Article

We investigated the psychometric properties of the 68-item Safe Driving Behavior
Measure (SDBM) with 80 older drivers, 80 caregivers, and 2 evaluators from two
sites. Using Rasch analysis, we examined unidimensionality and local dependence;
rating scale; item- and person-level psychometrics; and item hierarchy of older
drivers, caregivers, and driving evaluators who had completed the SDBM. The
evidence suggested the SDBM is unidimensional, but pairs of items showed local
dependency. Across the three rater groups, the data showed good person (>/=3.4)
and item (>/=3.6) separation as well as good person (>/=.93) and item reliability
(>/=.92). Cronbach's alpha was >/=.96, and few items were misfitting. Some of the
items did not follow the hypothesized order of item difficulty. The SDBM
classified the older drivers into six ability levels, but to fully calibrate the
instrument it must be refined in terms of its items (e.g., item exclusion) and
then tested among participants of lesser ability.
CI - Copyright (c) 2012 by the American Occupational Therapy Association, Inc.

Langue : ANGLAIS