The CMS dialysis five-star rating explained

Five stars summarise several outcome measures, each compared with what CMS expects.

What goes into it

CMS uses standardised ratios for patient survival (deaths compared with expected), hospitalisation, hospital readmission, transfusion, emergency-department visits, and the percentage of patients waitlisted for a kidney transplant. Each facility is compared with national expectations adjusted for its patients' age, race, and whether they have diabetes, among other factors.

Reading a single measure

A measure is reported as "better than expected", "as expected" or "worse than expected". A facility can be better than expected on survival while worse than expected on hospitalisation — the star rating weighs the measures together, but the individual results on each facility page are worth reading separately.

Why some facilities are unrated

Facilities with too few patients in the reporting period, or too little data on individual measures, do not receive a star rating. "Not rated" is not a quality signal.