Context: Sleep deprivation is associated with increased risk of serious medical errors and motor vehicle crashes among interns. The Accreditation Council for Graduate Medical Education (ACGME) introduced duty-hour standards in 2003 to reduce work hours.
Objective: To estimate compliance with the ACGME duty-hour standards among interns.
Design, setting, and participants: National prospective cohort study with monthly Web-based survey assessment of intern work and sleep hours using a validated instrument, conducted preimplementation (July 2002 through May 2003) and postimplementation (July 2003 through May 2004) of ACGME standards. Participants were 4015 of the approximately 37 253 interns in US residency programs in all specialties during this time; they completed 29 477 reports of their work and sleep hours.
Main outcome measure: Overall and monthly rates of compliance with the ACGME standards.
Results: Postimplementation, 1068 (83.6%; 95% confidence interval [CI], 81.4%-85.5%) of 1278 of interns reported work hours in violation of the standards during 1 or more months. Working shifts greater than 30 consecutive hours was reported by 67.4% (95% CI, 64.8%-70.0%). Averaged over 4 weeks, 43.0% (95% CI, 40.3%-45.7%) reported working more than 80 hours weekly, and 43.7% (95% CI, 41.0%-46.5%) reported not having 1 day in 7 off work duties. Violations were reported during 3765 (44.0%; 95% CI, 43.0%-45.1%) of the 8553 intern-months assessed postimplementation (including vacation and ambulatory rotations), and during 2660 (61.5%; 95% CI, 60.0%-62.9%) of 4327 intern-months during which interns worked exclusively in inpatient settings. Postimplementation, 29.0% (95% CI, 28.7%-29.7%) of reported work weeks were more than 80 hours per week, 12.1% (95% CI, 11.8%-12.6%) were 90 or more hours per week, and 3.9% (95% CI, 3.7%-4.2%) were 100 or more hours per week. Comparing preimplementation to postimplementation responses, reported mean work duration decreased 5.8% from 70.7 (95% CI, 70.5-70.9) hours to 66.6 (95% CI, 66.3-66.9) hours per week (P<.001), and reported mean sleep duration increased 6.1% (22 minutes) from 5.91 (95% CI, 5.88-5.94) hours to 6.27 (95% CI, 6.23-6.31) hours per night (P<.001). However, reported mean sleep during extended shifts decreased 4.5%, from 2.69 (95% CI, 2.66-2.73) hours to 2.57 (95% CI, 2.52-2.62) hours (P<.001).
Conclusion: In the first year following implementation of the ACGME duty-hour standards, interns commonly reported noncompliance with these requirements.