Hospital groups accuse CMS of ignoring concerns over Hospital Compare star ratings

Hospital organizations are blaming the Centers for Medicare and Medicaid Services for ignoring their concerns over the Hospital Compare star ratings program.

"We are deeply disappointed that we have not been given the opportunity to work with the Centers for Medicare and Medicaid Services to examine the serious concerns we have with its star ratings methodology, nor has CMS shared any data to demonstrate the validity of its methodology," they wrote to Patrick Conway, deputy administrator for Innovation and Quality for CMS.

The Thursday letter was signed by the American Hospital Association, the Association of American Medical Colleges, America's Essential Hospitals and the Federation of American Hospitals.

The hospital groups want CMS to share additional information with hospitals and the public about how accurately star ratings portray hospital performance; they urge CMS to address what they say are several significant underlying methodological problems with the star ratings.

[Also: Analyst says CMS star ratings program flawed, may create biased results]

"Until CMS has taken the time to address these problems and share information with hospitals and the public demonstrating that its star ratings methods offer a fair and accurate assessment of hospital quality, we strongly urge the agency to continue to withhold publication of the flawed star ratings."

This spring, the hospital groups and U.S. Senators asked CMS to delay the publication of the star ratings program.

In the letter to Conway, the hospital groups attached an analysis by an expert in econometrics stating that CMS' approach to overall hospital quality star ratings appears to have several shortcomings.

The main concern is the fairness and accuracy of social and economic factors and how this impacts hospital comparisons.

They want CMS to examine whether the flaws in the hospital-wide readmissions measure and the patient safety indicator (PSI-90) measure bias the rating against hospitals that care for more complex patients, the letter says.

Small hospitals may not have enough cases for accurate measurement, and in some cases, a number of the nation's best-known hospitals with the highest of ratings on other assessments, and that serve large numbers of low-income and complex patients, are slated to receive a small number of stars from CMS, they said.

"Since the sole purpose for creating the star ratings is to provide accurate information to the public to guide their decision-making about where to get their care, hospitals and patients alike must have meaningful information on whether the assessment is fair and accurate," the letter says.

[Also: 168 get 5 stars, 65 get 1 star in latest Hospital Compare patient experience ratings; See the list]

CMS's methodology is being reviewed by independent expert Frank Vella, chair of economics at Georgetown University.

"While the published methodology provides an adequate description of what CMS's assumptions were and what the agency did to calculate the star ratings, it provides very little insight into how well the methodology worked," they said.

The independent analysis shows the current model is based are flawed in a number of ways: It fails to account for other factors that cause substantial variation in performance, and instead attributes the variation solely to quality; it assumes the assignment of star ratings implies that hospitals have been measured on essentially an equal, or at least an equivalent, basis so that the comparisons are fair, and this isn't correct, the letter says.

The groups said they are also confused about the methodology. CMS has said that a quarter of hospitals were assigned a star rating based on 18 or fewer measures, while other hospitals were assigned a star rating based on two or three times that number of measures.

CMS refers to both 75 measures to assign star ratings and also 64 measures.

"Still, it is clear that there is a large difference in the number of measures comprising a star rating for smaller and less complex hospitals versus the number used to assess larger, multispecialty hospitals," the letter states.

The letter states other concerns and the groups urge CMS to share additional information with hospitals and the public about how accurately its star ratings portray hospital performance.

Until it does, the groups urge the agency to continue to withhold publication of the star ratings, the latest of which are due out in July.

Twitter: @SusanJMorse