Objective: To examine whether male drivers aged 45 to 70 years suffering from cardiovascular disease (CVD) are more likely to be involved in motor vehicle crashes (MVC) that are reported to the police.
Design: Population-based case-control study.
Setting: Data on drivers' ages and medical conditions were compiled from the Societé de l'assurance automobile du Québec's (SAAQ) computerized files. A questionnaire was mailed to all subjects to collect additional information on annual distances driven and various driving behaviours.
Participants: Age-stratified population-based random sample. Subjects were 2504 drivers involved in MVCs during a 6-month period; controls were 2520 drivers not involved in crashes.
Main outcome measures: Proportion of drivers with CVD involved in MVCs.
Results: Response rate to the questionnaire was 35.5%. Analysis of the SAAQ files' entire sample of 5024 drivers showed that drivers suffering from CVD were less likely to be involved in MVCs (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.67 to 0.99) than drivers without CVD. Although the estimate of risk remains unchanged when adjusted for age, it becomes statistically insignificant. It also remains unchanged and statistically insignificant when adjusted for yearly distance driven and driver behaviour, as shown by responses to the questionnaire. Drivers suffering from CVD drove significantly less each year (8900 km) than drivers without medical conditions (13,000 km).
Conclusion: This study shows no increased risk of motor vehicle crashes for drivers suffering from CVD.