop signs or traffic lights to control traffic, you must yield to the car on which side of you?
(3) You are coming toward an intersection with a two-way street. In which direction should you look first?
(4) You are in a "left turn only" lane and you want to go straight ahead. What should you do?
(5) Tell the correct way to change lanes.
(6) Tell what it means when a school bus is stopped and its red lights are flashing.

Several researchers have evaluated the effectiveness of traffic sign knowledge tests and rules of the road tests in predicting crashes or impaired driving performance. In a study of 3,238 drivers ages 65 and older who applied for renewal of North Carolina driver's license, Stutts, Stewart, and Martell (1996) found that performance on the knowledge test declined significantly as a function of increasing age (time to complete test increased with increasing age). The correlation between knowledge test score and number of crashes was significant. This test required the driver to identify and explain the meaning of 12 traffic signs based on their color and shape (e.g., yellow diamond with + would be identified as a warning sign for a crossroad ahead). The signs were displayed six at a time in the viewing equipment used for vision testing. The test is not normally timed for license renewal, however, for the research, examiners recorded how long (in seconds) it took license applicants to complete the test. Applicants were not told they were being timed; the number of errors remained the only criteria for passing or failing test. Three or more errors automatically dismisses a license applicant.

Tarawneh, McCoy, Bishu, and Ballard (1993) found that the driving knowledge test score was significantly correlated with driving performance (correlation coefficient =0.27, p=0.0053). Better performance on the knowledge test was associated with better on-road driving performance. The knowledge test was a 50-question, multiple choice test designed to determine the driving knowledge pertinent to the types of crashes in which older drivers in Nebraska were over-involved.

Questions pinpointed contributing circumstances (failure to yield, disregard signal, improper turn signal, improper turn, following too close, and improper lane change) and crash type (right angle, rear end, side swipe, head on, left turn, other turn, right turn, and pedestrian). The percentage of the questions answered quickly was used as the measure of driving knowledge.

In another study, Cushman (1992) found that the group of subjects who failed an on-road driving exam had significantly lower mean scores on the written (multiple choice) knowledge test and the road sign identification test compared to the group of subjects who passed the on-road driving exam. The road (driving) knowledge test was a multiple-choice, paper-and-pencil test consisting of 21 questions assessing knowledge of rules of the road. It additionally required subjects to identify and describe the meaning of 16 road signs (what the required driver action was).

Hunt, Morris, Edwards, and Wilson (1993) employed a traffic sign recognition test that required the identification of the following four standard symbols: traffic merging, no right turn, no left turn, and no U turn. These symbol signs were chosen because they are frequently encountered in everyday driving situations. Subjects were asked to explain the meaning of each symbol. Each item was scored individually to determine if one type of sign posed greater difficulty than the others. All five subjects with mild dementia who failed the road test also performed poorly on the pre-driving traffic sign recognition test. The correlation between the pass/fail outcome on the road test and performance on the Traffic Sign Recognition test was significant at the p<.0002 level. The authors noted that visual form detection may be impaired in mild senile dementia of the Alzheimer type (SDAT), while visual acuity remains intact; this may contribute to the difficulty some subjects experienced with sign recognition, since the signs were symbols (form) rather than letters (acuity).

In a research study of 102 older drivers referred to the DMV for a reexam and 33 paid volunteers, the correlation between knowledge test errors (standard California renewal knowledge test) and weighted errors on the road test was significant for the combined referral and volunteer group and for the referral group only (Janke and Eberhard, 1998; Janke and Hersch, 1997). The Driver's Examination on California Vehicle Code and Safe Driving Practices contains 18 multiple choice questions, each with 4 choices. A renewal applicant must score at least 15 (3 errors or less) to pass the test. There are 5 different versions of the test, with questions developed from information presented in the 1997 California Driver Handbook. One or two questions relate to the meaning of signs and pavement markings depicted on the test form, others ask about the legal BAC limit, visual scanning practices, the meaning of signals, what to do if involved in a crash, etc.

Janke and Eberhard (1998) and Janke and Hersch (1997) also reported on a supplementary test of traffic sign knowledge and perception. This two-part written traffic-sign test presented pictures of traffic signs and asked whether it meant that the driver should perform a certain action (e.g., "watch for hazards"). A second part presented several traffic sign shapes embedded in complex abstract drawings, and subjects were to indicate the number of sign shapes of a particular type hidden in the drawing. Using the sample of subjects mentioned above, sign test errors correlated significantly with weighted errors on the road test for the combined referral and volunteer group, but not for the referral group only.

Janke and Hersch employed another traffic sign recognition test in a study of 101 licensed drivers ages 72 to 90. This was a paper-and-pencil test consisting of 12 factually oriented questions requiring a subject to check an alternative corresponding to the meaning of each pictured sign, and one judgmentally oriented question, where an intersection displays a "no left turn" and two "do not enter" signs on the through path, and the subject must check the alternative corresponding to what they could do (turn right). The correlation between traffic sign errors and weighted error score on the drive test was not significant. Janke and Hersch (1997) recommend that jurisdictions employ knowledge testing for license renewal. They stated that an adequate knowledge test given to all renewal applicants may be sufficient to screen out most cases of cognitive impairment and that it should be possible to modify present tests to make them not only tests of crystallized knowledge, but dementia screens. For example, diagrams of traffic situations could be incorporated in the tests in which drivers would be required to state what they should do if they were driving Car A, and then what they should do if they were driving Car B. The switching of attention and point of view required in such a task might prove to be especially difficult for a person with cognitive impairment.

A test such as that described above is given in Pennsylvania to drivers who have been convicted of violations of the PA Vehicle Code resulting in six or more points. Part of this Special Point Exam tests drivers' judgment about safe versus unsafe driving decisions, and accounts for two-thirds of the total score. The crash situations in the study guide and on the test are taken from reports of real crashes. In each crash situation there are a number of diagrams that show traffic conditions, vehicle movements, and traffic signs and signals in the crash area. Examinees are required to integrate all of this information to respond correctly. A description of what happened is under each diagram. An example of this kind of test question is shown on the following pages.

Conclusions/Preliminary Recommendations:

Performance on simple tests of traffic sign recognition and rules of the road has been shown to correlate significantly with poor driving performance and also with cognitive impairment. More complex test questions requiring drivers to visualize multiple perspectives, project their own and/or other vehicles' movements, or integrate a number of traffic situational factors show promise as protocols tailored to detect cognitive impairment.

References:

• Cushman (1992)

• Hunt, Morris, Edwards, and Wilson (1993)

• Janke and Eberhard (1998)

• Janke and Hersch (1997)

• PennDOT Special Point Examination Driver's Handbook

• Stutts, Stewart, and Martell (1996)

• Tarawneh, McCoy, Bishu, and Ballard (1993)

[ PA SPE (1) (2) ]

IC2(a)iv. Supplemental Tests Specialized for Attentional and Informational Processing Skills

Visual Attention (Selective Attention/Divided Attention)

Visual Attention Analyzer, Model 2000 (Useful Field of View)

Visual Resources, Inc., 333 West Wacker Drive, Suite 700, Chicago, IL 60606; phone: (773) 248-0883; fax: (773) 248-0885; email: kristi@ufov.com; contact: Kristi Berg.

A model 2000 Vision Attention Analyzer is used to measure the detection, localization and identification of suprathreshold targets in complex displays, and has been shown to be predictive of the performance of daily activities such as driving a car. The size of the UFOV is determined by manipulating three variables: target presentation duration, the competing attentional demands of the central and peripheral task, and the salience of the peripheral target. Three subtests provide a measure of the percentage reduction of a maximum 35 degree radius field. During the first subtest (which measures processing speed capability and vigilance), a test participant is required to identify a centrally located object which varies in duration, by pressing an icon of a truck or a car (whichever was presented) on the touch-screen display after the target is presented. The second subtest (which measures divided attention capabilities) requires the same identification, in addition to locating a simultaneously presented peripheral target of varying eccentricity. A third subtest (which measures selective attention capabilities) requires the same two responses required for subtests 1 and 2; for this subtest, the peripheral target is embedded in distractors. The composite measure of UFOV reduction is recorded as a percentage ranging from 0 to 90 percent, and the basis for the loss can be determined by considering the percentages of loss on the three subtests.

