California’s Nurse-Patient Ratio Law Improves Safety

By Roy Maurer May 19, 2015

Researchers have concluded that California’s law governing minimum nurse-to-patient staffing ratios improves safety for nurses.

The results were published in the May 2015 issue of the International Archives of Occupational and Environmental Health.

California is the only state with such a law, which went into effect in 2004. “The ratios vary depending on the type of hospital service but are in the range of one nurse for every five patients,” said J. Paul Leigh, Ph.D., a professor in the department of public health sciences and the Center for Healthcare Policy and Research at the University of California Davis School of Medicine, and one of the authors of the research study.

Leigh and his colleagues used the Survey of Occupational Injuries and Illnesses prepared by the U.S. Bureau of Labor Statistics. The survey collects annual data on nonfatal injuries and illnesses from 150,000 to 200,000 companies. The researchers selected injury and illness data from 1999 to 2009 and combined it with data on hospital employment in California and the rest of the U.S. “We applied the ‘difference-in-differences’ method whereby the change in injury and illness rates before and after implementation of the law within California were compared to changes in injury rates for the same time period in the 49 other states and D.C. combined,” Leigh said.

They found that:

  • The California staffing mandate was associated with 55.57 fewer occupational injuries and illnesses per 10,000 registered nurses per year, which represents a 32 percent drop from the expected rate without the law, based on injury and illness rates before the law was enacted.
  • The estimated reduction in injury and illness rates for licensed practical nurses was 38 percent.

“While the data don’t tell us why the rates went down, the improved staffing ratios could lower rates of injuries and illnesses to nurses in a number of ways,” said Leigh. “For example, back and shoulder injuries could be prevented, if more nurses were available to help with repositioning patients in bed. Likewise, fewer needle-stick injuries may occur if nurses conducted blood draws and other procedures in a less time-pressured manner.”

Roy Maurer is an online editor/manager for SHRM.

Follow him @SHRMRoy


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