Risk Stratification for Return Emergency Department Visits Among High-Risk Patients

OBJECTIVES: To compare 2 methods of identifying patients at high-risk of repeat emergency department (ED) use: high Care Assessment Need (CAN) score (>= 90), derived from a model using Veterans Health Administration (VHA) data, and "Super User" status, defined as more than 3 ED visits within 6 months of the index ED visit. STUDY DESIGN: Retrospective cohort study. METHODS: Using McNemar's test, we compared rates of high-risk classification between CAN score and Super User status. We examined differences in patient characteristics and healthcare utilization across 4 levels of risk classification: high CAN and Super User status (n = 198), CAN < 90 and non-Super User (n = 622), high CAN and non-Super User (n = 616), or Super User and CAN score < 90 (n = 106). We used logistic regression to identify associations between risk classification and any ED visit within 90 days. RESULTS: Of 1542 veterans, 52.8% (n = 814) had a CAN score = 90 and 19.7% (n = 304) were Super Users (P <. 0001), indicating discrepant rates of high-risk classification. However, we found no differences in patient characteristics. Rates of subsequent ED use were high: 63.1% of patients had 1 or more ED visits. No levels of risk classification were associated with subsequent ED use within 90 days (P = .25). CONCLUSIONS: Among the VHA users with multimorbidity and 3 or more prior ED visits or hospitalizations, subsequent ED use was high. Although CAN scores have demonstrated utility for predicting hospitalizations and deaths, prior utilization and multimorbidity without further risk classification identified a high-risk group for repeat ED use.