The Visual Attention Analyzer is currently available in several models and options. All are fully automated. UFOV testing is also available on disk through Visual Resources, Inc., and The Psychological Corporation.

Auto-Trails

Frank Schieber, University of South Dakota, 414 E. Clark Street, Psychology Department, Vermillion, SD 57069. Phone: (605) 677-5295; Fax: (605) 677-6604.

This procedure is a modified and automated version of Reitan's (1958) Trail Making Test (Part A). It presently runs in DOS mode, although it is being upgraded for a Windows environment. The software may be obtained for free from Dr. Schieber; however, the user must supply a touch screen and interface card. In this test, 14 numbers are presented on a computer monitor. They are arranged randomly against the still (static) background of a traffic scene as observed by the driver through the windshield. The subject must touch the numbers (touch screen display) in ascending order as rapidly and accurately as possible, consistent with the clinical "Trails" protocol. Timing is done by the computer.

Dynamic Trails Test [DynaTrails]

The Scientex Corporation; 1722 Sumneytown Pike, P.O. Box 1367; Kulpsville, PA 19443

Phone: (215) 412-4912; Fax: (215) 412-4911; e-mail: 75142.515@compuserve.com

Scientex has developed software to present a derivative of the Trails B procedure using a computer touch screen. A moving driving scene, stored on the hard drive as an MPEG file, is presented in the background. Test stimuli (numbers and letters) are overlaid on the driving scene. A data file of the subject's performance is generated which records the following data: the time after start at which each number and letter stimulus is pressed (including error responses); the exact coordinates on the screen where each response was made; and subject identifying information as entered on a set-up screen by the experimenter/test administrator. This is a Windows-based application.

This software product may be made available at cost, but with restrictions on copying or redistributing it, to qualified researchers and motor vehicle agency officials. For more information contact Scientex at the location above.

Channel Capacity (Information Processing)

WayPoint

WayPoint Research, Inc., 538 Burlington Road, Suite B, Atlanta, GA 30307, (404) 982-0011.

WayPoint is a brief, paper-and-pencil test, where subjects connect alternating numbers and letters in sequence. The test was developed to identify high-risk drivers (truck drivers, bus operators, etc).

Six exercises are presented in pamphlet form. The first 4 exercises contain 8 numbers and 7 letters which are to be connected in alternating number-letter order by means of a continuous pencil line; the last two exercises contain 5 numbers and 4 letters to be connected in the same way. Some exercises have small pictures used as irrelevant distractors. Subjects are instructed to keep going if they make a mistake. Performance on each exercise is timed with a stopwatch.

WayPoint can be administered one-on-one or in a group. It uses a (proprietary) Windows-based scoring program to assess crash risk (high or low), and a narrative about the person's strengths and weaknesses. The scoring system calculates channel capacity or information processing rate, accuracy, focus, vigilance (sustained attention), and search (the ability to find details in a visually noisy field). Based on these 5 interacting factors, a driver falls into one of 60 different categories. Associated with each category is a driving style and collision risk factor, which is a 5-point scale that expresses the likelihood of both "preventable" and "non-preventable" collisions.

IC2(b)i. Clinical Assessment of Dementia

Mini-Mental Status Examination

Summary

The MMSE is an 11-item (30 point) screening instrument for dementia (Folstein, Folstein, and McHugh, 1975) that contains test items in 6 general cognitive domains: orientation (items 1 and 2); registration, or learning and remembering new information (item 3), attention/calculation (item 4a: spelling "world" backwards or item 4b: counting backwards by 7 from 100), recall (item 5), language (items 6-10), and visuospatial perception/praxis (item 11: copying a figure of 2 intersecting pentagons). It requires approximately 10 minutes to administer. The 11 items are progressive and are to be asked in the order presented on the following page.

When given to 69 patients, the test was able to separate the three following diagnostic groups.

• Dementia: n=29, mean age = 80.8, mean MMSE score = 9.6, sd=5.8, range = 0-22

• Depression with cognitive impairment: n=10, mean age = 74.5, mean MMSE score = 19.0, sd = 6.6, range = 9-27

• Depression: n=30, mean age = 49.8, mean MMSE score = 25.1, sd= 5.4, range = 8-30.

For 63 normal elderly persons with an average age of 73.9 years, the mean MMSE score was 27.6, (sd=1.7, range = 24-30). Standardization of the test by administration to 63 normal elderly subjects and 137 patients indicated that the score of 20 or less was found essentially only in patients with dementia, delirium, schizophrenia or affective disorder, and not in normal elderly people or in patients with a primary diagnosis of neurosis and personality disorder.

The MMSE has been used extensively in older driver research studies, as summarized below.

In a study of 283 community-dwelling individuals ages 72 to 92 (mean age = 77.8), Marottoli, Cooney, Wagner, Doucette, and Tinetti (1994) found that persons with borderline cognitive impairment (MMSE score of 23-25) were more likely to have adverse events (traffic crash, violation, or stopped by police) in the year following examination than those with higher or lower scores (relative risk = 2.0, 95% CI = 1.1-3.7). The authors examined the components of the MMSE individually and by cognitive domain (orientation, memory, attention, language, and visuospatial ability), and found that the item most closely associated with adverse events was impaired design copying [24% of persons who could not correctly copy the intersecting pentagons had events compared with 8% of those who could (relative risk = 3.0, CI = 1.6-5.6)].

Johansson (1997) conducted a matched-pair, case-control study, with close (1 year) age matching in Sweden. The case subjects included 37 drivers age 65 and older (mean age = 75.5) with temporarily-suspended licenses due to crashes (23 drivers) or other moving violations (14 drivers). The control subjects included 37 drivers age 65 and older with no license suspensions. The case subjects (suspensions + crashes) had significantly lower MMSE scores (p=.019), lower immediate memory task performance (p=.010), and poorer performance on the cube copying task (p=.010) compared to matched controls.

[ Mini-Mental Status Exam ]

In a study of 101 licensed drivers (39 females and 62 males) ages 72 to 90 (mean age = 78.3), MMSE correct responses were not significantly correlated with road test weighted errors. However, MMSE correct responses did significantly correlate with concentration errors on the road test (r=0.09, p=0.359). MMSE "error areas," the number of cognitive domains represented on the MMSE on which at least one error was made, correlated 0.27 (p=0.006) with road test weighted errors and 0.29 (p=0.003) with concentration errors (Janke and Hersch, 1997).

In a study of 30 licensed drivers ages 61 to 89 (mean = 72.2), the correlation between MMSE score and in-traffic score was 0.72, and was significant at the p<.01 level (Odenheimer, Beaudet, Jette, Albert, Grande, and Minaker, 1994). Subjects were recruited by word-of-mouth from studies of normal aging (n=17), medical and dementia clinics (n=9), and from the community (n=4). Adjusting for age resulted in no change in the correlation. Although there was a strong correlation between the MMSE and driving performance, the MMSE alone was deemed inadequate to predict driving performance. The MMSE scores of the four subjects who failed the road test were 4, 16, 21, and 24. Of the subjects who passed the road test, the lowest MMSE score was 14.

Tarawneh, McCoy, Bishu, and Ballard (1993) studied 105 drivers licensed in Nebraska, who were between the ages of 65 and 88 (mean age = 71.4). In this study, the MMSE showed a significant correlation to performance on an on-road driving test (correlation = 0.24, p<0.01).

A consensus statement was generated by 22 researchers who met in Borlange Sweden, aimed at providing advice to primary care physicians concerning the assessment of cognitive status in relation to driving (Lundberg, Johansson, Ball, Bjerre, Blomqvist, Braekhus, Brouwer, Blysma, Carr, Englund, Friedland, Hakamies-Blomqvist, Klemetz, O'Neill, Odenheimer, Rizzo, Schelin, Seideman, Tallman, Viitanen, Waller, and Winblad, 1997). Although consensus could not be reached concerning the issue of a cut-off score on the MMSE, it was determined by the majority (with some reservation) that some cut-off levels can be cautiously proposed in the context of decisions concerning future driving.

