Optimising sleep and performance during night float: A systematic review of evidence and implications for graduate medical education trainees

J Sleep Res. 2021 Aug;30(4):e13212. doi: 10.1111/jsr.13212. Epub 2020 Oct 15.


Graduate medical education (GME) training commonly requires residents and fellows to engage in night float shift work. This review aims to assess the effectiveness of interventions for trainees when preparing for, completing, and recovering from working night float shifts. We reviewed all available studies published prior to September 2019 using PubMed, Scopus, CINAHL, the Cochrane library, PsycINFO, and Google Scholar databases. We included all original, primary research articles assessing either non-pharmacological or pharmacological interventions on the chronobiological and physiological effects of night float shift work among GME trainees. Five studies (n = 179 patients) met inclusion criteria. Interventions included melatonin in the morning before sleep after night float shifts, napping during night float shifts, modafinil after a night of sleep deprivation, and caffeinated energy drinks after 6 consecutive night float shifts. Melatonin improved one measure of attention. A 2-hr nap was associated with improved speed related to task switching. Modafinil improved performance in tests of cognition. Caffeinated energy drinks led to improvement in select driving performance variables and reaction time. Effect sizes for outcome variables were calculated. Heterogeneity among the studies precluded combining the data in a meta-analysis. According to GRADE criteria, the quality of the evidence in these studies was low or very low. Our findings suggest GME trainees may benefit from utilising a limited number of interventions when preparing for or recovering from night float shift work. More investigation is needed to identify interventions that could help GME trainees adapt to and recover from working night float shifts.

Keywords: ACGME; graduate medical education; night float; night shift; residency; shift work.

Publication types

  • Research Support, N.I.H., Extramural
  • Systematic Review

MeSH terms

  • Adaptation, Physiological / drug effects
  • Attention / drug effects
  • Caffeine / pharmacology
  • Education, Medical, Graduate*
  • Energy Drinks
  • Fatigue / physiopathology
  • Fatigue / prevention & control
  • Humans
  • Melatonin / pharmacology
  • Modafinil / pharmacology
  • Reaction Time / drug effects
  • Sleep / drug effects*
  • Sleep / physiology*
  • Sleep Deprivation / physiopathology*
  • Sleep Disorders, Circadian Rhythm / physiopathology*
  • Sleep Disorders, Circadian Rhythm / prevention & control
  • Work Schedule Tolerance / physiology*
  • Work Schedule Tolerance / psychology*


  • Caffeine
  • Melatonin
  • Modafinil