Abstract

The introduction of selective cyclooxygenase-2 (COX-2) inhibitors, a group of NSAIDs, has resulted in arapid increase in the number of people exposed to NSAIDs. Many patients who would otherwise not have used an NSAID are now using COX-2 inhibitors without a corre-sponding decrease in the use of more traditional nonselec-tive NSAIDs.1,2 Although COX-2 inhibitors have been found to be associated with a lower risk of significant adverse gas-trointestinal events than have traditional nonselective NSAIDs at the level of the individual patient,3,4 recent evi-dence suggests that the market expansion created by COX-2 inhibitors may increase rates of hospital admissions be-cause of upper gastrointestinal (GI) bleeding at the popula-tion level.5 The degree of adoption of a new drug into clinical practice is driven, in part, by decisions of public and private insurers to provide coverage. For example, COX-2 inhibitors wer