Level of evidence in Spine compared to other orthopedic journals

Study Design. Two reviewers rated the 112 clinical articles, from January through June 2003, published in Spine using a level-of-evidence grading system. The ratings were compared to previously published ratings of 2 orthopedic journals with similar impact factors. Objective. To compare Spine to other orthopedic journals using a level-of-evidence rating system. Summary of Background Data. A previous study evaluating the levels of evidence in 9 orthopedic journals found a correlation between higher-level studies and journal impact factor. Spine was not included in the analysis. Methods. Studies were designated therapeutic, prognostic, diagnostic, or economic, and their evidence rated as level I, II, III, or IV. Reviewers were blinded to the other's ratings. Results. Ratings were as follows: 43.8% of the Spine articles were therapeutic, 37.5% prognostic, 17.9% diagnostic, and 0.9% economic. Of studies, 16.1% were level I, 22.3% level II, 8.0% level III, and 53.6% level IV. Kappa values for interobserver reliability showed good correlation between reviewers. There was no significant difference among Spine and 2 leading orthopedic journals in their likelihood of publishing level I or II studies. Conclusion. Spine publishes clinical studies with levels of evidence comparable to the 2 orthopedic journals with similar impact factors.