Background: To study the relation between reported drug performance in published trials and support of the trials by the manufacturer of the drug under evaluation, we studied a sample of trials of nonsteroidal anti-inflammatory drugs (NSAIDs) used in the treatment of arthritis.
Methods: All randomized control trials of NSAIDs published between September 1987 and May 1990 identified by MEDLINE were reviewed. If an article met the following criteria (n = 61), it was selected: trials involving adult patients with osteoarthritis or rheumatoid arthritis (n = 180), use of nonsalicylate NSAIDs marketed in the United States (n = 101), randomized control trial (n = 81), duration of the trial 4 or more days (n = 78), and use of an efficacy outcome measure (n = 61). Reviewers, "blinded" to manufacturer status, evaluated the narrative interpretation of results and extracted numeric data on efficacy and toxicity. Manufacturer-associated trials were defined as those that acknowledged an association with a pharmaceutical manufacturer. Because of the scarcity of non-manufacturer-associated trials (n = 9), we report only on the manufacturer-associated articles.
Results: Fifty-two publications (85.2%) representing 56 trials were associated with a manufacturer. The manufacturer-associated drug was reported as comparable with (71.4%) or superior to (28.6%) the comparison drug in all 56 trials. These narrative claims of superiority were usually justified with trial data. Of the trials identifying one drug as less toxic (n = 22), the manufacturer-associated drug's safety was reported as superior to the comparison drug in 86.4% of cases. Justification for the narrative interpretation of the trial findings regarding less toxicity was provided in only 12 (54.5%) of 22 trials.
Conclusion: The manufacturer-associated NSAID is almost always reported as being equal or superior in efficacy and toxicity to the comparison drug. These claims of superiority, especially in regard to side effect profiles, are often not supported by trial data. These data raise concerns about selective publication or biased interpretation of results in manufacturer-associated trials.