Quantifying the utilization of medical devices necessary to detect postmarket safety differences: A case study of implantable cardioverter defibrillators

Abstract

Purpose: To estimate medical device utilization needed to detect safety differences among implantable cardioverter defibrillators (ICDs) generator models and compare these estimates to utilization in practice. Methods: We conducted repeated sample size estimates to calculate the medical device utilization needed, systematically varying device‐specific safety event rate ratios and significance levels while maintaining 80% power, testing 3 average adverse event rates (3.9, 6.1, and 12.6 events per 100 person‐years) estimated from the American College of Cardiology’s 2006 to 2010 National Cardiovascular Data Registry of ICDs. We then compared with actual medical device utilization. Results: At significance level 0.05 and 80% power, 34% or fewer ICD models accrued sufficient utilization in practice to detect safety differences for rate ratios <1.15 and an average event rate of 12.6 events per 100 person‐years. For average event rates of 3.9 and 12.6 events per 100 person‐years, 30% and 50% of ICD models, respectively, accrued sufficient utilization for a rate ratio of 1.25, whereas 52% and 67% for a rate ratio of 1.50. Because actual ICD utilization was not uniformly distributed across ICD models, the proportion of individuals receiving any ICD that accrued sufficient utilization in practice was 0% to 21%, 32% to 70%, and 67% to 84% for rate ratios of 1.05, 1.15, and 1.25, respectively, for the range of 3 average adverse event rates. Conclusions: Small safety differences among ICD generator models are unlikely to be detected through routine surveillance given current ICD utilization in practice, but large safety differences can be detected for most patients at anticipated average adverse event rates.

Medical device surveillance with electronic health records

“…The shortcomings of spontaneous reporting systems, which are well known in pharmacovigilance research 41,42 (including lack of timeliness, bias in reporting, and low reporting rates), also plague device surveillance efforts. 43 EHRs, with their continuous capture of data from diverse patient populations and over long periods of time, offer a valuable source of evidence for medical device surveillance in the real world, and complement these existing resources. Indeed, the FDA’s new five year strategy 44 for its Sentinel post-market surveillance system prioritizes increased capture of data from EHRs.…”

“…Submitting data to registries is voluntary and not all records capture complete details on primary procedure, surgical factors, complications, comorbidities, patient reported outcomes, and radiograph 40 , so existing state and health system-level registries are not comprehensive. The shortcomings of spontaneous reporting systems, which are well known in pharmacovigilance research 41,42 (including lack of timeliness, bias in reporting, and low reporting rates), also plague device surveillance efforts 43 . EHRs, with their continuous capture of data from diverse patient populations and over long periods of time, offer a valuable source of evidence for medical device surveillance in the real world, and complement these existing resources.…”