Motor vehicle collision injuries and sensory impairments of older drivers.

To determine whether ocular disease, impaired vision, or diminished hearing might increase the risk of motor vehicle collision injuries in older drivers, we conducted a population-based case-control study at a large Health Maintenance Organization (HMO). All study subjects were HMO members who were licensed drivers age 65 or over. Cases were drivers treated for injuries sustained in a police-reported collision that occurred in 1987 or 1988. Controls were drivers who experienced no such injury during the study years and were matched to cases by age, sex, and county of residence. We found no clear evidence that ocular diseases or impaired visual acuity, as customarily recorded in the medical record, increased the risk of an injury collision. Although there was no significant association between impaired hearing and injury collision, we found that subjects who used hearing aids while driving had about twice the risk of others (adjusted RR 2.1; 95% CI 1.2-3.8). We conclude that mild reductions in static visual acuity have little effect on the risk of injury collisions for older drivers. Moreover, the types of vision tests needed to identify elderly drivers at increased risk are not those that are generally administered during routine optometry examinations or at the time of licence renewal. Further research is needed to verify a possible increase in risk among elderly drivers using hearing aids.