Conceptualizing and measuring confidence in older drivers: development of the day and night driving comfort scales.
OBJECTIVE
To examine and measure driving confidence from the perspective of older adults.


METHODS
Used focus groups for construct examination, item generation, and ratings; conducted psychometric testing using Rasch analysis for scale refinement; examined test-retest reliability and associations with driver characteristics and driving habits.


METHODS
Retirement complexes and seniors' housing and centers in Ontario, Canada.


METHODS
Convenience samples of current drivers (n=143) (range, 66-92y) and 7 counselors.


METHODS
Not applicable.


METHODS
The Day (DCS-D) and Night (DCS-N) Driving Comfort Scales developed inductively with older drivers.


RESULTS
Older drivers believed that it was important to consider confidence in their own abilities and discomfort caused by other drivers, to separate day and night driving, and to specify the driving context (eg, traffic flow, speed). Rasch analysis showed that the final 13-item DCS-D and 16-item DCS-N were both hierarchic and unidimensional, with good person (.89, .96) and item (.98, .97) reliabilities, respectively. Test-retest reliability was adequate for the DCS-D (intraclass correlation coefficient [ICC]=.7) and good for the DCS-N (ICC=.88). Scores were significantly associated with reported driving frequency, situational avoidance, and perceived abilities (P<.001).


CONCLUSIONS
The Driving Comfort Scales are promising new tools for research and practice.
Myers
Anita M
AM
Department of Health Studies and Gerontology, University of Waterloo, Waterloo, ON, Canada. amyers@healthy.uwaterloo.ca
Paradis
Josee A
JA
Blanchard
Robin A
RA
D000063:Accidents, Traffic / Q000517:prevention & control; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001333:Automobile Driver Examination; D001334:Automobile Driving / Q000523:psychology* / Q000592:standards; D002940:Circadian Rhythm; D015331:Cohort Studies; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D017144:Focus Groups; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D009755:Night Blindness; D011336:Probability; D011594:Psychometrics; D015203:Reproducibility of Results; D018570:Risk Assessment; D012424:Rural Population; D012649:Self Concept; D012680:Sensitivity and Specificity; D013647:Task Performance and Analysis; D014505:Urban Population