Study throws cold water on link between star ratings and clinical outcomes

The Centers for Medicare & Medicaid Services’ star-ratings system has already been the target of considerable criticism, and a new study finds that the ratings’ emphasis on patient experience doesn’t produce reliable care quality data.

Researchers from Quantros, a safety and quality software provider, sent an advance copy of the study to FierceHealthcare. The study analyzed all CMS-rated hospitals on a combination of complication rates, mortality rates and Agency for Healthcare Research and Quality patient safety indicators to determine a composite score.

They found that nearly half of five-star hospitals had composite outcome scores below the national average with two-, three-, and four-star hospitals having the lowest percentage of poor performing hospitals.

The research also discovered no positive correlation between patient experience scores and composite outcomes; the closest thing to a trend was a statistically insignificant negative correlation.

“These findings clearly confirm that consumers cannot safely assume that hospitals with a CMS five-star rating will provide better clinical quality than other star-rated hospitals,” Quantros Chief Medical Officer Frank Mazza, M.D., said in a statement. “In fact, reliance on five-star ratings will place them at substantial risk of choosing a hospital that provides sub-standard care.”

The results sharply contradict those of an April study that found a strong association between CMS patient experience scores and care quality.

There are a few possible explanations for the difference, according to the Quantros report; first of all, the earlier study combined patient experience data from the second quarter of 2014 through the first quarter of 2015, resulting in what the company says is lopsided data. Moreover, it only assessed mortality and readmissions outcomes across acute myocardial infarctions, heart failure and pneumonia, rather than a broader set of clinical measures.

- here's the study announcement