Industry Sponsorship and Authorship of Clinical Trials Over 20 Years

BACKGROUND The pharmaceutical industry has become a major source of funding for biomedical research. Our general observation is that pharmaceutical industry employees are appearing with increasing frequency as coauthors of clinical trial publications. OBJECTIVE To characterize clinical trial funding, reporting, and sources; investigate author—industry affiliation; and describe clinical outcome trends over time. METHODS We reviewed 500 randomly selected clinical trials published in 5 influential medical journals over a 20-year period (1981–2000). RESULTS Of the 500 clinical trials reviewed, 181 (36%) involved pharmaceutical industry as an independent (n = 104) or joint (n = 77) sponsor and 180 (36%) involved a peer-review funding source; the balance (139; 28%) lacked any declared sponsorship. The percentage of industry-sponsored clinical trials increased to 62% during 1997–2000. The percentage of nonprofit sponsored clinical trials remained constant over time, while the percentage of those without funding declaration declined. Reported author affiliation with industry increased to 66% of clinical trials sponsored only by industry. An increase in the percentage of clinical trials with reported author—industry affiliation was observed for all journals. Regardless of funding source, the majority of clinical trials reported clinical outcomes that favored the study drug. CONCLUSIONS Pharmaceutical industry—sponsored and mixed-funding clinical trials are common, and the relative incidence of published trials with these declared funding sources in the 5 journals reviewed has increased. Industry employees are appearing as coauthors of clinical trial publications with increasing frequency.