Objective: to evaluate, with a preliminarystudy, the distribution of circadian rhythms, sleepschedule patterns and their relationship withacademic performance on medical students.Methodology: in this descriptive study, a 10 itemoriginal questionnaire about sleep rhythms andacademic performance was applied to medicalstudents from different semesters. Week (classtime) and weekend schedules, preferences,daytime somnolence and academic performancewere asked. Three chronotypes (morningness,intermediate and eveningness) were definedamong waking-sleeping preference, difficulty tosleep early, exam preparation preference hour and real sleep schedule. The sleep hour deficit perweek night was also calculated. Results: Of the318 medical students that answered the questionnaire,62.6% corresponded to intermediatechronotypes, 8.8% to evening-type and 28.7%to morning-type. Significant difference wasfound among the two chronotype tails (p=0.000,Chi-square 31.13). No correlation was foundbetween academic performance and age, sex,chronotype, week sleep deficit and sleep hours inweek and weekends. A 71.1% of the students slept 6 or fewer hours during class time and 78% hada sleep deficit (more frequent in the eveningchronotype). Conclusions: No relation was foundbetween sleep chronotype and academic performance.Students tend to morningness. Fewstudies have been made on equatorial zones orwithout seasons.Key words: sleep, circadian rhythm, chronobiology,chronotype, academic performance,medical students, medical education, Bogotá,Colombia