• Cut-off scores must be considered as being relative, forming a small part of the basis of making decisions about driving, and secondary to a clinical evaluation.

• MMSE scores 10, accompanied by a diagnosis of dementia, indicates a sufficiently low level of cognitive functioning to justify recommending immediate cessation of driving.

• MMSE scores of 11-17, accompanied by a diagnosis of dementia, suggests severe cognitive impairment; the patient should be referred for specialized assessment unless the clinician feels that it is unnecessary.

• MMSE scores of 18-23 indicates mild impairment; decisions concerning possible assessment should be based on the functional level of the patient. If the functional level is stable, then a periodic follow-up is recommended. If functional deterioration is present, then specialized assessment is recommended.

• For patients without diagnosis of dementia, scores of 17 or less and scores of 18-23 with accompanying signs of functional deterioration should be indications for specialized assessment.

• Some participants could not accept this suggested use for the following reasons:

• Risk of designating false positives; low scores are related to illiteracy, aphasia, depression, and resistive behavior; may not correctly assess mental status of patient.

• MMSE does not assess poor judgment and impulse control; persons with scores above the cut-off may be inappropriately viewed as safe drivers.

• Use may be wasteful adding nothing more to evaluation of competence than clinical observation of general cognitive functioning.

References:

• Folstein, Folstein, and McHugh (1975)

• Lundberg, Johansson, Ball, Bjerre, Blomqvist, Braekhus, Brouwer, Blysma, Carr, Englund, Friedland, Hakamies-Blomqvist, Klemetz, O'Neill, Odenheimer, Rizzo, Schelin, Seideman, Tallman, Viitanen, Waller, and Winblad (1997)

• Marottoli, Cooney, Wagner, Doucette, and Tinetti (1994)

• Johansson (1997)

• Janke and Hersch (1997)

• Odenheimer, Beaudet, Jette, Albert, Grande, and Minaker (1994)

• Tarawneh, McCoy, Bishu, and Ballard (1993)

• Drachman and Swearer (1995)

Mattis Organic Mental Syndrome Screening Examination (MOMSSE)

Summary:

The MOMSSE is a brief mental status examination (Mattis, 1976) consisting of items testing:

• General fund of information (e.g., How many weeks are in a year?).

• Verbal Abstraction (e.g., How are a poem and statue alike?).

• Attention (forward and backward digit span).

• Memory (orientation, verbal memory, reproduction of design from memory).

• Language (e.g., test for objects, body parts, double and triple commands, reading silently and aloud).

• Construction (draw a clock, cube copying).

It is comprised of a sample of several WAIS subtests, a Benton geometric figure, and some items from the Eisenson Test of Aphasia. It requires 15 to 20 minutes to administer.

Owsley, Ball, Sloane, Roenker, and Bruni (1991) employed the MOMSSE in a study of 53 drivers ages 57 to 83 (mean age = 70). Each of the 14 subtests was scored from 0 (normal) to 2 (impaired), and an overall composite score was calculated by adding subtest scores. Composite scores ranged from 0 to 28 (0 = excellent mental status; 28 = severe dementia). Individuals with high MOMSSE scores (n=8) experienced 3.8 times more crashes on average than those with MOMSSE scores less than 10 (n=45). For intersection crashes only, subjects with MOMSSE scores greater than 10 (n=8) had a total of 9 intersection crashes, and those with scores less than 10 (n=39) had only 7 intersection crashes between them. On the basis of the number of subjects in each group, individuals with higher MOMSSE scores had 6.3 times more intersection crashes than those with lower scores. Mental Status (score on MOMSSE) was found to be significantly related to number of crashes (r=.36). When crashes were categorized by type, most were found to be intersection problems. MOMSSE scores were found to be better predictors of intersection crashes than crashes in general (r=.41). MOMSSE and UFOV together predicted 29 percent of the variance in intersection crashes, and 20 percent of the variance in crashes in general.

In a study of 294 subjects ages 56 to 90 (mean age = 71 years), Ball, Owsley, Sloane, Roenker, and Bruni (1993) found a significant correlation between MOMSSE score and crash frequency (r=.34, p<.01). Data were tested with the LISREL VII structural modeling program to evaluate independent variables in terms of whether they directly influence the dependent variable (crashes), or if they operate indirectly through other variables. In this study, UFOV and mental status were the only variables that had a direct effect on the crash-frequency variance. Mental status was found to have a small, but significant direct effect on crash frequency, and a larger indirect effect on crash frequency through UFOV. Together, UFOV and mental status (MOMSSE) account for 28 percent of the variance in crash frequency. Mental status had sensitivity (.61) and specificity (.62) values that were "markedly" less than those for UFOV (.89) and (.81), respectively.

References:

• Ball, Owsley, Sloane, Roenker, and Bruni (1993)

• Mattis (1976)

• Owsley, Ball, Sloane, Roenker, and Bruni (1991)

Summary:

Originally a 26-item test (Orientation-Memory-Concentration) of cognitive impairment, it was shortened to a 6-item test, and has been shown to reliably discriminate among mild, moderate, and severe cognitive deficits. It is also easily administered by a nonphysician. The 6-item test predicted the scores on the 26-item validated mental status questionnaire in two patient groups in a skilled nursing home (n=322), patients in a health-related facility (n=42 and n=170), and in a senior citizen center (n=52). There was a positive correlation between scores on the 6-item test and plaque counts obtained from the cerebral cortex of 38 subjects at autopsy (Katzman, Brown, Fuld, Peck, Schechter, and Schimmel, 1983).

This test requires identification of current year and month, identifying time within one hour, counting backwards from 20 to 1, saying months in reverse order, and repeating a name and address that the test administrator has told the subject just before asking the current time. Weighted scores on the test range from 0 (no errors) to 28 (maximum errors). Scores of 0-8 indicate normal or minimal cognitive impairment; 9-19 moderate impairment; and 20 and above severe impairment.

Item Max Error Score Weight Weighted Score

1 What year is it now? 1 _____ x 4 _____

2 What month is it now? 1 _____ x 3 _____

Memory phrase:

Repeat this phrase after me: John Brown, 42 Market Street, Chicago

3 About what time is it? 1 _____ x 3 _____

(within 1 hour)

4 Count backwards 20 to 1 2 _____ x 2 _____

5 Say the months in reverse order 2 _____ x 2 _____

6 Repeat the memory phrase 5 _____ x 2 _____

In a study of 13 healthy elderly control subjects (mean age = 73.5), 12 subjects with very mild dementia (mean age = 72.5); and 12 subjects with mild dementia (mean age = 73.4), the correlation between the pass/fail outcome on an on-road driving evaluation and performance on the Short Blessed Test was significant at the p<.001 level (Hunt, Morris, Edwards, and Wilson, 1993).

The Short Blessed Cognitive Test was also employed in a study of 3,238 drivers ages 65 and older, who applied for renewal of their North Carolina driver's license (Stutts, Stewart, and Martell, 1996, 1997). Results of single variable models for the association of each cognitive test measure with recent prior crash involvement using continuous test scores (Chi Square Tests) showed that the Short Blessed test was not significant. Multivariate Poisson Regression Models were employed to control for effects of age, race, driving exposure, etc, and included Trails A, Trails B, and Short Blessed test. All three models fit the data adequately, although the Short Blessed was the least significant of the variables with an associated p-value of 0.48 (odds ratio= 1.10, 95% confidence interval= 1.01-1.19 for association of cognitive test with recent prior crash involvement). The researchers stated that the Short Blessed test was less sensitive to reduced cognitive function than the two Trails tests employed in this research, even though it is supposed to be relatively sensitive to milder levels of impairment. The short answer format may make it less appropriate for driver's license settings, compared to the more performance-based Trail Making and AARP Reaction Time Tests.

