Bias towards publishing positive results in orthopedic and general surgery: a patient safety issue?

Background: Research articles reporting positive findings in the fields of orthopedic and general surgery appear to be represented at a considerably higher prevalence in the peer-reviewed literature, compared to published studies on negative or neutral data. This publication bias may alter the balance of the available evidence-based literature and may affect patient safety in surgery by depriving important information from unpublished negative studies. Methods: A comprehensive review of all published articles in a defined 7-year period was performed in 12 representative journals in the fields of orthopedic and general surgery. Every article published in all volumes of these journals between January 2000 and December 2006 was reviewed and rated by three investigators. Rating of articles was performed according to a uniform, standardized algorithm. All original articles were stratified into positive, negative or neutral, depending on the reported results. All non-original papers were excluded from analysis. Results: A total of 30,197 publications were reviewed over a 7-year time-period. After excluding all non-original articles, a total of 16,397 original papers were included in the final analysis. Of these, 12,251 (74%) articles were found to report positive findings, 2,709 (17%) reported negative results, and 1,437 (9%) were neutral. A similar publication pattern was found among all years and all journals analyzed. Altogether, 91% of all original papers reported significant data (positive or negative), whereas only 9% were neutral studies that did not report any significant findings. Conclusion: There is a disproportionately high number of articles reporting positive results published in the surgical literature. A bias towards publishing positive data will systematically overestimate the clinical relevance of treatment effects by disregarding important information derived from unpublished negative studies. This publication bias remains an area of concern and may affect the quality of care of patients undergoing surgical procedures.