Abstract Body (Do not enter title and authors here): Introduction/Background: Low-value care is defined as care where harms or costs outweigh patient benefits. Prior studies have suggested that approximately 1 of every 10 carotid ultrasound tests are low-value because they were performed among patients without neurologic symptoms or a history of stroke. However, these studies have used administrative claims data that may not account for all patient symptoms or include all guideline-recommended indications. We assessed the validity of a claims-based measure of low-value carotid ultrasound testing compared to a reference standard of chart review.
Hypothesis: Claims-based measures overestimate the proportion of carotid ultrasound tests classified as low-value care.
Methods: We conducted a retrospective cohort study of Medicare fee-for-service beneficiaries attributed to an accountable care organization with administrative claims data linked to electronic health record data. Using Current Procedural Technology codes, the first 150 patients that underwent carotid ultrasound in 2021 were identified. We applied a claims-based algorithm used by researchers and policymakers to identify if testing was low-value or appropriate. We used linked electronic health record data to assess appropriateness of testing using the 2012 American Heart Association clinical practice guidelines. We assessed agreement between claims and chart review using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Cohen’s Kappa.
Results: Among 150 patients (mean age 76, 55% male, 86% white) who underwent carotid ultrasound, 76 tests (51%) were considered low value by the claims measure and 63 (42%) by chart review. Claims based measures were 67% sensitive, 61% specific, with a PPV of 55% and NPV of 62%. Cohen’s Kappa coefficient was 0.27 (CI 0.11 - 0.42), indicating only fair agreement between claims and chart review.
Conclusion: We found that an often-used claims-based measure to identify low-value carotid ultrasound testing misclassifies a substantial proportion of tests as low-value. Using claims-based measures alone for assessing provider quality and making payment decisions could harm provider reputations and erode trust in the quality reporting system.