Analysis of Medical Student Sleep Metrics using Wrist Actigraphy

Introduction: Sufficient sleep is important for optimal cognitive performance, as well as physical and mental health. Due to the demanding curriculum, medical students are a vulnerable population to sleep-related fatigue and associated poor health outcomes. The adverse health that accompanies poor sleep is concerning as the sleep habits students develop in medical school may continue into their profession. Noting the importance of sleep and the cognitive consequences of insufficient sleep, we chose to objectively measure sleep metrics in medical students using wrist actigraphy over a 2-week period.

Methods: 30 medical students wore a Fatigue Science ReadiBand for 14 days during the Fall 2021 semester. Sleep metrics analyzed include Average Effectiveness (0-100 scale that accurately predicts cognitive alertness), Sleep Quantity (hours), Sleep Quality (1-10 scale based on physiologic measurements), and SAFTE ReadiScore Zones (equivalent to Blood Alcohol Content(BAC) impairment and slowed reaction time). Means and standard deviations were calculated for each class (first-year = 9, second-year = 9, third-year = 8, fourth-year = 4).

Results: Second-year students demonstrated the highest Average Effectiveness (88.78/100 ± 5.19) and Sleep Quality (7.00/10 ± 1.41) scores and spent the most time in the “very low risk” ReadiScore Zone (48.08% ± 33.68; reaction time slowed by 0-5%) compared to other classes. First-year students obtained the highest Sleep Quantity (6.76 hours ± 1.29) yet spent approximately half of their time during the 14- days with reaction time decreased by 18-34%. Third-year students had the lowest Average Effectiveness score (86.63/10 ± 10.16) and Sleep Quantity (6.26 hours ± 1.24), while the fourth-year students had the worst Sleep Quality (6.25/10 ± 1.71). Additionally, third and fourth-year students spent the most time in high-risk ReadiScore Zones, with reaction time slowed by 34-55%. Overall, Sleep Quantity was less than 7 hours per night in each class, Sleep Quality was not greater than 7/10 in any class, and no class spent at least half their time in the highest SAFTE ReadiScore Zone (“very low risk”).

Conclusion: Results indicate that medical students are not obtaining the recommended hours of sleep per night. This may be due to sacrificing sleep for medical school-related demands, such as preparation for upcoming exams and clinical obligations. Second-year students demonstrated the best sleep metrics, possibly due to familiarity with the academic curriculum of medical school. Furthermore, third and fourth-year students showed the worst sleep metrics, likely due to clinical rotations, residency applications, and residency interview preparation.