Knowledge of European orthodontic postgraduate students on biostatistics.

The purpose of this study was to explore the level of knowledge in biostatistics of orthodontic postgraduate students. A four-section questionnaire, which included a knowledge test/quiz on biostatistics and epidemiology, was developed. This questionnaire was distributed to postgraduate programme directors of European universities to be delivered to students for completion under mock examination conditions (in-class session). The frequency distributions of demographic characteristics were examined, the percentages of participants who agreed or strongly agreed with each attitudinal statement were calculated, and the percentages of participants who felt fairly to highly confident for each statement were determined. Knowledge scores were calculated by the percentage of correct answers; missing values were counted as incorrect answers. The Student's t-test or one-way analysis of variance, where appropriate, was utilized to determine the participants' characteristics associated with mean knowledge scores. Data were further analysed with multiple linear regression modelling to determine the adjusted/unconfounded effect of possible knowledge score predictors. A two-tailed P-value of 0.05 was considered statistically significant with a 95 percent confidence interval (CI). One hundred and twenty seven from a total of 129 orthodontic students who replied completed the questionnaire. The mean correct answers of the participants were 43.8 percent with a 95 percent CI of 40.2-47.3 percent. This score was not influenced by gender, years elapsed from graduation, other advanced degree, or year of study; the sole parameter, which seemed to influence this score was attendance at a biostatistics/epidemiology course (51.9 versus 39.5 percent score of participants who had previously taken a course versus those who had not, P<0.001). A surprising finding was the inability of the responders to identify the appropriate use of the chi-square test (11.8 percent, 95 percent CI: 6.1-17.5 percent). The knowledge on biostatistics of orthodontic postgraduate students in Europe is only influenced by previous relevant education.