Clinical question: Does the reduction in work hours for residents affect mortality in medical and surgical ICUs?
Background: A reduction in work hours for residents was enforced in July 2003. Several prior studies using administrative or claims data did not show an association of the reduced work hours for residents with mortality in teaching hospitals when compared with nonteaching hospitals.
Study design: Observational retrospective registry cohort.
Setting: Twelve academic, 12 community, and 16 nonteaching hospitals in the U.S.
Synopsis: Data from 230,151 patients were extracted as post-hoc analysis from a voluntary clinical registry that uses a well-validated severity-of-illness scoring system. The exposure was defined as date of admission to ICU within two years before and after the reform. Hospitals were categorized as academic, community with residents, or nonteaching. Sophisticated statistical analyses were performed, including interaction terms for teaching status and time. To test the effect the reduced work hours had on mortality, the mortality trends of academic hospitals and community hospitals with residents were compared with the baseline trend of nonteaching hospitals. After risk adjustments, all hospitals had improved in-hospital and ICU mortality after the reform. None of the statistical improvements were significantly different.
Study limitations include the selection bias, as only highly motivated hospitals participating in the registry were included, and misclassification bias, as not all hospitals implemented the reform at the same time. Nevertheless, this study supports the consistent literature on the topic and adds a more robust assessment of severity of illness.
Bottom line: The restriction on resident duty hours does not appear to affect patient mortality.
Citation: Prasad M, Iwashyna TJ, Christie JD, et al. Effect of work-hours regulations on intensive care unit mortality in United States teaching hospitals. Crit Care Med. 2009;37(9):2564-2569.