References:

• Hunt, Morris, Edwards, and Wilson (1993)

• Katzman, Brown, Fuld, Peck, Schechter, and Schimmel (1983)

• Stutts, Stewart, and Martell (1996, 1997)

Summary:

The CAST is a paper-and-pencil self-administered cognitive test, designed for use in general physicians' offices to screen geriatric patients for dementia (Drachman and Swearer, 1995). CAST was designed to require little (or no) examiner time, little examiner training, and sensitivity and specificity that are comparable to the best existing screening tests. Elderly patients with some high school education (a static representative of over 70 percent of the adult population) can complete the test in approximately 15 minutes without supervision in a physician's waiting room. The test is shown on the following 3 pages

The test has three one-page sections (Parts A, B, and C). Part A consists of 10 questions with 28 scored responses; Part B consists of 5 more-demanding questions, with 12 scored responses; and Part C has 13 self-report questions that assess the examinee's perception of a decline in memory and competence. The combined score of Parts A and B is used to determine whether performance falls within the normal range, or below the threshold for dementia. The subjective report of Part C identifies individuals who are concerned about age-related cognitive decline.

When tested in a "real world" population of elderly unscreened individuals followed in a medical geriatric clinic, a cut-off score of 36 had a sensitivity of 88 percent and a specificity of 100 percent. The test is viewed as an initial sort into 2 groups: elderly patients with probable dementia, and patients whose cognitive function is probably normal. The authors advise that patients who fall below the cut-off should be further evaluated with more extensive psychometric testing.

References:

• Drachman and Swearer (1995)

[ Cognitive Assessment Screening Test
Part A | Part B | Part C ]

Summary:

The 7 Minute Screen is a simple paper-and-pencil test designed to assist health care professionals in the identification of patients who should be further evaluated for Alzheimer's Disease. The test was developed by Dr. Paul Solomon, Professor of Psychology at Williams College and Co-Director of the Memory Clinic at Southwestern Vermont Medical Center, and his colleagues to address the under diagnosis of Alzheimer's Disease that can occur in a brief office visit, particularly in the early-to-moderate stages of AD. The goal was to create a unique testing battery that could be rapidly administered by office personnel following a brief training session (about 1 hour), be scored objectively, and not be sensitive to education level. The screen is the first in a two-step process, where the second step would be a full diagnostic evaluation for those "flagged" by the screen.

This test was recently applied to 120 people, and was found to be 90 percent accurate in the identification of individuals with Alzheimer's Disease. It identified 13 of 13 people known to have early Alzheimers, in the study where examiners were blind to diagnosis (Solomon, Hirschoff, Kelly, Relin, Brush, DeVeaux, and Pendlebury, 1998).

The subjects were sixty successive referrals to the Memory Disorders Clinic at Southwestern Vermont Medical Center, Bennington, who were diagnosed as having probable AD (mean age = 77.6, range = 66-89) and 60 community-dwelling volunteers of comparable age (mean age = 77.5, range = 67-91), sex distribution, and education. The main outcome measure was comparison of the probability of dementia on the 7 Minute Screen with the criterion standard of clinical diagnosis established by examination and laboratory studies. The secondary outcome measures were test-retest and interrater reliability (correlation coefficients), and time for administration.

The mean time of administration was 7 minutes 42 seconds. Mean scores for patients with AD and control subjects on all four individual tests were significantly different (for each, P<.001). When the four tests were combined in a logistic regression, the battery had a sensitivity of 100 percent and a specificity of 100 percent. A series of 1,000 repeated random samples of 30 patients with AD and 30 control subjects taken from the overall sample of 60 patients with AD and 60 control subjects had a mean sensitivity of 92 percent and a mean specificity of 96 percent. The battery was equally sensitive to patients with mild AD, as demonstrated by correctly classifying all 13 patients with AD using Mini-Mental State Examination scores of 24 or higher. Neither age nor education was a statistically significant factor when added as a covariate. Test-retest reliabilities for individual tests ranged from 0.83 to 0.93. Test-retest reliability for the entire battery was 0.91. Interrater reliability for the entire battery was 0.92.

Several large scale studies (up to 2,000 patients) are underway in primary care practices across the U.S. Information obtained from Janssen Pharmaceutica Research Foundation (the screening kit distributor) states that some primary care physicians have incorporated the 7 Minute Screen as a part of their annual physical for patients over the age of 65.

The test includes 4 quizzes that probe a patient's ability to recall words and images seen moments before, along with finding a solution to a simple clock problem. Reminder words are provided if needed. According to Dr. Solomon, few people can recall all of the categories, but a normal person will benefit from the reminder words. A person with Alzheimer's Disease will not find the reminder words helpful (The Morning Call, March 13, 1998).

The test battery:

Step 1. Patient is asked to state the correct year, month, date, day of week, and time. Perfect score is zero; maximum score is 113. Points are added for errors (e.g., 5 points are added for each month off, 1 point for each date off, 10 points for each year off, 1 point for each day off, 1 point for each 30 minutes off).

Step 2. Pictures of objects in 1 of 16 categories are presented to the patient, 4 at a time. The patient must respond with the name of the object when the examiner supplies the category. For example, the examiner says, "There is a piece of fruit on this page. What is it?" The patient would look at the page, and reply "Grapes." After the patient names each of the four objects, the examiner removes the four pictures and asks the patient to respond with the name of each of the four objects when the examiner supplies the category name. If the patient recalls all four items correctly, the examiner moves on to the next four items. If the patient makes a mistake on one or more items, the page of four items is shown again, with the cued recall and then the delayed recall. After all 16 items are displayed and recalled the examiner asks the patient to recite the months in reverse order, but the task is not scored. Then, the patient is asked to recall as many of the objects as possible. Reminder words such as "article of clothing" for the "shoe" object are provided by the examiner. Perfect score is 16.

Step 3. Patient is asked to draw a clock face, with numbers and to place the clock hands to read 20 minutes to 4:00. A point is given for correct numbers, their position, and for placement and length of clock hands. Perfect score is 7.

Step 4. Patient is asked to name, within 60 seconds, as many objects as possible within a single category, such as "vegetables." Scoring is one point for each correct response. Most people easily name 12 or more objects. The maximum score is 45 (for calculation purposes).

The screening kit contains a scoring calculator; the examiner enters the score for each test. The calculator performs a complex logarithmic process, and provides immediate output to assess a patient as normal or at low or high probability of Alzheimer's Disease.

The 7 Minute Screen Kit consists of a training video, testing materials, a scoring calculator, and score sheets (for recording performance for placement in a patient's record). Also included is a sheet that lists recommended laboratory and radiologic studies if a patient tests positive and a reprint of the Archives of Neurology article (Solomon, Hirschoff, Kelly, Relin, Brush, DeVeaux, and Pendlebury, 1998) that describes the validation of the Screen. The Screening kit is free of charge and is available to qualified health-care professionals. Distribution of the materials needed to administer and score the 7 Minute Screen is supported by Janssen Pharmaceutica Research Foundation. Two website addresses are provided with the materials: www.7minutescreen.com and http://phin.org.

References:

• Newspaper article: Alzheimer's Screening Test Developed, The Morning Call, March 13, 1998

• Solomon, Hirschoff, Kelly, Relin, Brush, DeVeaux, and Pendlebury (1998).

• 7 Minute Screening Kit

• Janssen Pharmaceutica Research Foundation, Janssen at Washington Crossing, 1125 Trenton-Harbourton Road, P.O. Box 200, Titusville, NJ 08560-0200.

IC2(b)ii. Psychophysical Test Batteries

Summary:

This program is in the public domain and is available without cost from: A. James McKnight and A. Scott McKnight, National Public Services Research Institute, 8201 Corporate Drive, Suite 220, Landover, MD 20785, (301) 731-9891 ext.101. It requires a 486 or better IBM-PC platform.

