Evaluation of Conflict of Interest in Economic Analyses of New Drugs Used in Oncology

CONTEXT: Recent studies have found that when investigators have financial relationships with pharmaceutical or product manufacturers, they are less likely to criticize the safety or efficacy of these agents. The effects of health economics research on pharmaceutical company revenue make drug investigations potentially vulnerable to this bias. OBJECTIVE: To determine whether there is an association between pharmaceutical industry sponsorship and economic assessment of oncology drugs. DESIGN: MEDLINE and HealthSTAR databases (1988-1998) were searched for original English-language research articles of cost or cost-effectiveness analyses of 6 oncology drugs in 3 new drug categories (hematopoietic colony-stimulating factors, serotonin antagonist antiemetics, and taxanes), yielding 44 eligible articles. Two investigators independently abstracted each article based on specific criteria. MAIN OUTCOME MEASURE: Relationships between funding source and (1) qualitative cost assessment (favorable, neutral, or unfavorable) and (2) qualitative conclusions that overstated quantitative results. RESULTS: Pharmaceutical company-sponsored studies were less likely than nonprofit-sponsored studies to report unfavorable qualitative conclusions (1/20 5% vs 9/24 38%; P = .04), whereas overstatements of quantitative results were not significantly different in pharmaceutical company-sponsored (6/20 30%) vs nonprofit-sponsored (3/24 13%) studies (P = .26). CONCLUSIONS: Although we did not identify bias in individual studies, these findings indicate that pharmaceutical company sponsorship of economic analyses is associated with reduced likelihood of reporting unfavorable results.