Only a handful of healthcare markets have been given high star ratings by CMS across four different sectors, according to a study published in The BMJ, suggesting either high-quality care at one facility isn’t “dependent on or improves” quality in another or the ratings themselves are flawed.

The study was led by Jose Figueroa, MD, MPH, Harvard Medical School instructor and associate physician at Brigham and Women’s Hospital. He and his coauthors examined the star rating data from four CMS compare websites for hospitals, dialysis centers, nursing homes and home health agencies, calculating the mean star ratings across 304 Hospital Referral Ratings (HRRs) with a total of almost 34,000 facilities. HRRs were then ranked into terciles by mean star rating.

Of those 304 regions, only 6 (2 percent of HRRs) had all four of the healthcare sectors examined in the top tercile. 38 (12.5 percent) had three sectors in the top tercile, 71 (23.4 percent) had two sectors in top tercile and 111 (36.5 percent) had one sector in the top tercile. 78 regions (25.7 percent) had no sector ranked in the top tercile. Figueroa and his coauthors said this was similar to estimates of “what we might expect by chance alone.”

One possible explanation for these results is the star ratings themselves, which have been criticized by hospital groups and others as being a misleading measure of quality. Another could be the ratings don’t adequately adjust for socioeconomic status of the patient population. The authors did find significant demographic differences between HRRs with three or four top-ranked sectors and those with zero. Those with top-ranked sectors had higher median incomes ($59,989 vs. $50,395 in HRRs with zero top-ranked sectors), a smaller population living below the white population and more white residents, along with a lower level of Medicare spending per beneficiary ($8,556 per patient vs. $9,744 per patient in HRRs with zero top-ranked sectors).

“It suggests that measures should more adequately adjust for socioeconomic determinants of health,” Figueroa and his coauthors wrote.

Those criticisms may explain the poor concordance of high-quality facilities in a market detailed by the study. What little evidence they did find of what makes for a high-quality market across the four sectors—namely, being wealthier and having a larger white population—suggested some broader approach may be needed.

“Policies that promote accountability for quality across sectors (e.g. bundled payments and shared quality metrics) may be needed to systematically improve quality across sectors,” the study concluded.