Person:

Landrigan, Christopher

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.

Context: Few data exist on the relationships between experienced physicians' work hours and sleep, and patient safety.

Objective: To determine if sleep opportunities for attending surgeons and obstetricians/gynecologists are associated with the risk of complications.

Design, setting, and patients: Matched retrospective cohort study of procedures performed from January 1999 through June 2008 by attending physicians (86 surgeons and 134 obstetricians/gynecologists) who had been in the hospital performing another procedure involving adult patients for at least part of the preceding night (12 am-6 am, postnighttime procedures). Sleep opportunity was calculated as the time between end of the overnight procedure and start of the first procedure the following day. Matched control procedures included as many as 5 procedures of the same type performed by the same physician on days without preceding overnight procedures. Complications were identified and classified by a blinded 3-step process that included administrative screening, medical record reviews, and clinician ratings.

Main outcome measures: Rates of complications in postnighttime procedures as compared with controls; rates of complications in postnighttime procedures among physicians with more than 6-hour sleep opportunities vs those with sleep opportunities of 6 hours or less.

Results: A total of 919 surgical and 957 obstetrical postnighttime procedures were matched with 3552 and 3945 control procedures, respectively. Complications occurred in 101 postnighttime procedures (5.4%) and 365 control procedures (4.9%) (odds ratio, 1.09; 95% confidence interval [CI], 0.84-1.41). Complications occurred in 82 of 1317 postnighttime procedures with sleep opportunities of 6 hours or less (6.2%) vs 19 of 559 postnighttime procedures with sleep opportunities of more than 6 hours (3.4%) (odds ratio, 1.72; 95% CI, 1.02-2.89). Postnighttime procedures completed after working more than 12 hours (n = 958) compared with 12 hours or less (n = 918) had nonsignificantly higher complication rates (6.5% vs 4.3%; odds ratio, 1.47; 95% CI, 0.96-2.27).

Conclusion: Overall, procedures performed the day after attending physicians worked overnight were not associated with significantly increased complication rates, although there was an increased rate of complications among postnighttime surgical procedures performed by physicians with sleep opportunities of less than 6 hours.