Study Objectives:
To explore the effect of sleep loss on cognitive function,
memory, and vigilance in resident physicians and nonphysicians and
on residents’ clinical performance.
Design:
Meta-analysis of 60 studies on the effect of sleep deprivation,
with a total sample of 959 physicians and 1,028 nonphysicians and 5,295
individual effect indexes.
Outcome Measures:
Cognitive performance and performance on clinical
tasks under acute and partial chronic sleep deprivation. Additional analyses
stratified the data by physician/nonphysician, type of performance,
and length and type of sleep loss and assessed the combined effect of
several of these factors.
Results:
Sleep loss of less than 30 hours reduced physicians’ overall performance
by nearly 1 standard deviation and clinical performance by more
than 1.5 standard deviations. The effect of sleep deprivation was larger in
nonphysicians than in physicians (corrected d value -.995 vs -.880), with
these smaller effects likely resulting from “study factors,” primarily variation
in the hours without sleep prior and chronically reduced sleep in the
“rested” controls in physician studies.
Conclusions:
The weekly hours and continuous wakefulness permitted
under the current national minimum standards for residents may not completely
guard against the negative effect of sleep loss on cognitive and
clinical performance. Research is needed to explore the effect of continuous
duty periods and chronic partial sleep loss in residents and to assess
the clinical and educational consequences of sleep loss. The goal should
be to combine scientifically based duty-hour limits with broader efforts to
enhance patient safety and resident learning.