Publication productivity and academic rank in medicine: A systematic review and meta-analysis

Purpose Academic medical faculty members are assessed on their research productivity for hiring, promotion, grant, and award decisions. The current work systematically reviews, synthesizes, and analyzes the available literature on publication productivity by academic rank across medical specialties. Method The authors searched PubMed for medical literature, including observational studies, published in English from 2005 to 2018, using the term "h-index," on July 1, 2018. Studies had to report on h-indices for faculty in academic medicine and, if available, other publication metrics, including number of citations, number of publications, and m-indices, stratified by academic rank. The DerSimonian and Laird method was used to perform meta-analyses for the primary (h-index) and secondary (m-index) outcome measures. Results The systematic review included 21 studies. The meta-analysis included 19 studies and data on 14,567 academic physicians. Both h- and m-indices increased with academic rank. The weighted random effects summary effect sizes for mean h-indices were 5.22 (95% confidence interval [CI]: 4.21-6.23, n = 6,609) for assistant professors, 11.22 (95% CI: 9.65-12.78, n = 3,508) for associate professors, 20.77 (95% CI: 17.94-23.60, n = 3,626) for full professors, and 22.08 (95% CI: 17.73-26.44, n = 816) for department chairs. Mean m-indices were 0.53 (95% CI: 0.40-0.65, n = 1,653) for assistant professors, 0.72 (95% CI: 0.58-0.85, n = 883) for associate professors, 0.99 (95% CI: 0.75-1.22, n = 854) for full professors, and 1.16 (95% CI: 0.81-1.51, n = 195) for department chairs. Conclusions Both h- and m-indices increase with successive academic rank. There are unique distributions of these metrics among medical specialties. The h- and m-indices should be used in conjunction with other measures of academic success to evaluate faculty members for hiring, promotion, grant, and award decisions.