Use of nonsteroidal anti-inflammatory drugs and gastroprotective agents before the advent of cyclooxygenase-2-selective inhibitors: analysis of a large United States claims database

Abstract

Background: Previous studies have shown that 20% to 40% of patients requiring nonsteroidal anti-inflammatory drugs (NSAIDs) are concomitantly prescribed gastroprotective agents (GPAs) such as proton pump inhibitors (PPIs) and H2-receptor antagonists.

Objective: The purpose of this study was to examine NSAID prescription patterns and the concurrent use of GPAs in a large national sample of patients who were prescribed NSAIDs for the first time.

Methods: Patterns of NSAID use, particularly chronic NSAID use, and of concomitant use of GPAs were examined using a large US-based prescription database. Patients with at least 1 NSAID prescription dispensed between May 1 and August 31, 1998, were identified. Persons with any NSAID prescription within 4 months prior to the first (index) prescription were excluded. The remaining patients were defined as new NSAID users and then classified as chronic users (> or = 30 days of supply of NSAIDs during the 120 days of follow-up after the first NSAID prescription) or acute users (<30 days of NSAID supply during the 120 days of follow-up). Concomitant GPA use was defined as receipt of any GPA prescription between the fill date of NSAID prescription and 125% of days of supply. NSAIDs included diclofenac/misoprostol (in a fixed combination), diclofenac, naproxen, nabumetone, ibuprofen, and "other" (comprising several less frequently prescribed agents). Patients were classified as users of a particular NSAID based on the first NSAID prescription they received. GPAs included PPIs, H2-receptor antagonists, and misoprostol.

Results: A total of 3,028,808 new NSAID users were identified. Chronic NSAID users (47.8% of the sample) were older than acute users. The percentage of new chronic users aged > or = 65 years for each of the NSAIDs was 41.2% for diclofenac/ misoprostol, 33.0% for nabumetone, 30.8% for diclofenac, 20.4% for naproxen, and 20.3% for ibuprofen. The percentage of women was higher among patients treated with diclofenac/misoprostol than among patients treated with all other NSAIDs (P < 0.001). During the 120 days of follow-up, the percentages of NSAID users with concomitant GPA use were 22.7% for diclofenac/misoprostol, 16.3% for diclofenac, 11.5% for naproxen, 18.0% for nabumetone, 12.3% for ibuprofen, and 14.8% for other NSAIDs. Based on days of supply, the rates of concomitant GPA use were 31.1%, 23.6%, 17.6%, 27.3%, 18.8%, and 22.5% for diclofenac/misoprostol, diclofenac, naproxen, nabumetone, ibuprofen, and other NSAID users, respectively. Among those who were taking GPAs before the NSAID index prescription date, -89% continued GPA therapy.

Conclusions: Approximately 22% of the days of NSAID supply were covered by GPAs. Prior GPA use was the strongest predictor of subsequent concomitant GPA/ NSAID use. Differences in GPA use were observed among patients using different NSAIDs.