Hendrik Friederichs
Introduction In medical education research, the transfer of knowledge depends heavily on the visibility of scientific publications. Whether Open Access (OA) actually increases this visibility through a citation advantage (Open Access Citation Advantage, OACA) is still unclear for the field of medical education. This study aims to determine the existence and size of an OACA for medical education articles indexed in PubMed between 2010 and 2019.Method In a retrospective bibliometric cohort study, all entries classified as research articles by iCite® with the MeSH term ‘Medical Education’ (N = 43,275) were analysed. OA was defined by the presence of a PubMed Central identifier (PMCID). Primary endpoints were total citations, citations per year, and the Relative Citation Ratio (RCR). Group comparisons were made using Yuen‑Welch t‑tests (20 % trimmed means, α = 0.05). Sensitivity analyses included negative binomial regression with year and journal fixed effects, and quantile regression for RCR.Results 21.2% of articles had a PMCID. PMCID-indexed publications showed higher trimmed means for total citations (10.31 vs. 7.00), annual citations (1.29 vs. 0.79), and RCR (0.79 vs. 0.49; all p < .001). Robust effect sizes (δˆRAKP, Algina-Keselman-Penfield robust standardized difference) ranged from 0.27 to 0.35 (small to medium). Negative binomial models with year and journal fixed effects confirmed these findings (IRR range: 1.53–1.67).Conclusions PMCID-indexed articles in the field of medical education are cited significantly more frequently and have higher field‑normalised impact values than non‑OA publications. Despite financial hurdles and methodological limitations including potential selection bias, the moderate OACA supports strategically expanding OA publication funds to maximise the reach and impact of medical education research. Prospective studies should consider different OA types, altmetrics, and potential confounders to pinpoint the impacts of OA.