Published 3/1/2018
Jasmine Saleh, MD, MPH; Andrew Krause, MD; Zain Sayeed, MD, MHA; Muhammad T. Padela, MD, MSc; Khaled J. Saleh, MD, MSc, FRCS(C), MHCM, CPE

The CMS Overall Hospital Quality Star Rating System

Understanding the impact on patients and providers
The Centers for Medicare & Medicaid Services (CMS) Overall Hospital Quality Star Ratings (Star System) are an effort to improve quality and efficiency of care for patients.

The CMS Star System is based on 57 existing quality measures reported on the CMS Hospital Compare website. By summarizing complex quality data into a single star rating, CMS hopes to provide consumers with an understandable way to compare hospital performance.

Previous articles in this series have provided the background and history of the CMS Star System and examined its impact on hospitals. This article discusses its impact on patients and physicians. It also makes recommendations for improving the validity and reliability of the CMS Star System.

Impact on patients
As hospitals differ in the safety and quality of care they deliver, choosing a provider can be overwhelming for patients and their families. The CMS Star System aims to make this process easier by cumulating quality measures into a simple five-star model.

The CMS Star System seeks to offer patients ready access to comparative information, thereby enabling them to become more engaged in their own health care and make more informed consumer decisions.

Whether the system actually impacts consumer choices, however, is debatable. Some studies report that patients value information from online reviews, with approximately 59 percent of patients using them "often" or "sometimes" and 37 percent of patients avoiding providers with low ratings.

According to one study conducted by a medical technology reviews company, 77 percent of patients reported using online reviews as a first step in seeking a provider; 16 percent used the reviews to validate their choice of physicians. However, an article in the Journal of the American Medical Association argued that patients rarely utilize publicly reported quality data when seeking care, turning instead to recommendations from family and friends. The author also noted that the information in public reports, such as readmission rates and influenza guidelines, may not be relevant to patients.

Although the simplicity of the CMS Star System may enable comparisons among hospitals, its methodology contains several potential flaws that can mislead consumers. For example, the Star System does not consider socioeconomic factors or the complexity of cases treated.

As a result, the star ratings may skew in favor of smaller, private, nonteaching hospitals treating less complex cases and "cherry-picking" healthier patient populations. This flawed methodology risks consumers choosing a hospital for its rating, rather than its focus on their particular medical condition. As a result, patients may receive poorer quality of care and face potentially serious consequences.

Impact on physicians
Publicly reported data provide feedback regarding healthcare professionals' and hospitals' performance.

Some analysts believe that physicians would be motivated to provide a higher quality of care to obtain better data performance, protect their reputations, and lead more patients to choose their services. Theoretically, data-driven feedback from the CMS Star System highlights a physician's deficiencies, allowing them to improve future performance.

However, the CMS Star System may also lead healthcare professionals and hospitals to deny beneficial treatment to high-risk patients to improve their star ranking.

Without a workable risk-adjustment technique, the CMS Star System may encourage patients to avoid providers and hospitals with lower scores that may not accurately represent the quality of their care.
Similarly, physicians and hospitals providing care for patients from lower socioeconomic backgrounds receive poorer ratings.

If physicians and hospitals feel punished for treating particular patient subgroups, such as those with significant comorbidities or those who require complex surgical procedures, they may avoid those whom they fear might lower their performance scores. In addition to "cherry-picking" healthier patient populations, healthcare providers and hospitals may manipulate their data by exaggerating pre-existing comorbidities, referring patients elsewhere, or not reporting certain outcomes.

Adequate risk adjustment is necessary for quality data included in the CMS Star System.

The current calculation does not factor in the complexity of conditions treated by providers at certain hospitals or the differences in patient populations at each hospital. Without proper risk adjustments, the published data are misleading for both patients and healthcare providers. Adequate risk adjustment would help address avoidance of higher risk patients and procedures with higher complication rates by physicians and hospitals.

The CMS Star System could be further stratified to rate each hospital by medical specialty. Other hospital rating systems, such as that published by U.S. News & World Report, rank hospitals by as many as 16 specialties. This approach would enable patients to choose the hospital best suited for their particular health concern.

For instance, if a hospital has an overall 2 star rating, but is the highest rated hospital for orthopaedics in the area, patients may still choose to have a joint replacement there. In these situations, patients may not be as concerned about the other measures that result in a lower star rating, as long as they receive high quality of care for their condition. Stratifying the star rating of each hospital by specialty may improve how patients compare hospitals based on their individual care needs.

