What factors affect the quality of medical students’ doctoral theses? A comparative study in affiliated hospitals of a Chinese university

Background: The quality of doctoral theses decides whether medical PhD and MD candidates could get their doctoral degree successfully. Good quality theses could be rewarded by Peking University which is a great honor for both doctoral candidates and for mentors. The present study aims to determine factors affecting the quality of medical doctoral theses. Methods: Honored theses and nonhonored theses were matched 1:3 randomly by specialty and submission year. Conditional logistic regressions were utilized. Results: Five domains comprising 17 indicators were put forward to evaluate the quality of doctoral theses. 41 honored theses and 119 matched nonhonored theses from years 2012–2016 were analyzed by univariate and multivariate conditional logistic regression. Degree type (OR: 107.56, 95%CI: 1.20–9632.70, P=0.041), first author impact factor (OR:1.24, 95%CI: 1.01–1.53, P=0.040) and correctly reported statistic results (OR: 43.18, 95%CI: 1.88–991.61, P=0.019) are independent factors influencing the quality of a doctoral thesis. Conclusions: The present study indicates that there is a significant gap between PhD and MD students on quality of thesis. The rewarded theses have a feature of high first author impact factor. However, most medical students need more training on statistics to improve the quality of their doctoral theses.