Poor Quality of Sleep is Associated with Lower Academic Performance in Undergraduate Dental Students: A Cross-Sectional Study

Purpose This study aimed to assess the quality of sleep and associated factors among dental students. Methods All dental students regularly enrolled at the Federal University of Pelotas, Brazil, were invited to participate. A structured online questionnaire was applied to collect the independent variables, including academic performance. Quality of sleep was assessed by the validated version of the Pittsburgh Sleep Quality Index. Sample was dichotomized as good sleep quality (total score: ≤ 4) and at least poor quality (total score: ≥ 5). Adjusted analyses were performed using Poisson regression with robust variance to detect the association between sleep quality and independent variables. Independent adjusted models were performed to the whole-sample, only undergraduate and only graduate dental students. Results Poor quality of sleep was detected in 266 (65.2%) dental students, of which 228 (68.9%) and 38 (49.4%) were undergraduate and graduate dental students, respectively. Female students presented a prevalence ratio (PR) 19% higher compared to males (95% confidence interval [CI] 1.01–1.41). When only graduate students were considering, those that reported not being the head of the family presented a PR 4.39 higher for poor quality of sleep (95% CI 1.91–10.09). Poor quality of sleep was associated with lower academic performance among undergraduate students (PR: 0.94; 95% CI 0.89–0.99), but not significantly associated when graduate students are considered (PR: 0.99; 95% CI 0.96–1.03). Conclusion It was concluded that dental students, mainly female ones, have high prevalence of poor quality of sleep, which is associated with undergraduate student’s worst academic performance.