The APT is a computerized test of 22 visual, attentional, perceptual, cognitive and psychomotor abilities:

Sensory

Static Visual Acuity: to differentiate stimuli in high contrast images
Low Contrast Acuity: to differentiate stimuli in low contrast images
Dynamic Visual Acuity: to differentiate stimuli in moving images

Attentional

Range of Attention: to respond to presentation of parafoveal images (similar to "Useful Field of View")
Simple response: single response to the presence of images
Choice response: alternative responses to the form of images

• Simple image
• Complex image

Selective Attention: to shift attention from one characteristic of an image to another
Divided Attention: to share attention between images presented simultaneously

Perceptual

Perceptual Speed: to identify quickly a target image within an image field
Motion Detection: to detect direction of motion near the motion threshold
Field Dependence: to discern a figure within cluttered background ("embedded figures")

Cognitive

Information Processing: to perform mental operations with information

• Digit matching: to identify number series matching target series
• Figure matching: to identify figure matching target figure
• Missing pattern: to identify the pattern missing from an otherwise complete series

Short Term Memory: to recall information immediately after presentation

• Digit matching: to identify number series matching previous target series
• Figure matching: to identify figure matching previous target figure

Delayed Short Term Memory: to recall information after intervening tasks

• Digit matching: to identify number series matching previous target series after performing intervening tasks

Psychomotor

Simple Reaction Time: to respond quickly to appearance of a stimulus

• Abstract image: to respond to appearance of a square
• Meaningful image: to respond to appearance of brake lights

Choice Reaction Time: to respond quickly to the nature of a stimulus

• Abstract image: to respond directionally to the direction of arrows
• Meaningful image: to respond directionally to the pattern of brake lights

Visual Tracking: to track a laterally moving image in order to stop it at a designated point

Design features intended to facilitate its use by the elderly include the use of sound to give instructions, thereby permitting subjects to respond to visual stimuli as instructions are given rather than presenting instructions and test stimuli in sequence; use of a joy stick response system in which all responses correspond to directions on the screen, eliminating the need to learn response codes and minimizing response errors; and a sequencing system that allows subjects to repeat instructions as desired, as well as automatically repeating them after obvious errors or long delays. Familiarity with computers is not a factor in performance, as asymptotes are reached in a few trials of any exercise. To test the full range of abilities listed requires 30 to 60 minutes.

The individual exercises making up each APT measure are scored in terms of time and error. The time score on any exercise is the mean time on the individual exercises where the responses are correct. No times are recorded for incorrect responses. Those failing to respond within the time limit are assigned a score equal to the longest time of those correctly completing the exercise in order to prevent time scores from being unduly influenced by long latencies. For most exercises, error is a dichotomous measure to be scored correct or incorrect, and score on the measure is the proportion of responses that were incorrect. Two exceptions are visual acuity, where the correctness measure is the level of acuity and the visual tracking where it is the distance error averaged across exercises. Since visual tracking is also a component of the attention-sharing measure, results for that measure include both incorrect responses and distance error.

The APT was used in a study of 360 drivers age 62 and older who were currently licensed and driving (McKnight and McKnight, 1998). The subjects were divided into 2 groups:

"Incident-Involved." 249 drivers referred to licensing agencies for reexam by police, family, courts, physicians, and licensing personnel. The mean age was 80.6 years. Sixty percent of the group was male. Subjects with physical problems such as stroke, severe arthritis, or loss of consciousness were excluded.

"Incident-Free."111 drivers not previously referred for reexamination, obtained by solicitations through senior citizens groups. The mean age was 75.2 years. Sixty percent of the group was male.

The dependent variable was the presence or absence of a deficiency in driving performance, operationalized as observed incidents of deficient driving resulting in referrals to State licensing authority for reexamination. The correlations between unsafe driving incidents and performance on the APT is shown below. All correlations are positive, meaning that time and error were positively related to driving performance deficiency. All correlations given are significant at the .05 level while those in excess of .23 are significant at the .01 level (2-tail in both cases).

Correlation of Ability Measures with Unsafe Driving Incidents

 

Ability	Time	Error
Sensory Static Visual Acuity Low Contrast Acuity Dynamic Visual Acuity	.28 .21 .19	.18 .17 .19
Attentional
Range of Attention
Simple response	.20
Choice response
Simple image Complex image	.30 .33	.28 .23
Selective Attention	.29	.33
Divided Attention	.15	.33/.36d
Perceptual
Perceptual Speed	.28	.22
Motion Detection	.24	.35
Field dependence	.12	.23
Cognitive
Information Processing
Digit matching	.17	.40
Figure matching	.21	.30
Missing pattern	NS	.38
Short Term Memory
Digit matching	.31	.28
Figure matching	NS	.20
Delayed Short Term Memory
Digit matching	.28	.32
Psychomotor
Simple Reaction Time
Abstract image	.24
Meaningful image	.30
Choice Reaction Time
Abstract image	.33	.23
Meaningful image	.30	.37
Visual Tracking		.31d

^d = distance measure

Scores were aggregated across measures to obtain a measure of overall ability to compare with driving performance. In doing so, scores for all measures, both time and error, were standardized so that all would be equally weighted. With the composite measure, it was possible to establish a "passing" score such that 80 percent of the incident-involved drivers fell below it and 80 percent of the incident-free drivers exceeded it. A less demanding passing score found one-third of the incident-involved drivers failing but none of the incident-free drivers.

The authors describe two forms of implementation for the screening process. First, in its full form it could be administered to all individuals whose driving performance or general behavior give due cause to suspect age-related declines in ability that could pose a threat to themselves and the motoring public. In addition to the license referral process involved in the present study, the test might be administered by physicians, occupational therapists, and others working with elderly populations. Based upon the data that have been, and are still being gathered, it will be possible to reduce the number of exercises that must be administered to obtain acceptably reliable measures of the various abilities making up the test, allowing it to be completed in between 20 and 40 minutes, depending upon the ability of the individual.

The second form of administration might be as part of the regular license renewal process. Its integration into license renewal would permit detection of many deficient drivers who are not identified through the reexamination referral process or through private medical specialists without requiring special, age-based license testing. To be practical, the current APT would need to be modified to reduce testing time (~5 minutes in length) for the bulk of drivers. This could be accomplished through development of an adaptive testing method by which the great majority of license renewals, having no serious deficiencies, could be quickly identified and screened out of further testing. More complete testing would be confined to those with an elevated probability of serious deficiency.

References:

• McKnight and McKnight (1998)

Cognitive Behavioral Driver's Inventory (CBDI)

Summary:

The CBDI is a test battery that includes computerized and standardized psychometric tests (Engum, Pendergrass, Cron, Lambert, and Hulse, 1988). The standardized, nonautomated tests include the following: WAIS-R Picture Completion Test; WAIS-R Digit Symbol Test; and Trail-Making Test Parts A and B.

The computerized items are presented on an Atari 800 computer. Test software is adapted from Bracy's (1982, 1985) Cognitive Rehabilitation Programs (BCRP) for brain-injured and stroke patients, marketed through Psychological Software Service, Inc. (PSS). Computerized tests include:

• Visual Reaction Differential Response - The computer screen is bisected by a vertical line; a small dark square appears in random locations with random inter-trial interval. A subject pushes the joystick toward the side of the screen on which the square appears. Dependent variables are response time, variance, errors, and latencies in each visual quadrant. This test measures attention, concentration, reaction time.

•Visual Reaction Differential Response Reversed - Same as above, but a subject must push the joystick in the opposite direction. Measures attention, concentration, reaction time, dynamic cognitive processing, simple decision making. A radio, placed in a backroom provides auditory distractors.

•Visual Discrimination Differential Response II - Three squares are presented on the screen. The subject fixates on the center square and moves the joystick toward the square that turns the same color as the center square. Measures rapid decision-making and stimulus discrimination/response differentiation.

•Visual Scanning III - Two columns of alpha characters are shown, one on each side of the screen. Starting in the left column, a character group is highlighted, and the subject must find the matching character group in the right column and move the cursor to it. This procedure repeats for 20 trials using alternative sides for the initial stimulus. Measures ability to shift attention from one stimulus set to another and back.

Vision is also measured in the research using the Keystone Driver Vision Tester (far visual acuity, color vision) and the Keystone Perimeter Field of Vision (measures up to 90 degrees on each side of fixation point).

The 10 tasks yield 27 response measures. A score termed "General Driving Index" (or "GDI27") was defined as the mean standard score of all 27 items.

A road test is given to assess basic vehicle control operations, attitudinal variables (subjectively evaluated), reactions under pressure or stress, and cognitive variables such as ability to follow directions, safety awareness, ability to find one's way around a designated circuit, and problem solving.

