Objective: To examine correlations of commercial health plan performance on Health Plan Employer Data and Information Set (HEDIS) effectiveness-of-care measures with utilization rates, as a proxy for cost.
Study design: Cross-sectional study of 254 commercial health plans.
Methods: This report used data reported by commercial managed care plans in the 2003 HEDIS dataset. Utilization measures included access to care (the proportion of adults with at least 1 primary care or preventive visit), outpatient use (the number of outpatient visits per 1000 members per year), inpatient discharges (the number of inpatient discharges for medical conditions per 1000 members per year), and inpatient days (inpatient hospital days for medical conditions per 1000 members per year). A composite quality score was calculated from HEDIS indicators. Estimates of health plan membership demographics were identified from Consumer Assessment of Health Plans (CAHPS) survey data. Of 316 reporting plans, 254 reported sufficient data to be included in this analysis. Bivariate correlations and multivariate regressions (controlling for health plan and membership characteristics) were conducted.
Results: Quality was positively correlated with access to outpatient care (r = 0.46, P < .001), negatively associated with inpatient days (r = -0.30, P < .001), and not associated with total outpatient visits (r = 0.04, not significant). Regression results controlling for selected plan and member characteristics demonstrated similar findings.
Conclusions: Although the mechanism of this cross-sectional association is unclear, these data provide important starting points for further research on the interrelationships of quality and resource use.