Drawing clocks and driving cars.
OBJECTIVE
The purpose of the study was to determine whether a new method of scoring the Clock Drawing Test (CDT) is a reliable and valid method for identifying older adults with declining driving competence.


METHODS
Prospective cohort study.


METHODS
An outpatient driving evaluation clinic.


METHODS
One hundred nineteen community-dwelling, active drivers with a valid driver's license, aged 60 and older referred for driving evaluation.


METHODS
The CDT and a driving test using a STISIM Drive simulator.


RESULTS
The CDT showed a high level of accuracy in predicting driving simulation outcome (area under the receiver-operator curve, 0.90; 95% confidence interval, 0.82 to 0.95). CDT scoring scales were comparable and all correlations between CDT scores and driving performance were negative, implying that as the CDT score decreases, the number of errors increases. Interrater reliability of CDT scores was 0.95. Subjects scoring less than 5 out of 7 points on the CDT made significantly more driving errors, hazardous and in total (P<.001).


CONCLUSIONS
The CDT can help establish problems with executive function and indicate the need for a formal driving evaluation. Our CDT scoring scale is a reliable, valid, and time-effective screening tool for identifying elderly drivers in need of further evaluation.
Freund
Barbara
B
The Glennan Center for Geriatrics and Gerontology, Eastern Virginia Medical School, Norfolk, VA, USA. freundbm@evms.edu <freundbm@evms.edu>
Gravenstein
Stefan
S
Ferris
Rebecca
R
Burke
Bonnie L
BL
Shaheen
Elias
E
D000368:Aged; D000369:Aged, 80 and over; D001334:Automobile Driving; D003072:Cognition Disorders / Q000175:diagnosis*; D003704:Dementia / Q000175:diagnosis; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013647:Task Performance and Analysis