The CBDI was employed in a study of 92 brain- or spinal-cord injured patients from the Center for Outpatient Rehabilitation in Knoxville, TN: 61 percent had suffered a stroke, 21 percent had suffered traumatic brain injury, and 6 percent had suffered spinal cord injury (Engum, Pendergrass, Cron, Lambert, and Hulse, 1988). The internal consistency reliability of the CBDI was 0.95 (Cronbach's alpha). The correlation between performance on the CBDI (GDI27) and road test performance was significant (²=86, Cramer's V=0.97, p<.0001). Of the 44 patients who passed the CBDI, 42 passed the road test (95.5%). Of the 48 patients who failed the CBDI, only 6 were allowed to take the road test. All 6 patients "convincingly" failed the road test.

In another study of 121 brain-injured patients (cerebral vascular accident and traumatic head injury victims) at Fort Sanders Regional Medical Center in Knoxville, TN, two scores were calculated for each patient: (1) the overall General Driver's Index (GDI27) defined as the mean standard score of all 27 variables; and (2) the short form Abbreviated Driver's Index (ADI10), defined as the mean standard score of those 10 items with the highest corrected part-whole correlations. The 10 best items with corrected part-whole correlations (which measure how closely a given item correlates with all other items excluding itself) were:

• Trails B Time

• WAIS Digit Symbol (N correct)

• Visual Reaction Differential Response: joy stick to square (ave. time, Q1 time, and Q3 time)

• Visual Reaction Differential Response Reverse: joy stick away (ave time, Q1 time, Q3 time, and Q4 time)

• Left Visual Scanning III (time)

Both the GDI27 and ADI10 have a mean of 50 and a standard deviation of 10, with scores above 50 indicating greater levels of disability (Engum, Lambert, Womac, and Pendergrass, 1988). Patients were given the CBDI and then an on-road driving test. Results are as follows. The short form ADI10 scores and long form GDI27 scores were very closely related [r(GDI27, ADI10)=0.97 (p<.001)]. Above average scores on the CBDI (>50 indicates more deficit) were more likely to occur in patients who failed the road test, while below average scores (< 50 indicates less deficit) were more likely to occur in patients who passed the road test. Sixty-three of 121 patients passed the on-road exam. Patients who passed had average GDI27 and ADI10 standard scores of 45. Patients who failed the on-road exam had average standard scores of 55.

An indeterminate region with standard scores ranging from 47-52 has an overlap of passing and failing distributions. A patient with a standard score in this "zone of uncertainty" is almost equally likely to have passed or failed in the examiner's opinion. Patients who obtained a standard GDI27 score of 47 or below passed the on-road test 100 percent of the time. Patients who obtained a standard GDI27 score of 53 or above failed the on-road test 100 percent of the time. The following decision-making criteria are suggested: standard scores of 46 or less are clearly passing; standard scores of 47-52 are borderline; and standard scores of 53 or greater are clearly failing. Borderline test scores on the CBDI are not definitive and an examiner should judge these cases with information independent of the CBDI, such as a road test, behavioral observations, or other neuropsychological tests.

In a double-blind validation study using 175 brain-injured patients (Engum, Lambert, Scott, Pendergrass, and Womac, 1989), the relationship between CBDI performance (pass, borderline, fail) and the on-road evaluation outcome (pass, fail) was significant (r=0.81, p<.0001). Of the 42 patients who received a favorable "pass" decision based on CBDI performance, 40 passed the on-road exam. Only 7 of the 39 patients who received an unfavorable "fail" rating on the CBDI passed the on-road test. Patients who passed the road test passed significantly more CBDI items (mean = 17.1) than those who failed the road test (mean = 6.3). Patients who failed the road test failed significantly more CBDI items (mean = 11.7) than those who passed the road test (mean = 1.7). Patients who passed the road test produced much less scatter or within-subject variability (mean = 16.76) in their responses than those who failed the road test (mean = 82.33).

The researchers conducted another study to determine whether the CBDI would discriminate between 3 discrete groups: (1) those brain-injured persons whose residual cognitive impairments preclude them from driving; (2) those brain-injured individuals who have recovered sufficient cognitive function that they should be allowed to resume driving; and (3) normal control subjects without brain damage (Engum and Lambert, 1990). Subjects underwent examination on the CBDI and were then are assessed on the road. The 215 rehabilitation patients had a mean age of 47.8 years; the 41 control subjects had a mean age of 31.15 years. Five summary scores were calculated from the CBDI:

(1) GDI27 - the average of the patient's 27 CBDI item scores; (2) within subject variance; (3) number of items passed; (4) number of items borderline; and (5) number of items failed. All 5 summary scores, plus 25 of the 27 item scores significantly discriminated the 215 brain-injured patients from the 41 normal controls (p<.05). The 109 patients who passed the road test performed significantly better on all 27 items of the CBDI, and 4 of the 5 summary scores than the 54 patients who failed the road test (p<.01). The sole exception was for the number of borderline items, which was unrelated to road test performance. After removing the confounding effects of age, 20 of 27 item scores and 4 of 5 summary scores continued to differentiate patients from controls. Five of the seven that failed to differentiate pertained to number of errors (various Visual Reaction and Scanning tests). Average GDI27 performance for controls (42.09) was superior to that of patients passing road test (45.75), which was, in turn, superior to patients who failed road test (54.23).

References:

• Engum, Pendergrass, Cron, Lambert, and Hulse (1988)

• Engum, Lambert, Womac, and Pendergrass (1988)

• Engum, Lambert, Scott, Pendergrass, and Womac (1989)

• Engum, Lambert, and Scott (1990)

DrivAble Testing

Summary:

The (cognitive) competence screen is presented on a touch screen computer, and takes 20-30 minutes to administer (DrivAble Testing, Ltd., 1997). Tasks require multiple mental abilities and integration and shifting among these abilities. Tests include:

• a selective attention task;

• an assessment of judgment/decision making using a Gap Task (designed by research team);

• visual attention, using a version of UFOV (Ball et al., 1994);

• a spatial working memory task;

• a simple and choice reaction time test; and

• Weaver's Driving Video (selected and revised driving scenarios).

Two competence scores are generated: The high cut-off score identifies the performance level necessary to accurately predict that the driver would pass the road test; the low cut-off score identifies the performance level below which accurate predictions of failing road-test performance can be achieved. The road test would only need to be administered to those who score in the mid range on the competence screen (and, depending on the jurisdiction, for those who fail the competence screen but want a road test as due process).

A road test was administered by 2 experienced driving instructors from the Canadian Automobile Association. Testing was conducted in a mid-sized American car equipped with dual brakes. Definition and scoring of errors was as follows:

• Hazardous or potentially catastrophic driving errors: errors committed by drivers who are no longer competent to drive (e.g., wrong-way on a freeway, stop at green light), and would result in a crash if examiner did not intervene or traffic did not adjust.

• Discriminating driving errors: potentially dangerous errors that signal declining driving skill (e.g., poor positioning on turns and straight aways, observational errors).

• Non-discriminating driving errors: errors made equally often by good and bad drivers, reflecting bad habits as opposed to declining ability (e.g., rolled stops and speed errors). Drivers are not penalized for non-discriminating errors. Discriminating errors are documented and scored in terms of their severity (5, 10, or 51 points). Hazardous errors were renamed as Criterion errors and the commission results in an automatic fail. A combined criterion of one or more criterion errors and/or discriminating point total exceeding criterion, results in a failure on the road test.

In the test development research 279 drivers were assessed across three groups: 176 patients who were referred to a clinic with suspected decline in mental abilities (the majority were diagnosed with Alzheimer's) with a mean age of 72 years; 70 mature healthy drivers who volunteered for the research, with a mean age of 69 years; and 33 young healthy controls who also volunteered, ranging in age from 30 to 40 years, with a mean age of 36 years. Subjects in the development research were used to develop road test procedures and scoring. The majority of the drivers who failed the road test received low scores (poor performance) on the cognitive screen; the majority of the drivers who passed the road test received high scores (good performance) on the cognitive screen.

Validation research included 431 drivers. The cut-off scores identified in the original research for the competence screen were 94 percent accurate in predicting actual pass/fail performance on the road test. Only 33 percent of those tested had Competence Screen scores falling below the high and low cut-off scores. Analysis of the road test errors revealed the same categories of errors and verified the effectiveness of the road test for revealing the errors among unsafe drivers. Using the joint criterion, all of the young normal drivers passed the road test, approximately 95 percent of the mature control group drivers passed the road test, and only 25 percent of the cognitively impaired (patient) group passed the road test.

