| Medical conditions, diabetes in particular, and medications are hypothesized determinants of crash involvement among the elderly. This study sought to identify medical conditions and medications associated with risk of at-fault automobile crashes among older drivers. A population-based case-control study was conducted wherein case subjects were drivers aged 65 years and older who had been involved in crashes during 1996 where they were at fault. Two control groups were selected: (1) crash involved, not at-fault subjects and (2) non-crash involved subjects. Information on demographic factors, chronic medical conditions, medications, driving habits, visual function, and cognitive status was collected through telephone interviews. At-fault crash involvement was associated with certain medical conditions and medications. Heart disease (odds ratio (OR), 1.5 (95% CI, 1.0 to 2.2)) and stroke (OR, 1.9 (CI, 0.9 to 3.9)) were associated with at-fault automobile crashes. There was no overall association between diabetes and at-fault crash involvement (OR, 1.1 (CI, 0.7 to 1.9)) when cases were compared to either control group. Among subjects who had been in a crash between 1991 and 1995, the adjusted OR for diabetes was 2.5 (CI, 0.9 to 7.2), and only 0.9 (CI, 0.5 to 1.7) among those who had not. Associations between treatment modalities and at-fault crash involvement were not observed. Cases were slightly, but not significantly, more likely (OR = 2.4) (P = 0.25) to report neuropathy compared to both control groups; retinopathy was not associated with increased crash risk. Use of non-steroidal anti-inflammatory drugs (OR, 1.7 (CI, 1.0 to 2.6)), ACE inhibitors (OR, 1.6 (CI, 1.0 to 2.7)), and anticoagulants (OR, 2.6 (CI, 1.0 to 73)) was associated with increased risk of at-fault crash involvement. Benzodiazepine use (OR, 5.2 (CI, 0.9 to 30.0)) was also associated with an increased risk. Calcium channel blockers (OR, 0.5 (CI, 0.2 to 0.9)) and vasodilators (OR, 0.3 (CI, 0.1 to 0.9)) were associated with reduced risk of crash involvement. Future research should elucidate the nature of these conditions that place older drivers at increased risk of at-fault crash involvement. |
