Oral and Maxillofacial Surgery Residents’ Understanding of Biostatistics

Objectives: The purpose of this study was to evaluate residents’ understanding of biostatistics and interpretation of research results.

Methods: A questionnaire previously used with internal medicine residents was modified to include oral and maxillofacial surgery examples. An invitation to the internet survey was sent out to all 106 program directors in the United States who were requested to forward the request to their residents. Overall, 112 interns and residents responded (approximately 11% of the population).

Results: The following percentages of interns and residents had taken a course in epidemiology (53%), biostatistics (49%), evidence-based dentistry (65%). Conversely, 10% of OMFS residents had taken none of these classes. Across the six-item test of knowledge of statistical methods, the average percentage correct was 38% (SD 22%). Nearly half (42%) could not correctly identify continuous, ordinal, or nominal variables. Only 21% correctly identified a case-control study, but 79% correctly identified that the purpose of blinding was to reduce bias. Only 46% correctly interpreted a clinically unimportant and statistically non-significant result. In each case OFMS resident knowledge was below that of internal medicine residents (P<.001). None of the demographic or experience factors of OMFS residents was related to statistical knowledge. Although overall a resident’s confidence is correlated with statistical knowledge (r=0.33, P>.001), there was little relationship between a residents’ confidence in correctly interpreting a p-value and whether they actually did a correct interpretation (P >.07).

Conclusions: OMFS residents lack the knowledge in biostatistics and the interpretation of research and are thus unprepared to interpret the results of published clinical research data. Residency programs should include effective biostatistical training in their curricula to prepare residents for evidence-based practice.