More nurses and patient outcomes

The clock is ticking on a potential Twin Cities nurses strike on July 6. The hospitals and nurses haven't been able to come to an agreement. A major sticking point in the negotiations is that the nurses union want hospitals to limit the number of patients nurses are required to care for during a shift. The hospitals are wary of agreeing to specific staffing ratios, especially since there are so many known-unknowns (to use Donald Rumsfeld's famous phrase) with the health care reform law.

Still, it makes intuitive sense that high nurse staffing ratios would be associated with better patient care and outcomes. A number of studies on the issue suggest that there's some insight to that common sense notion.

But an intriguing new study published by the National Bureau of Economic Research comes to a more skeptical conclusion. In The Effect of Hospital Nurse Staffing on Patient Health Outcomes: Evidence from California's Minimum Staffing Regulation, economists Andrew Cook (Resolution Economics LLC), Martin Gaynor (Carnegie Mellon), Melvin Stephens, Jr. (University of Michigan) and Lowell Taylor (Carnegie Mellon) look at the impact of California's 1999 Assembly Bill 394. It mandated maximum levels of patients per nurse in hospitals. The mandate went into effect in 2004 after several years of study and negotiation.

The scholars found that California's staffing requirement succeeded in decreasing the patient/nurse ratio in hospitals that didn't meet the standard before the law was enacted. However, they found no evidence that the higher staffing ratios improved patient safety at these hospitals. "Our empirical results suggest that a mandate reducing patient/nurse rations, on its own, need not lead to improved patient safety," they write. "This is not to say, though that nurse staffing decisions are unimportant as a component in a hospitals's overall strategy for ensuring high patient safety."

In other words, management and basic strategy matters.

To be sure, studies like this are never definitive. The data is always incomplete and flawed by definition. It's extremely difficult to establish cause and effect no matter how hard the scholars try. This isn't a criticism of the scholars. It's in the nature of the beast and the scholars are very forthright about the limitations of their study. Still, California's experience provides a real world case study and it's disappointing the results weren't better--that is, from a patients perspective.

It's worth noting that another NBER study found a dismaying but suggestive short-term patient consequences from a strike. I posted on that earlier.

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