Abstract 28: Variation in High-Value Cardiovascular Diagnostic Testing: Patient, Payer, and Hospital Effects

Abstract

Background: In patients hospitalized with 1) newly diagnosed heart failure (HF) or 2) acute myocardial infarction (AMI), assessment of left ventricular systolic function is a high-value test supported by guidelines. We examined the degree to which patient-, payer-, and hospital-level characteristics impact use of testing. Methods: We analyzed data from the Colorado All-Payer Claims Database, a repository of billing claims from all insurers who provide care in the state. We identified all patients with an index hospitalization for HF and AMI from 2010 to 2014. We excluded patients with a prior diagnosis of HF, and hospitals with fewer than 40 HF or AMI hospitalizations. We determined whether patients had a systolic function assessment performed within 60 days of hospitalization. We calculated adjusted rates of testing at the hospital level, and assessed for correlation of rates between HF and AMI patients. We used multilevel logistic regression to assess patient- and payer- characteristics associated with testing, and used median odds ratios to determine the residual variation in testing attributable to hospitals. Results: We identified 9,516 patients with HF and 10,315 patients with AMI (mean age 73 years, 48% women) among 36 hospitals. Overall, 74% of HF patients and 73% of AMI patients received testing. Testing rates among hospitals ranged from 56% to 82% for HF and from 42% to 83% for AMI (Figure). Correlation of testing rates for AMI and HF patients among hospitals was moderate (Spearman r=0.58; p<.001). Medicaid insurance was associated with lower likelihood of testing for both AMI and HF (ORs 0.77 [0.67-0.88] and 0.54 [0.47-0.62]; both p<.001). After multivariable adjustment, use of testing across sites varied by a median odds ratio of 1.39 [1.28-1.49] for AMI patients and of 1.25 [1.17-1.34] for HF patients, meaning that on average, patients had 1.39 and 1.25 higher odds of being tested if they received care at a higher performing hospital. Conclusions: Despite adjustment for patient- and payer-level characteristics, there is 1) significant residual variation in use of high-value cardiac testing and 2) correlation in testing rates for AMI and HF patients among hospitals. These results suggest that hospital-level characteristics and care processes may have a strong influence on use of high-value testing.