Cost-effectiveness analysis of bicycle helmet subsidies in a defined population

To examine the potential effects of bicycle safety helmet cost subsidy on bicycle head injury rates and costs.

Using empiric data on the incidence and costs of bicycle injuries to children, we examined the hypothetical effects of various bicycle helmet subsidies in a cost-effectiveness analysis. A hypothetical cohort of 100,000 5- through 9-year-olds was followed for 5 years after helmet cost subsidization. Sensitivity analyses were done of three different levels of safety helmet subsidy ($5, $10, $15), three discount rates (2%, 4%, 6%), 10 levels of safety helmet use ranging from 10% to 100%, and the occurrence or nonoccurrence of catastrophic head injuries.

Forty-three children 5 through 9 years of age and 27 children 10 through 14 years of age with head injuries due to bicycling were identified through emergency department surveillance of a population of 29,533.

Group Health Cooperative of Puget Sound, a large health maintenance organization.

Bicycle head injuries prevented and the savings or costs associated with various subsidy, safety helmet use, and discount rates.

Hypothetically, an increase in bicycle helmet use rates to 40% to 50% due to subsidies of $5 or $10 prevents 564 to 840 head injuries in a cohort of 100,000 5- through 9-year-olds over 5 years. Under these conditions and a 2% discount rate, cost savings ranging from $189,207 to $427,808 will result when catastrophic head injuries are included in the analysis.

Subsidization of bicycle safety helmets to achieve a cost of $14 to $20 per helmet and use rates of 40% to 50% will likely prove cost-effective. Empirical evidence from a Seattle campaign suggests that such helmet use rates are achievable.