Association between funding source and study outcome in orthopaedic research

The current report tests the hypotheses that commercial funding, country of origin, and presence of a coinvestigator with training in statistics are related to the likelihood of a published orthopaedic study arriving at a positive conclusion. All articles from the Journal of Bone and Joint Surgery (American), the Journal of Arthroplasty, and the American Journal of Sports Medicine published in 1 year were reviewed. The blinded review process classified each article as to study design and outcome (positive or negative), according to previously published definitions. Commercial funding was significantly associated with a positive outcome; 78.9% of commercially funded studies concluded with a positive outcome, compared with 63.3% of nonfunded studies. The presence of a statistician or epidemiologist as a coinvestigator, and the place of origin of the study were not associated with outcome. Only 21% of published studies were prospective, 3.5% were randomized, and 10.5% stated an experimental hypothesis; these factors were not associated with study outcome. Published studies that received funding from commercial parties were significantly more likely to report a positive outcome than studies that received no such funding. This does not imply the presence of a corrupting or causative influence of industry sponsorship on research outcomes; additional research is needed to determine whether such nonscientific factors actually affect study outcome or likelihood of publication.