Steps/day And Sleep Time During Night-float Rotations Among Resident Physicians In Puerto Rico

Medical residency involves a specialized training in a hospital setting where physicians are required to float between daytime and night-time rotations. Night-time rotations have been associated with negative physical and emotional states likely related to changes in health-related behaviors such as sleep time and physical activity; which ultimately could impact patient care. PURPOSE: To test the association between sleep time and steps/day during night-time rotation among resident physicians in Puerto Rico. METHODS: A group of 16 resident physicians (8 females, 8 males) wore a GT3X + -BT accelerometer in the non-dominant wrist for 24 h/day during 7-days for 3 weeks (Week1: day-to-night-time float, Week2: night-time float, Week3: night-to-day-time float), recorded the time they went to sleep and woke up every day, and completed measurements of height and weight. ANOVAs were conducted to detect differences by sex and week, and correlation and regression analyses to test associations between sleep and steps/day. RESULTS: No age difference by sex was observed (mean group age = 27.3 ± 1.0 years), and males had higher BMI than females (29.5 ± 3.8 vs. 24.4 ± 2.9 kg/m2, p = 0.01). Sleep time and number of awakenings after sleep onset were not different by sex or week (group sleep time: 5.3 ± 0.9, 6.0 ± 1.5, 6.9 ± 2.9 h/day; 46 ± 16, 51 ± 29, 46 ± 30 times, respectively, P > 0.05). Steps/day were not different by sex during each week; however, steps significantly reduced from 9,883 ± 1,758 to 8,942 ± 1,723 from Week1 to Week2 (p = 0.01). A tendency for an inverse correlation between sleep time and steps/day was observed during each week (r = -0.26, p = 0.06; r = -0.28, p = 0.08; r = -0.51, p = 0.05). CONCLUSIONS: Night-time and transitions from night-to-day-time rotations and vice versa did not appear to influence sleep characteristics; however, resident physicians had less than ideal sleep time and too many awakenings after sleep onset during each week. Walking behavior was reduced during the night-time rotation week; however, steps/day were within the lower range observed among adults. The tendency for more steps/day with less sleep time was unexpected and needs further analysis. Supported in part by the National Institute of General Medical Sciences (NIGMS) National Institutes of Health (Award Number U54GM133807)