CMS has reportedly miscalculated hospitals' star ratings since implementing the ratings system in 2016 by weighting specific categories more heavily than others, according to an analysis by Chicago-based Rush University Medical Center cited by Crain's Detroit Business.
Rush leaders discovered CMS' Overall Hospital Quality Star Ratings formula, which awards hospitals a 1- to 5-star rating based on their performance across seven categories, relied heavily on one measure: the PSI-90, or the Patient Safety and Adverse Events Composite, according to the report. Rush found CMS weighted the PSI-90 measure more heavily during the first four releases of the ratings, beginning in 2016, and focused more heavily on complication rates from hip and knee replacements for the latest release in December 2017.
The complication rates from hip and knee replacements accounted for 98 percent of a hospital's performance in the safety group, the report states. CMS told Rush officials the weight given to the PSI-90 measure lessened in the most recent ratings from December because the measures were calculated using new ICD-10 codes.
Rush officials expressed their concerns about the rating system to CMS in May, after the agency informed them the hospital's rating had fallen from 5 stars to 3 stars. CMS typically gives hospitals two months to preview their ratings before publishing them on its Hospital Compare website. A difference in rating is significant, as payers use them to negotiate contracts with the hospital and help consumers decide where to go to receive care, the report states.
"Quality and safety reporting is incredibly difficult. Our analysis shows there was a disproportionate weighting of the measures. We went back and forth with CMS to understand the issues, and given their announcement, we feel they responded appropriately," Rush University Medical Center CMO Omar Lateef, DO, told Becker's Hospital Review June 15. "This experience illustrated how hospitals could share their knowledge with the government to play a small part in optimizing the system. This type of collaboration between different hospitals and CMS, the government, is remarkable."
Leaders from the University of Chicago Medicine and the Association of American Medical Colleges, among other institutions, also reportedly contributed to the analysis.
CMS announced its plan to postpone the July release of hospitals' star ratings June 12. It is unclear when the new ratings will be released.
To access the full report, click here.