Study: Nurse Ratio Law Has Mixed Results on Quality of Care

Authors of a new study contend that California’s 2004 law mandating minimum nurse-to-patient ratios in hospitals has had mixed results on quality of care for patients.

California Nurses Association officials said the study’s findings do not support the authors’ conclusions. The nurses association was the driving force behind the ratio law and now is lobbying to get other states to adopt similar legislation.

The study, “California’s Minimum Nurse Staffing Legislation: Results From a Natural Experiment,” was published last month in Health Services Research, the bimonthly journal of AcademyHealth. Barbara Mark from the University of North Carolina-Chapel Hill School of Nursing was the lead author in a group of five researchers and authors.

Joanne Spetz, a study author and researcher at the Center for the Health Professions at UC-San Francisco, said more research is needed to determine how nurse staffing laws influence quality of care.

“The bottom line is there are some things we can point to and say the nursing ratio law has definitely had an impact, but so far, quality of care is not one of them,” Spetz said. “More research is needed.”

Spetz said, “There is evidence that ratios are linked to higher nurse satisfaction and a sense of a better work environment. They have had significant impact on financial margins of hospitals in California and in some cases reduced levels of charity care by hospitals who had to spend more to hire nurses.”

“In some areas, some hospitals showed improvement, but we don’t have a great handle on the overall impact of nursing ratios on quality of care,” Spetz said.

‘Failure To Rescue,’ Infection Detection

The study compared quality of care and staffing in California hospitals before and after the staffing law took effect with hospitals in 12 other states without staffing legislation. Researchers divided California hospitals into four groups based on staffing levels prior to the legislation. To measure the quality of patient care, they analyzed data on patient deaths and patient safety indicators collected from 2000 to 2006. The patient safety indicators provided information on patient complications after surgeries and procedures.

Two of the most significant findings in the study showed that California hospitals with the lowest and highest pre-legislation staffing levels (groups 1 and 4) had a significant decrease in the number of deaths resulting from complications, also known as “failure to rescue.”

Group 3 hospitals showed an increase in the number of infections identified after the legislation, which researchers said could be a result of more nurses being better able to detect infections.

Although both findings could be indications that larger nursing staffs led to fewer deaths from hospital complications and greater awareness of infections, researchers said the cause-effect relationship was not clear, nor did they necessarily determine a change in quality of care.

“That’s where more research is needed,” Spetz said. “If research shows that after more infections are identified patient outcomes are improved because of increased nurse staffing, that could be a real marker of improved quality of care.”

The study showed no significant changes in respiratory failure and infections following surgery.

Nurses’ Union Disagrees

In a written response to requests for comment about the study, California Nurses Association spokesperson Liz Jacobs said that “the results of the study were not sufficient to support the authors’ conclusions. In fact, the evidence derived from these tests points to the improvement in rescuing patients with nursing ratios in place.”

The nurses association also criticized research methodology in the study.

“The authors do not use direct data for staffing ratio levels in either California or in the comparison states,” Jacobs said. “For California, the authors used OSHPD (state Office of Statewide Health Planning and Development) hours, which are based on cost centers. Hospitals reporting to OSHPD are asked what type of service is performed, not where the patient is physically placed in the hospital. It is possible that different hospitals would place a patient in different units in their respective hospitals,” Jacobs said.

“The data is based on number of hours worked, not the actual number of RNs working,” Jacobs said.

“In the non-California states, the authors use American Hospital Association data, which has no information on how many nurses are on what units. They use a statistical technique to derive estimates for the number of nurses on the units. They then compare it to the California data to verify. But as pointed out above, the California data is highly problematic to start with,” Jacobs said.

Hospital Association Agrees With Researchers

B.J. Bartleson, vice president of Nursing and Clinical Services at the California Hospital Association, said the results of the latest study are consistent with previous attempts to measure the nursing law’s effects on quality of care.

“There’s no direct relationship between how many nurses are on duty and quality of care,” Bartleson said. “In at least eight studies since the law took effect, we’ve seen pretty much the same results — care might be improved in some hospitals in some situations, but not in others. And in a lot of situations, care is the same.”

California is the only state with a law mandating nurse-to-patient ratios for hospitals. A dozen other states have laws or legislation in the works that require either public disclosure of nurse staffing levels or hiring committees that include nurses.

Several other states are reportedly considering nurse staffing legislation. A ratio law similar to California’s is expected to surface in the Minnesota Legislature next year.

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