Understanding biostatistics: A study of Nigerian dental resident doctors

Background: Central to the process of keeping current with clinical information in dentistry is the ability of a practitioner to evaluate the reliability and validity of current scientific evidence. Pertinent to this is a basic understanding of statistics. The level of understanding of biostatistics has not been reported among Dental resident doctors in Nigeria. Aim: The purpose of this study was to evaluate dental residents' understanding of biostatistics and the interpretation of research results. Materials and Methods: This was a study carried out among dental resident doctors who attended the revision course organized by the Faculty of Dental Surgery, National Postgraduate Medical College of Nigeria in March 2013. A cross-section of dental resident doctors at the Lagos University Teaching Hospital was also included in the study. Data collected through a self-administered questionnaire included demographic characteristics of the residents, their attitudes toward statistics, and their confidence about interpreting and assessing statistical concepts. Residents' knowledge of statistics was also tested by asking some basic statistical questions. Results: Eighty-one respondents completed the questionnaire. About two-third (66.7%) had taken a course in epidemiology; and 60.5% had taken a course in biostatistics. Only a quarter (25.9%) of respondents could correctly identify that lower facial height in centimeters as a continuous variable, and 23.5% thought that centimeters was a nominal measure of facial height. Facial asymmetry classified as none, moderate, severe was correctly identified as an ordinal variable by only a third (35.8%) of the respondents. Two keys to the highest level of evidence in a study are blinding and controls. Sixty-eight percent of the respondents correctly identified that this avoids observer and subject bias. However, only about one-fifth (22.2%) correctly identified that a P > 0.05 (not statistically significant) indicates at least a 1-in-20 chance occurrence. Overall, respondents' knowledge of biostatistics was low, with only 29% of the item answered correctly. Conclusion: Most residents in this study lack the knowledge in biostatistics needed to interpret many of the results in published clinical research. Because clinicians need to have such skills to engage in evidence-based practice, every effort needs to be made to include effective training in biostatistics during undergraduate and residency training programs.