Effect of reducing interns' weekly work hours on sleep and attentional failures.
BACKGROUND
Knowledge of the physiological effects of extended (24 hours or more) work shifts in postgraduate medical training is limited. We aimed to quantify work hours, sleep, and attentional failures among first-year residents (postgraduate year 1) during a traditional rotation schedule that included extended work shifts and during an intervention schedule that limited scheduled work hours to 16 or fewer consecutive hours.


METHODS
Twenty interns were studied during two three-week rotations in intensive care units, each during both the traditional and the intervention schedule. Subjects completed daily sleep logs that were validated with regular weekly episodes (72 to 96 hours) of continuous polysomnography (r=0.94) and work logs that were validated by means of direct observation by study staff (r=0.98).


RESULTS
Seventeen of 20 interns worked more than 80 hours per week during the traditional schedule (mean, 84.9; range, 74.2 to 92.1). All interns worked less than 80 hours per week during the intervention schedule (mean, 65.4; range, 57.6 to 76.3). On average, interns worked 19.5 hours per week less (P<0.001), slept 5.8 hours per week more (P<0.001), slept more in the 24 hours preceding each working hour (P<0.001), and had less than half the rate of attentional failures while working during on-call nights (P=0.02) on the intervention schedule as compared with the traditional schedule.


CONCLUSIONS
Eliminating interns' extended work shifts in an intensive care unit significantly increased sleep and decreased attentional failures during night work hours.
Lockley
Steven W
SW
Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
Cronin
John W
JW
Evans
Erin E
EE
Cade
Brian E
BE
Lee
Clark J
CJ
Landrigan
Christopher P
CP
Rothschild
Jeffrey M
JM
Katz
Joel T
JT
Lilly
Craig M
CM
Stone
Peter H
PH
Aeschbach
Daniel
D
Czeisler
Charles A
CA
D000328:Adult; D001288:Attention; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000458:organization & administration; D007388:Internal Medicine / Q000458:organization & administration; D007396:Internship and Residency / Q000458:organization & administration*; D008297:Male; D010561:Personnel Staffing and Scheduling; D017286:Polysomnography; D012890:Sleep; D012892:Sleep Deprivation / Q000503:physiopathology; D014940:Work Schedule Tolerance / Q000502:physiology*; D016526:Workload