Quality Peer Group Indicators for CAHs (FMT Briefing Paper #38)



The purpose of this study was to identify peer groups of CAHs for analyzing quality performance. The study aimed to address the following research question: what is the best way to compare quality performance across CAHs that have different organizational characteristics, such as size, scope of services offered, structure, and location?

We identified six categories of hospital characteristics for analysis as potential quality peer group indicators. Using data from CMS and the American Hospital Association Annual Survey, we examined the distribution of CAHs across these hospital characteristics. We then examined correlations between potential indicators (to choose indicators that are not highly correlated), and examined relationships between CAH performance on Hospital Compare quality measures and the indicators (to identify indicators that were significantly and consistently associated with CAH quality performance). Finally, we shared these analyses with experts in rural hospital quality and sought their input to inform the final selection of quality peer group indicators. 

In the end, this study identified three factors that could be used to develop CAH quality peer groups: adjusted annual admissions, system affiliation, and census region) 


  • The majority of peer-reviewed studies on the relationships between hospital organizational characteristics and quality performance have not specifically examined Critical Access Hospitals.
  • Some national and state hospital quality measurement programs allow CAHs to report quality data, but most have a minimum number of cases for hospital-level comparisons.
  • Among CAHs, better performance on inpatient and outpatient process of care measures is significantly related to higher inpatient admissions, inpatient surgical volume, and outpatient/emergency room visits, location in the Northeast Census Region, system affiliation and accreditation. No consistent relationships were found between performance on process measures and either nurse staffing or payer mix.
  • Lower volumes of inpatient admissions and inpatient surgical volume among CAHs are significantly related to higher scores on ten of the 11 HCAHPS patient experience of care measures. HCAHPS scores also vary significantly by
    Census Region. Higher nurse staffing tends to be related to higher HCAHPS performance, but differences are small.
  • Lower-volume CAHs show higher variation in quality performance, compared to higher-volume CAHs.
  • Some studies and hospital quality measurement programs compare quality performance of hospitals by size, or compare CAHs to non-CAHs, but no studies were identified that used quality peer groups to compare quality across groups of CAHs.
  • Three factors—adjusted annual admissions (split into three categories), system affiliation (yes/no), and census region (Northeast, Midwest, South, West)—can be used to develop CAH quality peer groups, given their distributions across CAHs, relationships to range of quality performance, and contributions to the comparability across CAHs.


HCAHPS Hospital Compare Quality