AN ARTICLE in the February 2000 issue of JAMA concluded that annual retinal screening for many individuals with type 2 diabetes mellitus may not be warranted on grounds of cost-effectiveness. Vijan et al1 reported that, compared with biannual screening, annual retinopathy screening for low-risk patients with diabetes costs more than $100 000 for each additional quality-adjusted life year (QALY) gained. The results of a study published in the March 2000 issue of the New England Journal of Medicine concluded that extending hospital stays beyond 4 days for patients with uncomplicated myocardial infarctions was economically unattractive, costing more than $105 000 per QALY gained.2 These studies demonstrate that commonly used interventions may not be worthwhile investments of health care resources. By contrast, a study published in the June 2000 issue of the Annals of Internal Medicine concluded that, compared with no treatment, sildenafil (Viagra) is a cost-effective treatment for erectile dysfunction, producing an incremental QALY for the relatively low cost of $11 000.3 The latter study raises questions about whether many health care insurers were hasty in deciding that they would not add sildenafil to the list of services covered by their health plans.4