Limitations
There are several limitations inherent to this observational study using administrative data. First, Medicare administrative claims data are a secondary database used primarily for billing purposes, not for clinical research purposes; therefore, traditional clinical adjudication is not conducted. It is possible that reinterventions, complications, or comorbidities could be missed, improperly coded, or inadequately documented in administrative claims. However, our prior analyses suggest that this probability is low,6 and, if anything, claims-based studies tend to overestimate adverse events.14 We would also not expect this to have a differential impact between the two study arms. Second, as with any observational study, the possibility of residual confounding following statistical adjustment for measured confounders cannot be completely eliminated. Third, because our study does not include device interrogation data, we are unable to assess variables such as programmed lower rates, pacing thresholds, and battery longevity which may be of particular interest when assessing the need for device reintervention. Finally, due to data availability, this analysis is limited to the Medicare FFS population and does not capture outcomes beyond December 31, 2020.