Effect of reducing interns' work hours on serious medical errors in intensive care units.
BACKGROUND
Although sleep deprivation has been shown to impair neurobehavioral performance, few studies have measured its effects on medical errors.


METHODS
We conducted a prospective, randomized study comparing the rates of serious medical errors made by interns while they were working according to a traditional schedule with extended (24 hours or more) work shifts every other shift (an "every third night" call schedule) and while they were working according to an intervention schedule that eliminated extended work shifts and reduced the number of hours worked per week. Incidents were identified by means of a multidisciplinary, four-pronged approach that included direct, continuous observation. Two physicians who were unaware of the interns' schedule assignments independently rated each incident.


RESULTS
During a total of 2203 patient-days involving 634 admissions, interns made 35.9 percent more serious medical errors during the traditional schedule than during the intervention schedule (136.0 vs. 100.1 per 1000 patient-days, P<0.001), including 56.6 percent more nonintercepted serious errors (P<0.001). The total rate of serious errors on the critical care units was 22.0 percent higher during the traditional schedule than during the intervention schedule (193.2 vs. 158.4 per 1000 patient-days, P<0.001). Interns made 20.8 percent more serious medication errors during the traditional schedule than during the intervention schedule (99.7 vs. 82.5 per 1000 patient-days, P=0.03). Interns also made 5.6 times as many serious diagnostic errors during the traditional schedule as during the intervention schedule (18.6 vs. 3.3 per 1000 patient-days, P<0.001).


CONCLUSIONS
Interns made substantially more serious medical errors when they worked frequent shifts of 24 hours or more than when they worked shorter shifts. Eliminating extended work shifts and reducing the number of hours interns work per week can reduce serious medical errors in the intensive care unit.
Landrigan
Christopher P
CP
Division of Sleep Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA. clandrigan@rics.bwh.harvard.edu
Rothschild
Jeffrey M
JM
Cronin
John W
JW
Kaushal
Rainu
R
Burdick
Elisabeth
E
Katz
Joel T
JT
Lilly
Craig M
CM
Stone
Peter H
PH
Lockley
Steven W
SW
Bates
David W
DW
Czeisler
Charles A
CA
D006801:Humans; D007362:Intensive Care Units / Q000458:organization & administration; D007388:Internal Medicine / Q000458:organization & administration; D007396:Internship and Residency / Q000458:organization & administration*; D019300:Medical Errors / Q000517:prevention & control / Q000706:statistics & numerical data*; D010561:Personnel Staffing and Scheduling; D011446:Prospective Studies; D012892:Sleep Deprivation; D014940:Work Schedule Tolerance / Q000502:physiology; D016526:Workload