Assessing the impact of sleep restriction on the attention and executive functions of medical students: a prospective cohort study

OBJECTIVE: To compare the performance of medical students regarding attention and executive functions during a period of sleep restriction (insufficient sleep; period of classes) and a period of free sleep (sufficient sleep; vacation period). BACKGROUND: Sleep deprivation is associated with poor academic outcomes. Few studies have assessed the cognitive changes associated with sleep deprivation due to insufficient sleep syndrome in students and how they occur in real-life situations. METHODS: This was a prospective cohort study. Medical students were assessed at two moments (class and vacation). The interval between assessments was 30 days. The Pittsburgh Sleep Quality Index, the Consensus Sleep Diary, the Montreal Cognitive Assessment, the Psychomotor Vigilance Test (PVT) and the Wisconsin Sorting Cards Test were used. RESULTS: Forty-one students were assessed, 49% were female, with a median age of 21 (20; 23) years. There was a lower number of hours slept (5.75 (5.4; 7.0) vs 7.33 (6.0; 8.0) hours; p = 0.037), and a significantly poorer performance in the PVT (mean reaction time, p = 0.005; Minor lapses, p = 0.009) during the period of classes when compared to the vacation period. There was a correlation between the variation in hours of sleep of the two assessments and a variation in minor lapses in the two assessments (Ro: -0.395; p = 0.011; Spearman's correlation). CONCLUSIONS: Students had fewer hours of sleep and more reduced attention during the period of classes than during the vacation period. This decrease in sleeping hours was correlated with more impaired attention.