In a somewhat unexpected move, the Centers for Medicare & Medicaid Services today unveiled star ratings for hospitals based on patient HCAHPS scores.

These patient experience ratings — in which a hospital earns anywhere from zero to five stars — are a prelude to an overall rating system expected in 2016 that will be based on the full range of quality measures now published on the CMS Hospital Compare website. The agency already does similar ratings for nursing homes, according to a CMS fact sheet. The hospital ratings will be updated quarterly.

An official for the American Hospital Association said hospital leaders are supportive of giving patients the information they need to make decisions, but there are some potential pitfalls when creating a single, overall rating.

"While star ratings could be an effective way to make quality information easier to understand, the devil is in the details," said Akin Demehin, AHA senior associate director of policy, in an emailed statement. "There’s a risk of oversimplifying the complexity of quality care or misinterpreting what is important to a particular patient, especially since patients seek care for many different reasons."

Demehin added that "hospital rating systems also need to keep up with the rapidly evolving nature of the quality measures underlying them."

The first set of overall patient experience ratings, which are calculated using 11 individual star ratings, are based on discharge data from July 2013 through June 2014. The results are adjusted for such things as patient mix and the mode of giving the survey.

Seven of the individual ratings are composite HCAHPS measures, which are those based on two or more categories, each making up one-ninth of the overall average score:

• Communication with nurses

• Communication with doctors

• Responsiveness of hospital staff

• Pain management

• Communication about medicines

• Discharge information

• Care transition

Four other individual questions in effect each make up one-eighteenth of the overall score:

• Cleanliness of hospital environment

• Quietness of hospital environment

• Overall hospital rating

• Recommendation of the hospital

CMS already uses stars to rate physician practices on a limited number of measures, dialysis facilities and Medicare Part C and Part D plans.