A randomized trial of a three-hour protected nap period in a medicine training program: sleep, alertness, and patient outcomes.
OBJECTIVE
Protected sleep periods for internal medicine interns have previously resulted in increased amount slept and improved cognitive alertness but required supplemental personnel. The authors evaluated intern and patient outcomes associated with protected nocturnal nap periods of three hours that are personnel neutral.


METHODS
Randomized trial at Philadelphia Veterans Affairs Medical Center (PVAMC) Medical Service and Hospital of the University of Pennsylvania (HUP) Oncology Unit. During 2010-2011, four-week blocks were randomly assigned to a standard intern schedule (extended duty overnight shifts of up to 30 hours), or sequential protected sleep periods (phone sign-out midnight to 3:00 AM [early shift] intern 1; 3:00 to 6:00 AM [late shift] intern 2). Participants wore wrist Actiwatches, completed sleep diaries, and performed daily assessments of behavioral alertness. Between-group comparisons of means and proportions controlled for within-person correlations.


RESULTS
HUP interns had significantly longer sleep durations during both early (2.40 hours) and late (2.44 hours) protected periods compared with controls (1.55 hours, P < .0001). At PVAMC sleep duration was longer only for the late shift group (2.40 versus 1.90 hours, P < .036). Interns assigned to either protected period were significantly less likely to have call nights with no sleep and had fewer attentional lapses on the Psychomotor Vigilance Test. Differences in patient outcomes between standard schedule months versus intervention months were not observed.


CONCLUSIONS
Protected sleep periods of three hours resulted in more sleep during call and reductions in periods of prolonged wakefulness, providing a plausible alternative to 16-hour shifts.
Dr. Shea is professor of medicine-clinician educator and associate dean of medical education research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Dinges is professor of psychology in psychiatry and chief of the division of sleep and chronobiology, department of psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Small is associate professor, department of statistics, The Wharton School, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Basner is assistant professor of sleep and chronobiology in psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Mr. Zhu is assistant director of data analytics, LDI Center for Health Incentives and Behavioral Economics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Ms. Norton is research project manager, CHERP, Philadelphia VA Medical Center, and CHIBE, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Mr. Ecker is a senior information technology project leader, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Ms. Novak was research coordinator, CHERP, Philadelphia VA Medical Center, and CHIBE, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, at the time this study was conducted. Currently she is a second-year medical student, Temple University School of Medicine, Philadelphia, Pennsylvania. Dr. Bellini is professor of medicine, and vice chair for education, department of medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Dine is assistant professor of medicine, division of pulmonary and critical care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Dr. Mollicone is president and CEO of Pulsar Informatics, Inc., Philadelphia, Pennsylvania. Dr. Volpp is staff ph
Judy A
JA
Shea
David F
DF
Dinges
Dylan S
DS
Small
Mathias
M
Basner
Jingsan
J
Zhu
Laurie
L
Norton
Adrian J
AJ
Ecker
Cristina
C
Novak
Lisa M
LM
Bellini
C Jessica
CJ
Dine
Daniel J
DJ
Mollicone
Kevin G
KG
Volpp
D056044:Actigraphy; D000328:Adult; D001288:Attention; D005260:Female; D006801:Humans; D007388:Internal Medicine / Q000193:education*; D007396:Internship and Residency / Q000379:methods*; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D010561:Personnel Staffing and Scheduling; D012890:Sleep; D012892:Sleep Deprivation / Q000517:prevention & control*; D016896:Treatment Outcome; D014851:Wakefulness; D014940:Work Schedule Tolerance