The study objective was examination and measurement of older adult driving confidence. Study design constructed an examination, item generation, and rating through focus groups; used Rasch analysis for scale refinement in conducting psychometric testing; and examined how driver characteristics and driving habits were associated with testing-retesting, as well as the latter's reliability. Study setting was senior housing, senior centers, and retirement complexes in Ontario, Canada. Study participants were drawn from convenience samples of seven counsellors, as well as current drivers (n=143) (range: 66-92 years). Main outcome measurement was obtained using the inductively-developed Day (DCS-D) and Night (DCS-N) Driving Comfort Scales. Study results show that older drivers believed in the importance of specifying driving context (e.g., traffic flow, speed), of separating day and night driving, and of considering confidence in their own abilities and discomfort caused by other drivers. Rasch analysis showed both hierarchical and unidimensional aspects to the final 16-item DCS-N and 13-item DCS-D,with good respective person (.96, .89) and item (.97, .98) reliabilities.Test-retest reliability was good for the DCS-N (intraclass correlation coefficient [ICC]=.88) and adequate for the DCS-D (ICC=.7). There was significant association between scores and perceived abilities, situational avoidance, and reported driving frequency. The authors conclude that for research and practice, the Driving Comfort Scales are promising new tools.
Abstract