September 4, 2007

CONTACT: Rick Cushman
(215) 349-5659

Pair of Penn Studies Find Residency Requirements
Have Different Effects on Patient Mortality

(PHILADELPHIA) — Researchers at the University of Pennsylvania School of Medicine have found that new national regulations greatly limiting work hours for physicians-in-training did not lead to increased patient deaths. Critics of the new regulations were concerned that the new regulations could hurt patient care. In order to address issues surrounding sleep deprivation of medical residents, recently implemented regulations required them to work fewer hours, resulting in fewer residents on call at any one time and more patient handoffs due to shorter resident schedules. Analyzing over 8 million patient hospitalizations in the Medicare system and over 300,000 hospitalizations in the United States Veterans Affairs (VA) System, the Penn investigators found that duty hour regulations for medical residents in the VA System significantly improved patient mortality; yet these regulations were not associated with either significant worsening or improvement in mortality for Medicare patients. The studies’ corresponding author Kevin G. Volpp, MD, PhD, Assistant Professor of Medicine and Health Care Systems at the University of Pennsylvania and Core faculty member with the Center for Health Equity Research and Promotion at the Philadelphia Veterans Affairs Medical Center, and Co-Principal Investigator Jeffrey H. Silber, MD, PhD, Professor of Pediatrics at Penn and Director of the Center for Outcomes Research at the Children’s Hospital of Philadelphia report their findings in two studies in the September 5th issue of JAMA.

In 2003 the Accreditation Council for Graduate Medical Education (ACGME) implemented duty hour regulations for all accredited residency programs in response to growing concerns that the high number of deaths in United States hospitals from medical errors could be associated with residents working long hours and amidst mounting scientific evidence linking fatigue and impaired cognitive performance. These restrictions included working no more than 80 hours per week with one day per week free of all duties; no more than 24 continuous hours of work with an additional six hours for education and transfer of care; in-house call no more often than every third night; and at least ten hours off between duty periods.

“What we wanted to determine was whether these new residency regulations were effective in lowering mortality for patients,” said Volpp. “Reducing the long work hours of physicians in training is likely to be beneficial, but a necessary byproduct of this reform has been the increased number of patient handoffs between residents, which could adversely affect continuity of care. We wanted to see if these new regulations, on balance, improved patient outcomes.”

The VA study followed all patients admitted to acute-care VA hospitals from July 1, 2000 to June 30, 2005. The Medicare study followed all patients admitted to acute-care non-federal hospitals during this time period as well.

Both studies focused on medical patients admitted with principle diagnoses of acute myocardial infarction, congestive heart failure, gastrointestinal bleeding, or stroke; or general, orthopedic, or vascular surgery patients. The main outcome measure for both studies was mortality within 30 days of hospital admission.

The duty hours rules were one of the largest efforts ever enacted to reduce errors in teaching hospitals. While there were no significant relative increases or decreases in mortality for either medical or surgical patients in the post-reform years among Medicare patients, the VA system did find some significant relative improvements in mortality rates among medical patients in post-reform year 2. The magnitude of the relative improvements in mortality in post-reform year 2 represented about an 11% improvement in mortality for patients in hospitals in the 75th percentile of teaching intensity as compared to hospitals in the 25th percentile of teaching intensity.

This could have occurred for many possible reasons: to the extent that the reduced work hours succeeded in reducing fatigue the impact would be expected to be greater in VA hospitals, as a higher percentage of VA hospitals are teaching hospitals and residents play a larger role in care delivery in this environment. There may also be differences in staffing models, different balances between the effects of decreased fatigue and worsening continuity, and potentially different unmeasured confounders.

“The positive impact of the duty hours in reducing mortality rates in VA hospitals may be due to VA hospitals being more teaching intensive. In addition residents working in VA hospitals are probably less over-taxed, allowing higher compliance with these regulations. The VA also has better information systems than most non-VA settings which may have mitigated the adverse impacts of worsened continuity of care,” said Volpp.

Neither study found significant improvements or decreases in mortality for surgical patients. It remains unclear why, but one potential explanation is that among surgical patients the worsened continuity of care offset any improvements from decreased fatigue.  

Both studies recommend further assessment of duty hour regulations and carefully designed testing of the impact of future iterations of physician work hour regulations on both clinical and educational outcomes.


PENN Medicine is a $3.5 billion enterprise dedicated to the related missions of medical education, biomedical research, and excellence in patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System.

Penn's School of Medicine is currently ranked #3 in the nation in U.S.News & World Report's survey of top research-oriented medical schools; and, according to most recent data from the National Institutes of Health, received over $379 million in NIH research funds in the 2006 fiscal year. Supporting 1,400 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.

The University of Pennsylvania Health System includes three hospitals — its flagship hospital, the Hospital of the University of Pennsylvania, rated one of the nation’s “Honor Roll” hospitals by U.S.News & World Report; Pennsylvania Hospital, the nation's first hospital; and Penn Presbyterian Medical Center — a faculty practice plan; a primary-care provider network; two multispecialty satellite facilities; and home care and hospice.

This release is available online at