Book Description
Introduction: Bandura's self-efficacy theory postulates that confidence is a stronger determinant of behaviour than one's actual skills or abilities. The Day and Night time Driving Comfort Scales (D-DCS and N-DCS) are new tools to measure perceived confidence in older drivers. Developed inductively with older drivers, the DCSs have good structural properties and preliminary psychometric support, including test-retest reliability. Purpose: This thesis builds on previous work by further examining the construct validity of the DCSs via (1) temporal associations (Study 1) and (2) cross-sectional relationships (Study 2). Study 1 prospectively examined the relationship between DCS scores and self-reported driving behaviour. Study 2, meanwhile, examined cross-sectional associations between DCS scores and selected sample characteristics, self-reported driving behaviour and driving problems, perceived abilities and seven objectively measured driving-related abilities (visual acuity, contrast sensitivity, disability glare, brake reaction time, lower body mobility, executive skills and visual attention). Methods: For Study 1, a convenience sample of 82 older drivers (aged 63 to 93) were assessed at baseline and follow-up (five to 17 months later). Study tools comprised the DCSs, multi-item ratings of driving frequency, avoidance and perceived abilities and a background questionnaire. Telephone interviews were conducted with a subgroup of 45 drivers to examine reasons for changes in driving comfort. For Study 2, cross-sectional relationships with the DCSs were examined using baseline data from 65 drivers (aged 63 to 93). A subgroup of 42 participants completed objective assessments of driving-related abilities assessed via ETDRS charts, Pelli-Robson charts, Brightness Acuity Tester, brake reaction time apparatus, the Rapid Paced Walk, the Trail Making Tests (Parts A and B) and the UFOV subtest 2. Results: Prospectively, lower baseline N-DCS scores (p