Sleep, activity and fatigue reported by Postgraduate Year 1 residents: a prospective cohort study comparing the effects of night float versus the traditional overnight on-call system.

INTRODUCTION: As the traditional overnight call system was shown to contribute to fatigue, Singapore implemented a shift system in 2014. We aimed to compare activity levels, sleep (using a wrist actigraph), fatigue and professional quality of life between residents working on night float and those on overnight calls.

METHODS: All Postgraduate Year 1 (PGY1) residents at our institution were invited to participate. Participants were required to wear a wrist actigraph for four months and complete two validated surveys (Epworth Sleepiness Scale [ESS] and Professional Quality of Life [ProQOL] scale) once each at the start and end of the study.

RESULTS: 49 residents were recruited. Night float and on-call residents showed a comparable median (range) number of steps (10,061 [1,195-15,923] vs. 10,649 [308-21,910]; p = 0.429), amount of sleep logged (361 [149-630] minutes vs. 380 [175-484] minutes; p = 0.369) and time taken to fall asleep (6 [0-14] minutes vs. 6 [range 0-45] minutes; p = 0.726), respectively. Night float residents had less efficient sleep, with 90.5% having sleep efficiency of over 85% compared to 100% of on-call residents (p = 0.127). More night float residents reported ESS scores > 10 (73.1% vs. 38.5%) and higher burnout scores on ProQOL scale (41.4% vs. 21.4%) at the start of the study. However, this was similar to the end of the study and not statistically significant.

CONCLUSION: Physical activity and amount of sleep were not significantly different between night float and on-call residents. Residents on night float reported comparatively more fatigue and burnout.