Study objectives: To compare the examination results of self-reported snoring and nonsnoring medical students
Design: We studied the examination scores obtained by medical students answering a multiple-choice test forming part of their final examinations. The students were asked to classify themselves as "nonsnorers," "occasional snorers," or "frequent snorers," and to state their age, sex, height and weight.
Setting: University Hospital, Erlangen, Germany
Participants: 201 medical students (61% males/39% females; mean age 24.6 +/- 2.1 years; BMI 22.4 +/- 2.5 kg/m2) taking their final examinations in internal medicine.
Measurements and results: Seventy-eight students (38.8%) claimed to be nonsnorers, 99 (49.3%) occasional snorers and 24 (11.9%) frequent snorers. The mean examination scores (adjusted for age, sex, and BMI) were 69.6 +/- 9.9% for the nonsnorers, 65.3 +/- 10.0% for the occasional snorers and 62.0 +/- 8.2% for the frequent snorers (p < 0.0001). 12.8% of the nonsnorers failed the exam, compared with 22.2% of the occasional snorers and 41.7% of the frequent snorers (p < 0.001). Logistic regression analysis showed an association between failing the exam and snoring (p = 0.013), but not between failure and age, BMI, or sex (relative risk for snorers adjusted for age, sex and BMI: 1.26; 95%--CI 1.01-1.57).
Conclusions: In medical students, snoring seems to be associated with an increased risk of failing exams in a dose-response manner, even after controlling for age, sex and BMI. For the present, the mechanisms underlying this association must remain a matter of speculation. Snoring-related sleep fragmentation ("upper airway resistance syndrome") might be a causal factor.