Context Despite increasing awareness about the potential impact of financial
conflicts of interest on biomedical research, no comprehensive synthesis of
the body of evidence relating to financial conflicts of interest has been
Objective To review original, quantitative studies on the extent, impact, and
management of financial conflicts of interest in biomedical research.
Data Sources Studies were identified by searching MEDLINE (January 1980-October 2002),
the Web of Science citation database, references of articles, letters, commentaries,
editorials, and books and by contacting experts.
Study Selection All English-language studies containing original, quantitative data
on financial relationships among industry, scientific investigators, and academic
institutions were included. A total of 1664 citations were screened, 144 potentially
eligible full articles were retrieved, and 37 studies met our inclusion criteria.
Data Extraction One investigator (J.E.B.) extracted data from each of the 37 studies.
The main outcomes were the prevalence of specific types of industry relationships,
the relation between industry sponsorship and study outcome or investigator
behavior, and the process for disclosure, review, and management of financial
conflicts of interest.
Data Synthesis Approximately one fourth of investigators have industry affiliations,
and roughly two thirds of academic institutions hold equity in start-ups that
sponsor research performed at the same institutions. Eight articles, which
together evaluated 1140 original studies, assessed the relation between industry
sponsorship and outcome in original research. Aggregating the results of these
articles showed a statistically significant association between industry sponsorship
and pro-industry conclusions (pooled Mantel-Haenszel odds ratio, 3.60; 95%
confidence interval, 2.63-4.91). Industry sponsorship was also associated
with restrictions on publication and data sharing. The approach to managing
financial conflicts varied substantially across academic institutions and
Conclusions Financial relationships among industry, scientific investigators, and
academic institutions are widespread. Conflicts of interest arising from these
ties can influence biomedical research in important ways.