The costs and benefits of a screening program to detect dementia in older drivers.

A Markov model was used to assess the cost-benefit ratios of six strategies of screening older drivers for mental status, beginning at age 65. Probabilities of motor vehicle collisions (MVCs), injuries, and fatalities were obtained from national data. Dementia prevalence, test characteristics, and costs were obtained from the literature. Costs included lost wages, car ownership, alternative transportation, and injuries. Using a relative risk of MVC for those with dementia of 5 and a 5% annual discounting rate, the average cost per driver ranged from $51,600 (no testing) to $58,400 (testing every five years). The benefit was < one day of life gained, and the benefits of screening cost approximately 2.8 million dollars per life-year gained. Increasing the relative risk from 5 to 20 substantially improved the cost-benefit of mental status screening. However, mental status screening of older drivers would also be cost-beneficial if physician referral costs were lowered to $60 per evaluation. The authors conclude that a dementia screening program for older drivers would be cost-beneficial if physician evaluations were limited or their cost lowered to < or = $60.