Navigating by Stars: Using CMS Star Ratings to Choose Hospitals for Complex Cancer Surgery

Abstract

Background: The Centers for Medicare and Medicaid Services (CMS) developed risk-adjusted "Star Ratings," which serve as a guide for patients to compare hospital quality (1 star = lowest, 5 stars = highest). Although star ratings are not based on surgical care, for many procedures, surgical outcomes are concordant with star ratings. In an effort to address variability in hospital mortality after complex cancer surgery, the use of CMS Star Ratings to identify the safest hospitals was evaluated.

Methods: Patients older than 65 years of age who underwent complex cancer surgery (lobectomy, colectomy, gastrectomy, esophagectomy, pancreaticoduodenectomy) were evaluated in CMS Medicare Provider Analysis and Review files (2013-2016). The impact of reassignment was modeled by applying adjusted mortality rates of patients treated at 5-star hospitals to those at 1-star hospitals (Peters-Belson method).

Results: There were 105 823 patients who underwent surgery at 3146 hospitals. The 90-day mortality decreased with increasing star rating (1 star = 10.4%, 95% confidence interval [CI] = 9.8% to 11.1%; and 5 stars = 6.4%, 95% CI = 6.0% to 6.8%). Reassignment of patients from 1-star to 5-star hospitals (7.8% of patients) was predicted to save 84 Medicare beneficiaries each year. This impact varied by procedure (colectomy = 47 lives per year; gastrectomy = 5 lives per year). Overall, 2189 patients would have to change hospitals each year to improve outcomes (26 patients moved to save 1 life).

Conclusions: Mortality after complex cancer surgery is associated with CMS Star Rating. However, the use of CMS Star Ratings by patients to identify the safest hospitals for cancer surgery would be relatively inefficient and of only modest impact.

Figure 1.

Inclusion criteria. Consort diagram of inclusion criteria, including patients older than 65 years with a diagnosis of cancer of the lung, colon, stomach, esophagus, or pancreas who underwent nonemergent cancer surgery, including lobectomy, colectomy, gastrectomy, esophagectomy, and pancreaticoduodenectomy, between January 1, 2013, and October 1, 2016, in a hospital with a Centers for Medicare and Medicaid Services (CMS) Star Rating.

Figure 2.

Overall observed  90-day mortality across The Centers for Medicare and Medicaid Services (CMS) Star Rating cohorts. The unadjusted 90-day mortality for each of the CMS Star Rating rated cohorts is represented on the y-axis. The whiskers atop each bar represent the 95% confidence interval, and the reported P value is for the Cochran-Armitage trend test.

Figure 3.

Modeled impact of reassignment on mortality. The observed mortality at 1-star hospitals  is represented as the blue bar for each of the procedures. The modeled “reassigned mortality” (orange bar) was intended to represent the mortality that would have been observed had the 1-star population been cared for at the 5-star hospitals. The reassigned mortality was determined by applying the risk coefficients for each independent variable achieved at the 5-star hospitals (using logistic regression) to the population of patients treated at 1-star hospitals (see Peters-Belson approach in "Methods"). The whiskers represent 95% confidence intervals.

Figure 4.

The number of patients moved (1 star to 5 stars) to save 1 life. The number of patients that would need to be moved from 1-star to 5-star hospitals to save a single life is represented by the blue bar. The total number of patients saved in each group per year as a result of this move is represented by the orange bar. The whiskers represent 95% confidence intervals.