Knowledge of Postgraduate Dental Students on Evidence-based Dentistry and Research Methodology. An International Survey

Purpose: To assess the knowledge of postgraduate dental students about evidence-based methodology pertaining to the design, conduct, and critical appraisal of clinical trials. Materials and Methods: Senior postgraduate students were surveyed from the dental schools of three universities in Athens (Greece), Boston (USA), and Zürich (Switzerland). The proportion of students correctly answering each of the 10 questions of the survey, as well as the cumulative scores, were analysed statistically with descriptive statistics and logistic/linear regression analysis at α = 5%. Results: A total of 96 students with a mean age of 30.0 years attained an overall correct score of 45.6% ± 15.0%, with correct answers to each question ranging from 13.5% to 86.5%. The questions most frequently answered incorrectly pertained to characterising sensitivity/specificity (13.5%), the number needed to treat (14.0%), the credibility of trial synthesis in meta-analysis (23.7%), and publication bias (29.5%). The vast majority of postgraduate students could correctly identify the role of statistical power of a trial (63.8%), random allocation sequence in a randomised trial (76.0%), and blinding in a randomised trial (86.5%). Paediatric dentistry postgraduate students scored better than students from other departments (+15.1%; 95% CI: 3.0% to 27.1%; p = 0.02). Conclusions: Postgraduate students in orthodontics and other dental specialties possessed moderate knowledge on evidence-based methodology and clinical trials. Efforts should be made to integrate such subjects in university postgraduate curricula, so that future dental specialists can critically appraise such research papers. Keywords: clinical trial, educational assessment, epidemiologic research design, evidence-based dentistry, questionnaire, survey, systematic review