The Competency Screen resulted in a 5 percent error in predicted road test performance: it predicted a pass for 29 of the 33 drivers who passed the road test, and predicted a fail for 33 of the 34 drivers who failed the drive test. The screen reduced the number of drivers who needed to be tested by 67 percent. Only 33 percent of the drivers in the sample received an indeterminate score on the competence screen: 54 percent of the indeterminate drivers passed the road test and 45 percent failed the road test.

References:

• DrivAble Testing Ltd (1997)., Suite 200, 18208 102 Avenue, Edmonton, Alberta, Canada, T5S 1S7. Phone: (403) 413-1909; fax: (403) 413-8916

• Dobbs (1997)

The Neurocognitive Driving Test (NDT)

Summary:

The NDT is a new computerized task designed to provide an ecologically valid measure of driving ability based on Michon's Hierarchical Model of Driving Behavior. It has recently been administered at Moss Rehab Driving School, a branch of the Moss Rehab Hospital Philadelphia, Pennsylvania (Schultheis and Chute, 1998). The NDT is divided into five sections as follows, with a total performance score calculated using variables from each section:

I. Self Evaluation: Includes 5 questions involving self-rating of driving skills.

II. Pre-Driving Questions: Includes 12 multiple choice and open-ended questions, with both linguistic and graphic stimuli designed to target an individual's ability to correctly identify important information needed prior to engaging in driving (i.e., check gas in car, have correct paperwork).

III. Reaction Time Task: Includes a total of 24 counter-balanced trials, 12 measuring simple reaction time (6 left-foot trials and 6 right-foot trials) and 12 measuring choice reaction time.

IV. Driving Scenario Task: Includes the presentation of 4 driving scenarios, which the subject "drives" through with the use of an attached steering wheel and foot pedals. They include: (1) Following Signs; (2) Emergency Situation; (3) Following Verbal Directions; and (4) Following Written Directions.

V. Visual Task: Includes a visual task, designed to assess an individual's left and right visual fields for gross field cuts or visual inattention. The subject is asked to stare at a small black box in the center of a blank screen. When the task begins, a small dot flashes at various locations on the computer screen. If the subject sees the dot, he/she is required to respond by stepping on the right (green) foot pedal.

All participants were between 18 and 60 years of age, with a minimum of one year of driving experience and no prior medical or psychiatric history. The subjects included 15 brain-injured (BI) adults and 26 healthy adults. The BI adults were 10 men and 5 women with a mean age of 38.6 years (range= 21-59 years) and mean education level of 14.3 years. Their mean number of years of driving experience prior to their injury was 21.0, and at the time of testing only four individuals had not returned to driving. The 26 healthy adults included 18 males and 8 females, with a mean age of 27.7 years (range= 18-45 years) and a mean education level of 14.5 years. All subjects had a valid driver's licenses at the time of testing. The mean number of years of driving was 10.7.

All brain-injured subjects were administered both a hospital-based driving evaluation and the NDT.

The hospital-based evaluation included performance of various off-road and behind-the-wheel evaluations. Subjects were then separately rank ordered based on their overall performance rating in the hospital evaluation and on their NDT Total Performance score. A comparison of the rank ordering was conducted using a Spearman Rank Order Correlation. Healthy subjects received only the NDT. Mean and standard deviation of healthy-subject performance was calculated for comparison with performance by BI subjects.

A positive correlation (p = 0.743), was found between the rank order generated by the hospital-based evaluation and the rank order generated by the NDT for BI subjects. Of the 15 BI subjects, the NDT accurately predicted 10/11 subjects who passed the hospital-based evaluation and placed the four individuals who failed the hospital evaluation at the lower end of the rank order. The subject ranked lowest by the NDT was the lowest ranked passing subject by the hospital evaluation.

A comparison of NDT total performance between BI and healthy subjects was calculated by a simple factorial ANOVA covarying for age, and revealed a significant difference between BI subjects who passed the hospital evaluation and normal subjects (p= .034). Additionally, it was observed that BI subjects who failed the hospital evaluation exhibited poorer NDT performance then both normal subjects and BI subjects who had passed.

This first concurrent validity study involved 15 BI subjects, who were administered the NDT and a comprehensive hospital-based evaluation. The results demonstrate a significant correlation between the rank order of driving ability generated by the hospital driving evaluation and the rank order of driving ability generated by the NDT Total score. This comparison demonstrates the ability of the NDT to determine the rank order of driving ability, as determined by a presently accepted measure of driving ability (e.g. hospital-based evaluation). The correlation of the two rank orders suggests that both programs are targeting similar skills, which at present serve as the criterion to whether an individual is able to return to driving after a brain injury.

References:

• Schultheis and Chute (1998).

IC2(b)iii. Ophthalmological/Optometric Examination

An optometrist is a health care professional trained and state licensed to provide primary eye care services. These services include comprehensive eye health and vision exams; diagnosis and treatment of eye diseases and vision disorders; the detection of general health problems; the prescribing of glasses, contact lenses, low vision rehabilitation, vision therapy, and medications; and the counseling of patients regarding their surgical alternatives and vision needs as related to their occupations, avocations, and lifestyle. Doctors of optometry provide 70 percent of primary eye and vision care services in this country and far outnumber any other eye care practitioners (American Optometric Association, 1996)

The optometrist has completed pre-professional undergraduate education in a college of optometry, leading to a doctor of optometry (O.D.) degree. Some optometrists complete a residency. All States require at least 15 hours of continuing education each year for license renewal. All 50 States and DC have legislation authorizing doctors of optometry who have satisfactorily completed specific education courses and examinations to use pharmaceutical agents in the evaluation and diagnosis of conditions of the eye and visual system. Also, all 50 States have legislation authorizing doctors of optometry to use drugs to treat certain eye conditions. Doctors of optometry work closely with other professionals by consulting with family practitioners, pediatricians, neurologists, ophthalmologists, dermatologists, and others when treatment is required outside the scope of their practices. This consultation process is two-way, and as the health care delivery system continues to change, this interprofessional consultation and concurrent care will become more important.

An ophthalmologist is a medical doctor (MD or osteopath) who is educated, trained, and licensed to provide total care of the eyes (medical, surgical, and optical), including: performing comprehensive medical eye examinations; prescribing corrective lenses; diagnosing diseases and disorders of the eye; and using the appropriate medical and surgical procedures necessary for their treatment. Retinal specialists are ophthalmologists with extra training and experience in treating disease affecting the retina such as diabetic retinopathy.

Vision Examinations: Content and Frequency

Because primary care physicians provide only a vision screening (distance acuity, questions on seeing difficulties, and a check with an ophthalmoscope), people are advised by the AOA to get a thorough eye exam every year or two from an optometrist that will include:

• A review of family and personal health history, including any problems the individual is having with vision;

• Tests to determine how well the individual can see at near and far distances;

• Tests to determine nearsightedness, farsightedness and astigmatism (a refraction) and if there is a problem, a lens prescription to correct for it;

• A check of eye coordination and eye muscle function;

• Tests of ability to change focus easily from near to far and vice versa and to maintain clear focus for reading and other close work;

• An eye health examination, involving a number of tests (in some cases, the eyes may be dilated for this part of the exam).

AOA recommends that people ages 10 to 40 see an optometrist every 2 to 3 years; people ages 41 to 60 every two years; and people age 61 and older every year (AOA, 1996). Individuals age 61 and older have an increasing risk for the development of cataracts, glaucoma, and macular degeneration and other sight threatening or visually disabling eye conditions as well as systematic health conditions. Additionally, people age 65 and older who are diagnosed with diabetes or hypertension; those who have a family history of glaucoma or cataracts; and those taking prescription or nonprescription drugs with ocular side effects should follow their optometrist's advise on how often they need professional care.

