Gastrointestinal Bleeding Rates Among Managed Care Patients Newly Started on COX-2 Inhibitors or Nonselective NSAIDs

Abstract

OBJECTIVES:

While cyclooxygenase-2 (COX-2) inhibitors were introduced to the U.S. market with the promise of less gastrointestinal (GI) toxicity than nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), additional research is needed to examine this outcome in the naturalistic setting. The objective of this study was to examine whether use of COX-2 inhibitors is associated with reduced risk of GI bleed in a managed care population.

METHODS:

Adult patients in a multistate managed care organization that were initiated on a nonselective NSAID between January 1999 and August 2002 were identified and matched using propensity scoring with patients in the same managed care organization that were initiated on a COX-2 inhibitor. Matching variables included age, gender, geographical state, comorbidity index, corticosteroid use, warfarin use, arthritis indication, and history of recent GI bleed. Patients were followed until they switched or discontinued their NSAID or COX-2 inhibitor, disenrolled from the health plan, developed a GI bleed, or reached the end of the 1-year follow-up period. A GI bleed was defined as an inpatient hospitalization for GI bleed or at least 2 medical claims with a primary diagnosis for GI bleed. The relative risk (RR) of GI bleed was calculated using proportional hazards regression.

RESULTS:

Overall, 35,007 pairs of COX-2 inhibitor and nonselective NSAID users were evaluated. Mean age was 63 years, and 65% were female. There were 375 cases of GI bleed among 19,201 follow-up years for COX-2 users (19.5 cases per 1,000 person-years) versus 228 cases of GI bleed among 12,680 follow-up years for NSAID users (18.0 cases per 1,000 person-years). The risk of GI bleed was not significantly different for COX-2 users compared with nonselective NSAID users (RR 1.07; 95% confidence interval [CI], 0.90-1.26). Even among high-risk patients, there was no reduction in the risk of a GI bleed among users of COX-2 inhibitors (RR 0.995; 95% CI, 0.84 -1.19).

CONCLUSIONS:

Overall, within this managed care population, COX-2 inhibitor users did not have a reduced risk of a GI bleed compared with patients with similar baseline characteristics using nonselective NSAIDs.