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Fewer registered nurses in hospitals linked to more cases of postoperative pneumonia

A new study of a national sample of over 500 hospitals suggests that concern about nurse staffing may be warranted. The study demonstrated a connection between fewer RN hours per patient day and more cases of postoperative pneumonia among patients undergoing major surgery.

Chunliu Zhan, M.D., Ph.D., Peter J. Gergen, M.D., M.P.H., and Jayasree Basu, Ph.D., of the Agency for Healthcare Research and Quality, and their colleagues linked discharge data from hospitals in 13 States from 1990 to 1996 with American Hospital Association data on hospital characteristics and nurse staffing. They used these data to examine the impact of nurse staffing on four postsurgical complications: venous thrombosis/pulmonary embolism, pulmonary compromise, urinary tract infection (UTI), and pneumonia, among patients undergoing major surgery.

After controlling for other factors—such as patient case mix and hospital characteristics—fewer RN hours per patient day were found to be significantly associated with more postsurgical pneumonia. Contrary to anecdotal reports of declining RN staffing levels, this study found slightly increased RN hours per patient day, as well as steady increases in physician and resident/intern hours per patient day during the study period.

This study, which used different data and different methods, reached the same conclusions as another recent AHRQ-funded study by Jack Needleman, Ph.D., of the Harvard School of Public Health, and Peter Buerhaus, Ph.D., R.N., of the Vanderbilt University School of Nursing. Their findings were published in the May 30, 2002 issue of the New England Journal of Medicine 346(22), pp. 1715-1722.

For more information on the current study, see "Nurse staffing and postsurgical adverse events: An analysis of administrative data from a sample of U.S. hospitals, 1990-1996," by Christine Kovner, Ph.D., R.N., Cheryl Jones, R.N., Ph.D., Dr. Zhan, and others, in the June 2002 Health Services Research 37(3), pp. 611-629.

Reprints (AHRQ Publication No. 02-R079) are available from the AHRQ Publications Clearinghouse.

Editor's Note: See the June 2002 Research Activities Feature Story, for a summary of the article by Drs. Needleman and Buerhaus.

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