Eye Diseases

Diabetic Retinopathy. Diabetic retinopathy is a complication of diabetes mellitus, caused by the deterioration of the blood vessels nourishing the retina (American Academy of Ophthalmology, 1984). These weakened blood vessels may leak fluid or blood, develop fragile brush-like branches, and become enlarged in certain places. The risk of developing diabetic retinopathy is high for patients who have had diabetes for a long time. Approximately 60 percent of patients having diabetes for 15 years or more have some blood vessel damage in their eyes. Diabetic eye disease remains the leading cause of blindness in the U.S. for adults between the ages of 20 and 74 years. Pregnancy, high blood pressure, poor control of diabetes, ethnic influences, and smoking may worsen this condition in diabetic patients.

Though gradual blurring of vision may occur, sight is usually unaffected by background retinopathy (early stage that does not progress in 80 percent of diabetic patients), and changes in the eye can go unnoticed unless detected by a medical eye condition. When bleeding occurs in proliferative retinopathy, the patient has hazy or complete loss of sight. Though there is no symptom or pain, this severe form of diabetic retinopathy requires immediate medical attention.

To detect diabetic retinopathy, an ophthalmologist painlessly examines the interior of the eye using an instrument called an ophthalmoscope. The interior of the eye may also be photographed to provide further information. If diabetic retinopathy is noted, a second method of examination may be used to see which blood vessels are bleeding or leaking fluid. A fluorescent dye is injected into the patient's arm. It travels through the bloodstream and passes into the blood vessels of the retina. Photographs are taken rapidly of the dye as it leaks through the retina's blood vessels. This treatment is called fluorescein angiography.

The most significant treatment is the use of ophthalmologic laser surgery to seal or photocoagulate the leaking blood vessels. This treatment does not require an incision and may be performed in an ophthalmologist's office. If diabetic retinopathy is detected early, photocoagulation by ophthalmologic laser surgery may stop continued damage. Even in advanced stages of the disease, it can reduce the chance that a patient will have severe loss. However, photocoagulation cannot be used in all patients. Depending on the location and extent of diabetic retinopathy, and if the vitreous is too clouded with blood, a surgical treatment called vitrectomy can be performed. The blood-filled vitreous is removed from the eye and replaced with a clear artificial solution. About 70 percent of vitrectomy patients notice an improvement in sight. Successful treatment depends on early detection with monitoring and treatment by an ophthalmologist, in addition to the patient following diet and medication recommendations. Although physical activity presents few problems with background retinopathy, it can increase bleeding in proliferative retinopathy. Exercise for patients with proliferative retinopathy should be moderate, and straining or leaning over with the head down should be avoided.

Macular Degeneration. The retina is the delicate layer of tissue that lines the inside wall of the back of the eye. The macula is a very small area in the center of the retina. If the macula is damaged, the central part of the images are blocked/blurred. The images around the blurred area may be clearly visible. Macular degeneration does not result in total blindness, but it makes reading or close work difficult to impossible without special low vision optical aids. Although macular degeneration most often occurs in older people, aging alone does not always result in central visual loss. The most common form of macular degeneration is called involutional macular degeneration; this form accounts for 70 percent of all cases and is associated with aging (American Academy of Ophthalmology, 1984).

Many patients do not realize they have a macular problem until blurred vision becomes obvious. An ophthalmologist can detect macular degeneration in the early stages by viewing it with an ophthalmoscope, if periodic eye exams are part of the patient's health care. The examination will also include a grid test in which the patient looks at a test page similar to graph paper; this checks for the extent of sight loss spots. A color vision test may be employed, as color vision dimming is also a symptom of macular degeneration. A fluorescein angiogram may also be done, as described earlier.

There is no cure for the most common involutional form of macular degeneration. Low vision optical aids help improve vision. Many types of magnifying devices are available: spectacles, hand or stand magnifiers, telescopes, and closed circuit television for viewing objects are some of the available sources. Aids are either prescribed by an ophthalmologist or by referral to a low vision specialist or center. People over age 50 and people with a family history of retinal problems should have periodic eye exams that check for macular degeneration.

Glaucoma. Glaucoma is one of the leading causes of blindness in the U.S., affecting 2 out of every 100 persons over age 35 (American Academy of Ophthalmology, 1983). When diagnosed early, blindness from glaucoma is almost preventable. Glaucoma occurs when the drainage system of the eye gets blocked and fluid pressure within the inner eye increases, causing damage to the optic nerve. Most adult glaucoma patients have "chronic open-angle glaucoma" which is a partial blockage that causes a gradual increase of pressure within the eye. According to the American Academy of Ophthalmology (1983) it is seldomly accompanied by symptoms, "stealing vision so quietly that the patient is unaware of trouble until the optic nerve is badly damaged." Factors increasing the risk of damage include a family history of glaucoma, and general health problems such as diabetes, arteriosclerosis, or anemia.

Early diagnosis can be made in the course of a periodic eye examination, by an ophthalmologist who determines the pressure of the eye during a painless procedure. The fields of vision will be tested for shrinkage or blind spots, and an ophthalmoscope will be used to examine the optic nerve.

Glaucoma is usually controlled by eye drops given 2 to 4 times per day or by pills in various combinations, to decrease pressure either by assisting outflow of fluid from the eye or by decreasing the amount of fluid entering the eye. If medications are poorly tolerated or ineffective in controlling pressure in open-angle glaucoma, surgery can be performed to form a new drainage canal in the eye.

The American Academy of Ophthalmology recommends that persons over age 35 be checked for glaucoma every 2 or 3 years.

Cataract. A cataract is a clouding of the normally clear and transparent lens of the eye, that usually develops gradually over many years (American Academy of Ophthalmology, 1984). It may cover only a small part of the lens; if sight is not greatly impaired, there may be no need to remove the cataract. Alternatively, if a large portion of the lens becomes cloudy, sight can be partially or completely lost until the cataract is removed. Depending on the size and location of the cloudy area in a lens, a person may or may not be aware that a cataract is developing. As cataracts develop, there may be hazy, fuzzy, and blurred vision. Double vision may also occur when a cataract is beginning to form. The eyes may be more sensitive to light and glare making night driving difficult.

Most cataracts are caused by a change in the chemical composition of the lens, resulting in a loss of transparency. These changes can be caused by aging, injuries to the eye, certain diseases and conditions of the eye and body, and heredity or birth defects. The normal process of aging may cause the lens to harden and turn cloudy. These are called senile cataracts and are the most common type, occurring as early as age 40. The American Academy of Ophthalmology recommends that persons over age 40 with a family history of cataracts have their eyes checked periodically to detect signs of eye disorders, including cataracts.

A cataract usually cannot be detected by looking at the outside of the eye; proper instruments are required. Surgery is the only effective way to remove the cloudy lens. Once the cloudy natural lens of the eye is removed, the patient needs a substitute lens to focus the eye. These may include special cataract glasses, hard or soft contact lenses, or interocular lenses (IOLs) that are permanent lenses implanted inside the eye by surgery, in place of the natural lenses.

References:

• American Optometric Association (AOA): Definition of Doctor of Optometry

• AOA (1996): Vision Screening vs. Vision Examination

• American Academy of Ophthalmology (1984): Macular Degeneration

• American Academy of Ophthalmology (1984): Diabetic Retinopathy

• American Academy of Ophthalmology (1983): Glaucoma

• American Academy of Ophthalmology (1984): Cataract

IC2(b)iv. Simulator Measures of Response Effectiveness

Iowa Driving Simulator (IDS)

The IDS is a realistic ground-vehicle simulator that provides 190 degrees in the forward field of view and 65 degrees in the rear view. Multiple roadway types, traffic signals, traffic conditions, and vehicles can be displayed. These vehicles interact with the driver and each other according to a particular set of rules dictated by the experimental driving scenario. Acceleration speeds of up to 1.1g produce a majority of the movement cues experienced during normal driving. The steering wheel, accelerator, brake pedal, and gearshift positions are read by the host computer to give feedback to the driver and allow him/her to control the driving simulation.

This simulator was used in a study of 39 licensed drivers (21 with Alzheimer's Disease and 18 controls without dementia) to determine fitness to drive for neurological patients (Rizzo, Reinach, McGehee, and Dawson, 1997). The study had three goals: (1) to test the hypothesis that drivers with AD are more at risk for crashes than controls of similar ages wit