Publication Date: 
Sunday, July 12, 2009

The Problem: Medical injuries are widely recognized as one of the top ten leading causes of mortality in the United States. In 2000, the Institute of Medicine found that between 44,000 and 98,000 Americans die each year from avoidable medical errors. Institute of Medicine. More recent research suggests that more than 13% of hospitalized patients suffer an adverse event resulting in serious harm and that 44% of those events are preventable. The cost of these preventable harms is huge surpassing hundreds of millions of dollars each month.Department of Health and Human Services, Office of the Inspector General. One factor that has attracted attention as a plausible cause of medical error is long work hours for healthcare workers and especially resident physicians. In is not uncommon for residents and other emergency room physicians to work in excess of 100 hours a week. Such shifts raise questions about the influence of fatigue on medical decision-making.

The Law: Medical care in United States is regulated primarily at the state level through professional organizations. Most regulation of work hours has been by state law. New York, for example, limited medical resident work hours in 1989 through regulations (NY Comp Codes R & Reg. Title 10 § 405 (1989)) often referred to as the Libby Zion law in honor of a child whose death was attributed to alleged mistakes by an overworked medical resident. Educational accreditation bodies, like the Accreditation Council for Graduate Medical Education (ACGME), also set requirements for residency programs. In 2003, for example, ACGME limited to 80 the number of hours that residents could work per week on average over a four week period. Report of the ACGME Work Group on Resident Duty Hours. These restrictions do not apply to health care workers that are not medical residents.

The Evidence: Fletcher et al conducted a systematic review of studies evaluating the effectiveness of restrictions on HCW work hours aimed at improving patient care. Fletcher et al, Systematic Review: Effects of Resident Work Hours on Patient Safety, Ann Intern Med. 2004;141:851-857. The reviewers identified seven studies that met their inclusion criteria. The results of the studies were inconsistent across a number of measures and none provided statistically significant evidence that patient outcomes improved subsequent to limitation of healthcare worker hours. The reviewers note that while experimental and bio-psychosocial evidence supports a positive causal relationship between fatigue and diminished performance by healthcare workers, patient outcomes are also influenced by continuity of care. The reviewed studies provide some evidence that the benefits of reduced fatigue are offset by disruption in the care that healthcare workers provide due to the shortening of shifts. Overall, the reviewers did not find conclusive evidence supporting the effectiveness of laws limiting work hours as means of improving patient outcomes.    

The Bottom Line: According to the authors of a peer-reviewed systematic review, there is insufficient evidence to currently support the effectiveness of restrictions on healthcare worker hours in improving patient outcomes.

Impact: Uncertain