Level of evidence and conflict of interest disclosure associated with higher citation rates in orthopedics

OBJECTIVE: To identify the scientific and nonscientific factors associated with rates of citation in the orthopedic literature. STUDY DESIGN AND SETTING: All original clinical articles published in three general orthopedics journals between July 2002 and December 2003 were reviewed. Information was collected on variables plausibly related to rates of citation, including scientific and nonscientific factors. The number of citations at 5 years was ascertained and linear regression was used to identify factors associated with rates of citation. RESULTS: In the multivariate analysis, factors associated with increased rates of citation at 5 years were high level of evidence (22.2 citations for level I or II vs. 10.8 citations for level III or IV; P=0.0001), large sample size (18.8 citations for sample size of 100 or more vs. 7.9 citations for sample size of 25 or fewer; P<0.0001), multiple institutions (15.2 citations for two or more centers vs. 11.1 citations for single center; P=0.023), self-reported conflict of interest disclosure involving a nonprofit organization (17.4 citations for nonprofit disclosure vs. 10.6 citations for no disclosure; P=0.027), and self-reported conflict of interest disclosure involving a for-profit company (26.1 citations for for-profit disclosure vs. 10.6 citations for no disclosure; P=0.011). CONCLUSION: High level of evidence, large sample size, representation from multiple institutions, and conflict of interest disclosure are associated with higher rates of citation in orthopedics.