About the Authors

Laura K Barger

Affiliations Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States of America , Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, United States of America

Najib T Ayas

Affiliations Sleep Disorders Program, University of British Columbia, Vancouver, British Columbia, Canada , Department of Medicine, Vancouver General Hospital, Vancouver, British Columbia, Canada , Center for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada

Brian E Cade

Affiliation Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States of America

John W Cronin

Affiliations Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States of America , Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, United States of America

Bernard Rosner

Affiliation Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Massachusetts, United States of America

Frank E Speizer

Affiliation Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Massachusetts, United States of America

Charles A Czeisler

To whom correspondence should be addressed. E-mail: caczeisler@hms.harvard.edu

Affiliations Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States of America , Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, United States of America

Competing Interests

BEC is a past consultant for Vanda Pharmaceuticals. CAC, LKB, BR, and FES are paid employees of the Brigham and Women's Hospital, a subsidiary of Partners HealthCare System which employs thousands of interns and residents. CAC has received consulting fees from, or has served as a paid member of, scientific advisory boards for Accelerator, Actelion, the American Physiological Society, Aventis, Avera Pharmaceuticals, Cephalon, Coca-Cola, Hypnion, the NASA Jet Propulsion Laboratory (managed by the California Institute of Technology), the National Center for Sleep Disorders Research (which is part of the National Heart, Lung and Blood Institute), Oxford Biosignals, Pfizer, Morgan Stanley, Sleep Multimedia, the Sleep Research Society (for which CAC has served as president), Respironics, Takeda Pharmaceuticals, Unilever, Vanda Pharmaceuticals, and Warburg-Pincus. CAC owns an equity interest in Hypnion and Vanda Pharmaceuticals. CAC has received lecture fees from the Accreditation Council of Graduate Medical Education (which established the current work-hour standards for interns), the American Academy of Allergy, Asthma and Immunology Program Directors, the Association of University Anesthesiologists, Beth-Israel Deaconess Medical Center, Brown Medical School and affiliated Rhode Island Hospital, Cephalon, Dalhousie University, Harvard University, London Deanery, MPM Capital, Partners HealthCare, Philips Lighting, Sanofi-Aventis, the Smithsonian Institution, Takeda, the Society of Neurological Surgeons, the University of Michigan, the University of Pennsylvania, the University of Pittsburgh, the University of Virginia Medical School, and the University of Wisconsin Medical School. CAC holds a number of process patents in the field of sleep/circadian rhythms (e.g., photic resetting of the human circadian pacemaker), all of which are assigned to the Brigham and Women's Hospital per institutional policy. CAC has also received research prizes with monetary awards from the American Academy of Sleep Medicine, the American Clinical and Climatological Association, the Association for Patient-Oriented Research, the National Institute for Occupational Safety and Health, and the National Sleep Foundation, clinical trial research contracts from Cephalon and Pfizer, an investigator-initiated research grant from Cephalon, and unrestricted research and education funds from Cephalon, Philips Lighting, and the Brigham and Women's Hospital. CAC is the incumbent of an endowed professorship provided to Harvard University by Cephalon. Since 1985, CAC has served as an expert witness on various legal cases related to sleep and/or circadian rhythms, but has never served as an expert witness for a commercial research sponsor or on a matter related to interns or residents.

Author Contributions

LKB, NTA, BEC, FES, and CAC designed the study and survey instruments. LKB and JWC enrolled participants. BEC provided technical design of study database and data management. LKB, NTA, BEC, and BR analyzed the data. LKB, NTA, BEC, JWC, BR, FES, and CAC contributed to writing the paper.