Background The increasing trend in opioid analgesic (OA) use in older adult drivers has raised concerns about their risk to be involved in car crashes.

Aim To investigate if older adult drivers who recently started using OAs (new users) have a higher probability of being involved in single injurious crashes.

Methods Population-based matched case-control study. Data from population registers were merged using a unique personal identity number. Cases were drivers aged 50–80 years involved in an injurious single crash between 01.07.05 and 31.12.09. Four controls were randomly matched to each case by sex, birth month/year, and area of residence from persons holding a valid driving license and who did not crash. New use was defined as at least one dispensation within 1–30 days prior to the crash date, but none within the previous 31–180 days. Conditional logistic regression was used to estimate ORs adjusting for benzodiazepine use, comorbidity, civil status, and occupation.

Results Adjusted ORs for new use were two-fold that of drivers using 1–2 non-OA medications (OR 2.0; 95% CI: 1.6–2.5).

Conclusion New users of OAs may result in higher crashing risks. Older adults need to be made aware of this initial risk linked to the use of OA.