Decisions about access to safer, more expensive nonsteroidal anti- inflammatory drugs (NSAIDs) depended on the cost-differential between agents, the relative safety of available agents, and the patients' ulcer risk. The model estimated that, for chronic NSAID users at average risk, unrestricted use of safer NSAIDs has the potential to decrease ulcer-related adverse events at an incremental cost that approximates to other published values. The sensitivity analyses revealed that, given the current differences in acquisition price, under no circumstances would the unrestricted use of a safer agent generate cost-savings in this average-risk population.