There’s a better way to score hospitals with 1 to 5 stars, researchers say

The creators of CMS’s Overall Hospital Quality Star Rating ratings system—aka “Hospital Compare”—intended to present healthcare consumers with an easy, user-friendly way to choose a hospital. However, since the ratings went live in 2016, the system has proven both confusing to consumers and confounding to hospitals.

So say researchers at Henry Ford Health System in Michigan who have published a study in the American Journal of Medical Quality that includes a tested suggestion for a simple fix.   

Focusing on the eight measures in the heavily weighted Safety of Care category, lead author David Nerenz, PhD, and colleagues examined the soundness of CMS’s assumption that one underlying characteristic neatly ties together all eight measures. For this they worked with data from a cohort of 674 hospitals.

They also developed and tested an alternative weighting method based on Hospital Compare’s ratings for a single academic medical center.

CMS’s scoring system assigns one to five stars in seven categories comprising nearly 60 individual measures, weighting four categories (including Safety) at 22 percent each toward a hospital’s total score.

Nerenz et al. tested this formula by assigning equal weight to each of Safety’s eight measures and taking into account a hospital’s caseload and how this impacts the accuracy of each measure.

They found their method significantly changed the safety scoring for the single teaching hospital, which went from a below-average -2.35 by CMS’s calculations to an above-average +1.65 by the alternative approach.

“A stated aim of the Hospital Star Ratings program is to effectively summarize available hospital performance measures on Hospital Compare into a single, summary rating,” said study co-author Brian Waterman, PhD, MPH, of the Missouri Hospital Association, in a news release. “Our study results indicate that the current form of the methodology employed by CMS likely leaves important information about safety of care effectively out of the mix.”