Area-Level Variation in Low-Value Head Imaging Services in the Emergency Department vs. Ambulatory Setting

Background Low-value imaging services contribute to wasteful spending and potential harm among patients enrolled in Medicare. Current strategies for reducing low-value imaging are blunt and have had limited success, with substantial variation across health systems and geographic regions. Examining geographic variation in low-value imaging through two distinct settings can help to develop insights towards refining solutions. In this study, we compared variation in the use of a common low-value head imaging service for Medicare Advantage (MA) enrollees in the emergency department (ED) versus the ambulatory setting, across healthcare referral regions (HRRs), to better understand patterns of care for these services and potential policies for reducing them. Methods This retrospective cohort study used the Humana Research Database to identify MA beneficiaries who were eligible for a low-value head imaging service for syncope in the ED or ambulatory setting. Analyses described HRR-level variation in adjusted rates of low-value imaging services per 100 patients in 2023 in both ED and ambulatory settings and compared rates by decile to better understand variation in the use of these services by setting. Results Among the final cohort of 114,542 patients, 28% received a low-value head imaging service. The mean HRR-level low-value imaging rate was over seven times higher in the ED compared to the ambulatory setting (40.1 versus 5.7 patients received a low-value imaging service per 100 eligible patients, respectively). However, geographic variation in low-value imaging was greater among patients receiving care in an ambulatory setting, in which HRRs in the top decile of low-value imaging had a rate 150% higher than HRRs in the bottom decile. In contrast, the ED had a 46% difference in the low-value imaging rate between HRRs in the top versus bottom deciles. Conclusions Findings show relatively higher rates of low-value head imaging for syncope in the ED compared to the ambulatory setting, with less geographic variation. This suggests a more intractable issue compared to the ambulatory setting, pervading across a broad swath of patients, providers, and regions. Greater geographic variation in the ambulatory setting may suggest an influence of unwarranted patient-level and systemic factors that could provide more opportunity for improvement. Trial registration: Not applicable.