Scope of CMS Quality Ratings

The United States Centers for Medicare & Medicaid Services (CMS) issues quality ratings on a five-star scale to hospitals, other care facilities, and health insurance plans. The quality ratings system (QRS) was established and assigned to CMS as part of the Patient Protection and Affordable Care Act initially for health exchanges,¹ but its scope has subsequently been extended to other aspects of the healthcare system. It is intended to provide transparency to both patients and healthcare providers and allow for easy comparison between care options.

Hospital ratings are derived from data that hospitals report to CMS, in addition to data that the Centers for Disease Control and Prevention and Veterans Health Administration collect.² The final five star rating is calculated by taking a weighted average across five categories: mortality, safety, readmission, patient experience, and timely and effective care. The first four categories are worth 22% each, while the fifth counts for 12% of a hospital’s rating. Each of the categories, in turn, are calculated from a number of different measures. Mortality, for example, is a sum of seven different measures, including death rate for heart attack patients, death rate for pneumonia patients, and deaths among patients with serious treatable complications after surgery.³ In the most recent hospital ratings, released in July 2024, 5.9% of U.S. hospitals received a 1-star rating, while 8.2% received 5 stars—but nearly 39% did not receive any rating,³ likely owing to insufficient data.

Similarly, nursing homes are rated based on quality measures that include rates of patient pain, mobility decline, and urinary tract infections. The ratings also take into account staffing metrics and observations from inspections, the latter of which center on how medications are managed, how staff and residents interact, and the extent to which residents are protected from physical and mental abuse.⁴

In addition to health exchanges, CMS quality ratings include health plans, allowing for the comparison of qualified health plans.¹ The ratings are calculated from a measure of clinical quality—which incorporates measures such as preventative care, chronic disease management, and behavioral health—and patient-reported experience. Plan efficiency and affordability are also taken into consideration.

Although individual physicians and care providers are not rated using the five-star system, CMS does provide star ratings for many clinics and physicians’ offices. Patients interested in comparing providers can do so using the Medicare.gov compare tool, which lists performance information for individual screening and treatment categories.

Not only are CMS quality ratings data useful for patients, they also can play an important role in informing public health interventions. One study, for instance, found that lower-rated nursing homes in West Virginia, as determined by the CMS quality scale, were more likely to experience COVID-19 outbreaks than higher rated ones.⁵ According to the research paper’s authors, “Health departments could use star ratings to help identify priority nursing homes in their jurisdictions to inform the allocation of IPC (infection prevention and control) resources.” Because these data are freely available, patients, researchers, and clinicians can all access and use them according to their needs.

References

1. QRS | CMS. https://www.cms.gov/medicare/quality-initiatives-patient-assessment-instruments/qualityinitiativesgeninfo/aca-mqi/quality-rating-system/about-the-qrs.
2. Hospitals – About the data | Provider Data Catalog. https://data.cms.gov/provider-data/topics/hospitals/about-data.
3. Hospitals – Overall hospital quality star rating | Provider Data Catalog. https://data.cms.gov/provider-data/topics/hospitals/overall-hospital-quality-star-rating.
4. Find Healthcare Providers: Compare Care Near You | Medicare. https://www.medicare.gov/care-compare/resources/nursing-home/health-inspections.
5. Bui, D. P. et al. Association Between CMS Quality Ratings and COVID-19 Outbreaks in Nursing Homes – West Virginia, March 17-June 11, 2020. MMWR Morb. Mortal. Wkly. Rep. 69, 1300–1304 (2020), DOI: 10.15585/mmwr.mm6937a5