The Centers for Medicare & Medicaid Services explained how it arrived at the 2016 star ratings in a report describing its methodology for calculating overall hospital quality.
The ratings, which measure hospitals on a five-star scale, took into consideration 113 measures of inpatient and outpatient quality, according to the report. The data are derived from the the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey.
CMS grouped quality measures in seven categories, weighted by importance. The categories and their weighting are: mortality (22 percent), safety of care (22 percent), readmissions (22 percent), patient experience (22 percent), effectiveness of care (4 percent), timeliness of care (4 percent) and efficient use of medical imaging (4 percent).
CMS is also letting acute care hospitals peek at their upcoming hospital star ratings, at least through Feb. 14, before the ratings are added to the Hospital Compare consumer website in April.
The ratings have varied widely since debuting in April 2015. Initially, only 7 percent of the nearly 3,500 ranked hospitals received a five-star rating, as FierceHealthcare reported. The biggest chunk of hospitals, 40 percent, received three stars.
But an update in July showed that the number of hospitals receiving five-star ratings more than doubled. In October, the number of five-star hospitals tumbled to 207, below the 251 initially reported in April.