CMS last week updated hospital quality star ratings on Medicare's Hospital Compare website and proposed revamping its current model for rating hospitals.

How CMS calculates hospital star ratings

The overall hospital star ratings are based on 57 quality measures across seven categories:

• Effectiveness of care;
• Efficient use of medical imaging;
• Mortality;
• Patient experience;
• Readmissions;
• Safety of care; and
• Timeliness of care.

CMS for this year's ratings curbed the ratings' reliance on patient experience and put more weight on prompt care and readmission rates. CMS this year also did not apply the winsorization method to limit "extreme hospital outliers" in the data and "minimize their effect on the overall ratings." Instead, CMS used k-means clustering under which the agency repeatedly categorized hospitals into the five star-rating groups until the hospitals in each group were sufficiently similar to each other and distinct from hospitals categorized in other groups.

CMS said it continued to weigh each hospital's average score for each of the seven quality categories in the same way as in previous methodologies. Mortality, safety of care, readmissions, and patient experience each accounted for 22% of a hospital's overall score, while measures of effectiveness of care, timeliness of care, and efficient use of medical imaging each accounted for 4% of the overall rating.

How hospitals performed

Of the more than 3,724 eligible for a star rating:

• 293 hospitals received a five-star rating, compared with 112 hospitals that received a five-star rating in December 2017;
• 1,087 received a four-star rating, compared with 970 hospitals that received a five-star rating in December 2017;
• 1,263 received a three-star rating, compared with 1,770 hospitals that received a five-star rating in December 2017;
• 799 received a two-star rating, compared with 723 hospitals that received a five-star rating in December 2017; and
• 282 received a one-star rating, compared with 121 hospitals that received a five-star rating in December 2017.

CMS did not assign star ratings to 1,060 hospitals for which it lacked sufficient data, Modern Healthcare reports.

CMS proposes changes to hospital ratings

Separately, CMS in a 48-page request for comment asked for feedback on the agency's plan to revamp how hospitals are rated. The agency wrote that it is considering replacing its current model with a more explicit approach, such as using an average of the quality measurements on which the ratings are based. Specifically, CMS said it is considering whether to:

• Assign weights to each of the model's measures rather than using a separate model to select the weights;
• Assign hospitals to peer groups based on their sizes or statuses and compare hospitals within those peer groups;
• Launch a customized star-rating tool for users to view ratings based on what they value;
• Release the star ratings annually using a user-friendly tool; and
• Remove measures with a statistically significant negative loading from the ratings.

CMS in the request said the proposal is a "long-term" consideration, and any potential changes would not take effect until the 2020 quality reporting year or later. CMS is accepting public comments on the proposal through March 29.

Reaction

Tom Nickels, executive vice president of the American Hospital Association (AHA), said CMS' "update has not addressed the major concerns about the methodology and usefulness of the star ratings." Nickels said AHA "appreciate[s] that CMS continues to seek comment on changes, but would have preferred the agency had waited to release these ratings until a more reliable methodology is in place."

Bruce Siegel, America's Essential Hospitals (AEH) president and CEO, said he "find[s] it unfortunate that CMS decided to publish hospital star ratings today … as the agency proposed changes that recognize ongoing flaws in the ratings methodology." He said, "Those flaws contribute to ratings that mislead consumers and disadvantage hospitals that care for vulnerable patients, rather than reflect true hospital performance and improvement. The ratings also fail to account for social risk factors beyond a hospital's control and that affect performance" (Morse, Healthcare Finance News, 2/28; Stein, Inside Health Policy, 2/28 [subscription required]; Castellucci, Modern Healthcare, 2/28; Knowles, Becker's Clinical Leadership & Infection Control, 2/28; AHA statement, 2/28).