Abstract 20: Use of Administrative Claims to Ascertain Outcomes in Randomized Clinical Trials for Transcatheter Aortic Valve Replacement: Findings From the Extending Trial-based Evaluations of Medical Therapies Using Novel Sources of Data (EXTEND) Study

Introduction: Administrative claims may be a low cost alternative to traditional clinical trial event adjudication, but whether claims data can validly substitute for adjudicated outcomes to reproduce trial-derived treatment effects is uncertain.

Methods: We linked adults aged ≥65 in the US CoreValve Pivotal High Risk (HiR) and Surgical or Transcatheter Aortic Valve Replacement in Intermediate-Risk Patients (SURTAVI) Trials to 100% Medicare inpatient claims (2003-2016). Primary (i.e. death and stroke) and secondary trial endpoints (i.e. bleeding, acute kidney injury, cardiogenic shock, pacemaker implantation, aortic valve reintervention, myocardial infarction, and major adverse cerebrovascular and cardiovascular events [MACCE]) were compared across treatment arms (i.e. TAVR vs. SAVR) using outcomes derived from claims at 1 year (HiR) or 2 years (SURTAVI), and compared with trial-adjudicated outcomes.

Results: Among 600 linked HiR participants (linkage rate 80.0%), the rate of the trial’s primary endpoint of all-cause mortality at 1-year was 13.7% for TAVR and 16.4% for SAVR using both trial data (HR 0.84, 95% CI 0.65-1.09; p = 0.33) and claims data (HR 0.86, 95% CI 0.66-1.11; p = 0.34; interaction p-value = 0.80) (Figure). Among 1004 linked SURTAVI trial participants (linkage rate 60.5%), the trial’s primary endpoint of combined death and stroke at 2-years was 12.9% for TAVR and 13.1% for SAVR using trial data (HR 1.08, 95% CI 0.79-1.48, p = 0.90), and 11.3% for TAVR and 12.5% for SAVR patients using claims data (HR 1.02, 95% CI 0.73-1.41, p = 0.58; interaction p-value = 0.89) (Figure). Procedural secondary outcomes (e.g., aortic valve reintervention, pacemaker implantation) were more concordant between trials and claims than non-procedural outcomes (e.g. bleeding, cardiogenic shock, stroke). Acute kidney injury, myocardial infarction, and MACCE outcomes were also concordant between data types.

Conclusions: In both HiR and SURTAVI trials, ascertainment of trial primary endpoints using claims reproduced both the magnitude and direction of treatment effect observed in adjudicated event data. Non-fatal secondary outcomes displayed variable concordance. Use of claims to substitute for adjudicated outcomes in traditional trial treatment comparisons may be a valid alternative for some endpoints.