Understanding the CMS Five-Star Methodology Change

Five-Star Overview

The Centers for Medicare & Medicaid Services (CMS) Five-Star Quality Rating System, implemented in January 2015, evaluates the quality of care provided by dialysis facilities in an effort to provide patients, their families and their caregivers the ability to easily compare dialysis facilities and determine where they would prefer to dialyze. Facilities are given a rating between one and five stars. Facilities with a five-star rating are considered to deliver care that is much above the industry average, while those with a one-star rating are considered to deliver care that is much below average quality.

Recently, Five-Star underwent two significant methodology changes: The data source used for adequacy metrics changed from claims to CROWNWeb, and the star ratings are now assigned based on thresholds. The remainder of this article focuses on the latter change, which will allow facilities to maintain or improve their star rating more easily.

Moving from a Forced Bell Curve to Thresholds

Previously, ratings were assigned using a forced bell curve. The distribution of ratings was constrained in the following manner:

• The top 10 percent of facilities were given five stars
• The next 20 percent were given four stars
• The middle 40 percent were given three stars
• The lower 20 percent were given two stars
• The bottom 10 percent were given one star

Under this previous methodology, Five-Star compared the performance of a facility to the performance of its peers in the same year. In the updated methodology, measure scores and ratings are determined by comparing a facility’s performance during a year to the industry’s average performance during the baseline year (which is currently 2014). This allows facilities to maintain or improve their star rating more easily; they no longer need to outperform a specific percentage of the industry to be rated favorably. If a facility either maintains or improves its performance on the seven quality measures from the baseline year, it can expect to maintain or improve its star rating. While the baseline year is currently 2014, a new baseline can be established in two scenarios—when the star rating is no longer effective at communicating differences in outcomes between facilities, or when quality measures are either added or removed.

This methodology change is effective for the star ratings that were released in October 2016 that evaluate performance in 2015, and represents a positive shift for three main reasons:

• Star ratings are no longer constrained to finite percentages
• Changes can be observed in performance over time
• The performance needed to achieve a four- or five-star rating is known

Dialysis facilities are still rated based on the same seven quality measures (divided into three domains):

• The Standardized Outcomes domain includes the Standardized Transfusion Ratio (STrR), the Standardized Mortality Ratio (SMR) and the Standardized Hospitalization Ratio (SHR).
• The Other Outcomes 1 domain includes a central venous catheter (CVC) measure and arteriovenous fistula (AVF) measure.
• The Other Outcomes 2 domain includes a combined Kt/V measure (adult hemodialysis, pediatric hemodialysis and adult peritoneal Kt/V) and a hypercalcemia measure (three-month calcium greater than 10.2 mg/d).

Facilities are given a star rating if they are eligible for at least one measure in each domain. The star rating is calculated by averaging the quality measures within each domain, and then averaging the domain scores. Peritoneal dialysis facilities are not eligible for the measures within the Other Outcomes 1 domain. CMS accounts for this by averaging only the scores in the Standardized Outcomes and Other Outcomes 2 domains.

Five-Star serves as a valuable tool that can help consumers identify the highest-quality center nearest them. The recent methodology changes to the program represent a positive shift for the dialysis industry, allowing changes in performance to be observed over time and removing inherent limitations on the number of facilities that can achieve a four- or five-star rating.