Hospital rankings, including CMS' star system, confusing at best, misleading at worst: Analysts

Despite the good intentions of hospital ranking systems to rate hospitals on quality and help patients compare organizations side-by-side, the systems may do more harm than good, according to two reports. That includes one of the most prominent ratings systems, run by the Centers for Medicare & Medicaid Services.

The CMS star rating system in its current form is inconsistent and unintuitive, wrote a research analyst and an executive vice president from the Association of American Medical Colleges in a blog post for Health Affairs.

“Patients and families will find the newly released star ratings from CMS confusing at best and misleading at worst," wrote Susan Xu and Atul Grover, M.D., Ph.D.

The methodology that CMS uses to come up with star ratings is flawed, according to the post. It is supposed to rate all hospitals based on 64 quality measures from seven quality domains, with higher weight given to mortality, readmissions and patient safety.

But many of the hospitals didn’t have enough data to report on all the quality domains. In fact, they write, some hospitals only had data from one clinical outcome domain. But CMS calculated the findings by redistributing the weights of the missing quality domains to the areas where the hospital had sufficient data.

This disconnect results in some hospitals receiving five or four stars when they may not be a true representation of quality, Xu and Grover write.

Indeed, few of the nation’s most well-known hospitals earned the coveted five stars.

And a new whitepaper from FairChex, a healthcare provider value measurement tool offered by Global Excel Management, also questioned hospital ranking systems.

“Overall quality rankings for hospitals are useful in that they provide a general sense of which facilities are succeeding—on average—in providing higher-quality medical care. The problem is that assigning a single rating to an entire facility can mask significant variation between departments," the report said.

Furthermore, patients then may make a decision on inaccurate metrics for a specific procedure, which may then put them at risk for an adverse outcome, the report noted.