Extended Work Duration
and the Risk of Self-reported
Percutaneous Injuries in Interns
Najib T. Ayas, MD, MPH
Laura K. Barger, PhD
Brian E. Cade, MS
Dean M. Hashimoto, JD, MD
Bernard Rosner, PhD
John W. Cronin, MD
Frank E. Speizer, MD
Charles A. Czeisler, PhD, MD
ing. These injuries may result in the
transmission of blood-borne patho-
gens, including hepatitis and human
immunodeficiency viruses, and thus
occurrence of these percutaneous in-
well studied. We hypothesized that
sleep deprivation may play a role in
Polysomnographic recordings of
interns (residents in their first post-
graduate year) have revealed that sleep
deprivation induced by repeated ex-
tended-duration (?24 hours) work
ures during critical care unit rota-
tions.3,4Among interns scheduled to
XPOSURES TO CONTAMINATED
fluids from percutaneous
needlesticks and laceration in-
juries are serious hazards asso-
Author Affiliations: Division of Sleep Medicine (Drs
Ayas, Barger, Cronin, and Czeisler and Mr Cade) and
Channing Laboratory (Drs Hashimoto, Rosner, and
en’s Hospital, Harvard Medical School, Boston, Mass;
Harvard Work Hours, Health and Safety Group, Di-
the Sleep Disorders Program, University of British
Columbia; Department of Medicine, Vancouver Gen-
Evaluation, Vancouver Coastal Health Research Insti-
tute, Vancouver, British Columbia (Dr Ayas).
Division of Sleep Medicine, Department of Medi-
cine, Brigham and Women’s Hospital, Harvard Medi-
cal School, 221 Longwood Ave, Boston, MA 02115
Context In their first year of postgraduate training, interns commonly work shifts
that are longer than 24 hours. Extended-duration work shifts are associated with in-
creased risks of automobile crash, particularly during a commute from work. Interns
may be at risk for other occupation-related injuries.
Objective To assess the relationship between extended work duration and rates of
percutaneous injuries in a diverse population of interns in the United States.
Design, Setting, and Participants National prospective cohort study of 2737 of
the estimated 18447 interns in US postgraduate residency programs from July 2002
through May 2003. Each month, comprehensive Web-based surveys that asked about
work schedules and the occurrence of percutaneous injuries in the previous month
were sent to all participants. Case-crossover within-subjects analyses were per-
Main Outcome Measures Comparisons of rates of percutaneous injuries during
day work (6:30 AM to 5:30 PM) after working overnight (extended work) vs day work
that was not preceded by working overnight (nonextended work). We also compared
injuries during the nighttime (11:30 PM to 7:30 AM) vs the daytime (7:30 AM to
Results From a total of 17003 monthly surveys, 498 percutaneous injuries were re-
ported (0.029/intern-month). In 448 injuries, at least 1 contributing factor was re-
ported. Lapse in concentration and fatigue were the 2 most commonly reported con-
tributing factors (64% and 31% of injuries, respectively). Percutaneous injuries were
more frequent during extended work compared with nonextended work (1.31/1000
opportunities vs 0.76/1000 opportunities, respectively; odds ratio [OR], 1.61; 95%
confidence interval [CI], 1.46-1.78). Extended work injuries occurred after a mean of
29.1 consecutive work hours; nonextended work injuries occurred after a mean of 6.1
consecutive work hours. Injuries were more frequent during the nighttime than dur-
ing the daytime (1.48/1000 opportunities vs 0.70/1000 opportunities, respectively;
OR, 2.04; 95% CI, 1.98-2.11).
Conclusion Extended work duration and night work were associated with an in-
creased risk of percutaneous injuries in this study population of physicians during their
first year of clinical training.
See also pp 1049, 1063, 1071, and
©2006 American Medical Association. All rights reserved.
(Reprinted) JAMA, September 6, 2006—Vol 296, No. 9
at RABIN MEDICAL CENTER, on March 7, 2007 www.jama.comDownloaded from
Czeisler is the incumbent of an endowed professor-
Since 1985, Dr Czeisler has served as an expert wit-
ness on various legal cases related to sleep and/or cir-
pert witness for a commercial research sponsor.
Funding/Support: This study was supported by grants
vention (1 R01 OH07567) and by the Agency for
Healthcare Research and Quality (R01 HS12032),
Brigham and Women’s Hospital and Division of Sleep
Medicine, Harvard Medical School. Dr Cronin was the
the recipients of National Heart, Lung, and Blood In-
stitute fellowships in the program of training in Sleep,
is supported by NASA Cooperative Agreement NCC
9-58 with the National Space Biomedical Research In-
stitute and by the Air Force Office of Scientific Re-
search. Dr Ayas is supported by a New Investigator
British Columbia Lung Association, a Michael Smith
Award from the University of British Columbia.
Role of the Sponsor: The funding sources had no role
in the design and conduct of the study; collection,
management, analysis, and interpretation of the
data; or preparation, review, or approval of the
Acknowledgment: We would like to thank the Na-
tional Residency Matching Program and the Associa-
tion of American Medical Colleges, especially Jordan
J. Cohen, MD, Paul Jolly, PhD, and the Division of
Medical School Services and Studies, for their assis-
tance with recruitment; DeWitt C. Baldwin, MD, and
Steven R. Daugherty, PhD, for serving as paid con-
sultants to assist in designing the questionnaires; Tim
Ayas, MD, and Sharlene Hudson, MD, for question-
naire review; Steven W. Lockley, PhD, for assistance
with study design; Christopher P. Landrigan, MD,
MPH, for helpful comments on the manuscript; and
Joseph B. Martin, MD, PhD, Anthony Whittemore,
couragement of this work. We are also appreciative
ees at Pearson NCS (company contracted to admin-
mitment to this project.
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EXTENDED WORK DURATION AND RISK OF SELF-REPORTED PERCUTANEOUS INJURIES IN INTERNS
JAMA, September 6, 2006—Vol 296, No. 9 (Reprinted)
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