The CMS Star System provides a simple, singular assessment for patients to compare hospitals' performances.

Although this transparency may empower them to become more engaged in their health care, the flawed methodology of the CMS Star System may lead patients to avoid the optimal facility for their particular condition.

Additionally, this methodology may inadvertently lead to fewer options for patients with complex cases. CMS should modify its methodology to include risk adjustment and stratification by specialty. This outcome would make the information more reliable for patients, enabling them to make informed decisions regarding their care. It would also encourage physicians to continue improving the quality of care they provide.

Jasmine Saleh, MD, MPH, is the director and cofounder of Global Health Conscious NFP; Andrew Krause, MD, is a member of the department of internal medicine at the Detroit Medical Center; Zain Sayeed, MD, MHA, and Muhammad T. Padela, MD, MSc, are members of the department of orthopaedics at the Detroit Medical Center; and Khaled J. Saleh, MD, MSc, FRCS(C), MHCM, CPE, is the executive-in-chief of orthopaedics at the Detroit Medical Center.

Editor's note: This article is the last of a three-part series detailing the CMS Overall Hospital Quality Star Rating. Previous articles appeared in the January and February issues of AAOS Now.


  1. Goodrich K, Conway P: CMS Hospital Star Ratings First Step in Effort to Improve Quality Measures. AAMCNews. 2016; https://news.aamc.org/patient-care/article/cms-star-ratings-effort-improve-quality-measures/
  2. Goodrich K: Helping Consumers Make Care Choices through Hospital Compare. The CMS Blog. 2016; https://blog.cms.gov/2016/07/27/helping-consumers-make-care-choices-through-hospital-compare/
  3. Whitman E: Will patients heed hospitals' star ratings? Modern Healthcare. 2016; www.modernhealthcare.com/article/20160801/NEWS/160809996
  4. Mahoney D: Online Physician Reviews: Adopting Transparency Standards Protects Your Brand. Press Ganey. 2016; www.pressganey.com/resources/blog/online-physician-reviews-adopting-transparency-standards-protects-your-brand
  5. Lee V: Transparency and Trust—Online Patient Reviews of Physicians. N Engl J Med. 2017;376:197–199.
  6. Cohen JK: How do patients select a new physician? 77% say online reviews. Health Information Technology. 2016; www.beckershospitalreview.com/healthcare-information-technology/how-do-patients-select-a-new-physician-77-say-online-reviews.html
  7. Bilimoria KY, Barnard C: The New CMS Hospital Quality Star Ratings: The Stars Are Not Aligned. JAMA. 2016 Nov 1;316(17):1761–1762.
  8. White J: CMS' new star ratings: How hospitals rank so far. 2016 www.healthcarebusinesstech.com/star-ratings-quality-cms/
  9. Long G: Quantros Study Finds No Correlation Between CMS Star Ratings and Quality. MiraMed. 2016; www.miramedgs.com/ealerts/586-quantros-study-finds-no-correlation-between-cms-star-ratings-and-quality
  10. Ellimoottil C, Leichtle SW, Wright CJ, et al: Online physician reviews: The good, the bad, and the ugly. Bull Am Coll Surg. 1 Sept 2013:98(9):34–39.
  11. Emmert M, Sander U, Pisch F: Eight Questions About Physician-Rating Websites: A Systematic Review. J Med Internet Res. 2013 Feb; 15(2):e24.
  12. Berwick DM, James B, Coye MJ: Connections between quality measurement and improvement. Med Care. 2003; 41:I30–I38
  13. Centers for Medicare & Medicaid Services: CMS Quality Measure Development Plan: Supporting the Transition to the Merit-based Incentive Payment System (MIPS) and Alternative Payment Models (APMs). Baltimore, MD: Centers for Medicare & Medicaid Services; 2016.
  14. Minami CA, Dahlke A, Bilimoria KY: Public Reporting: An Emerging opportunity to improve care and inform patients. Annals of Surgery. Feb 2015;261(2): 241–242.
  15. Hospital Quality Star Rating on Hospital Compare Public Input Period: Enhancements of the Overall Hospital Quality Star Rating. 2017; www.cms.gov/Medicare/Quality-Initiatives-Patient-Assessment-Instruments/MMS/Downloads/Hospital-Compare-PC-2017.pdf