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.