Abstract
BACKGROUND: Although Medicare Advantage (MA) plans provide coverage to >50% of Medicare beneficiaries, it is unclear whether MA claims can be used similarly to Medicare Fee-For-Service (FFS) claims for clinical outcomes assessment. In this study, we evaluate the accuracy of claims algorithms previously validated in FFS to assess comorbidities and outcomes in MA patients after aortic valve replacement. METHODS: We compared the concordance of 11 claims-based covariates (diabetes, hypertension, atrial flutter/fibrillation, myocardial infarction) and outcomes (stroke, disabling stroke, transient ischemic attack, major vascular complication, bleeding, permanent pacemaker implantation, death) among FFS and MA patients with the covariates and adjudicated outcomes in the multinational Evolut Low-Risk Trial (2016-2018). We used claims algorithms for 1-year outcomes and calculated sensitivity, specificity, positive predictive value, negative predictive value, and kappa, using adjudicated outcomes as the reference. We compared the kappa for MA versus FFS using the 2-sample z-test with a significance level of P<0.05. RESULTS: Among 1139 US patients aged 65+ years old in the Evolut Low-Risk Trial, 782 patients (175 MA and 607 FFS) were linked to claims data and had complete comorbidity data. Among all covariates, claims algorithms for covariates had sensitivities ≥85% for identifying diabetes, atrial flutter/fibrillation, and hypertension in MA and FFS. For the outcomes, sensitivities were ≥85% for bleeding (comprehensive), permanent pacemaker implantation, and death. The kappa was higher in MA versus FFS for diabetes (P=0.03) and hypertension (P=0.025) but was lower in myocardial infarction (P<0.0001). There was no statistically significant difference in the kappa agreement between MA versus FFS for any of the selected outcomes. CONCLUSIONS: Medicare claims have a similar level of kappa agreement in MA versus FFS for most covariates and outcomes. As patients shift to MA, ascertainment of outcomes using Medicare claims in postapproval studies remains valid for select outcomes.