The Disadvantages of Normal Circadian Chronotype in Medical Students During the Most Demanding Sections of the Objective Structured Clinical Examination (OSCE)

Background and Objective: Previous studies had examined the effect of learning in young adults with generally worse results in cases with the delayed sleep-wake phase disorder. In this study, the relationship between circadian rhythm preferences and objective structured clinical examination (OSCE) results was examined in medical students. Materials and Methods: This study was conducted during the OSCE for clinical license in medical students who were graduation candidates. The reduced form of the Horne and Ostberg Morningness-Eveningness Questionnaire was used to estimate their circadian chronotype. The OSCE consisted of 12 stations, which evaluated different clinical skills, as well as participant’s medical knowledge. The effect of morningness-eveningness preference of each participant on score was evaluated within each station of OSCE. Results: In total, 78 students participated out of a total of 114 clinically competent candidates (aged 25-34 years) were evaluated. In terms of sex, 56% of the students were girl, who obtained significantly higher grades in three stations (P < 0.05). The grades of students with delayed sleep-wake chronotypes were higher in most of the stations; however, the difference was statistically significant in only one station (P = 0.045), which was the most difficult station of the exam. Nevertheless, the delayed sleep-wake chronotype was associated with excessive daytime sleepiness (P = 0.002). Conclusion: Contrary to other similar studies in medical students, normal circadian chronotype was associated with poorer outcome in the OSCE; which may be explained by unusual student training hours during shifts, and the resultant available time for undisturbed study .