Long-term active surveillance of implantable medical devices: an analysis of factors determining whether current registries are adequate to expose safety and efficacy problems

The balance between preapproval and postapproval data collection required by regulatory agencies (eg, FDA) is gradually shifting.6 Traditionally, long-term active surveillance of device safety has relied on adverse event reports that physicians, healthcare institutions, manufacturers, and patients submit to the FDA and to regulators in other countries, and on regulator-required postapproval studies that manufacturers conduct. [...]previous research has demonstrated the shortcomings of postapproval studies7 and adverse event reports: these include under-reporting and lack of denominator data to conduct population-level adverse event estimates.7 8 Registries offer a promising alternative or adjunct: they have exposed serious device-related problems in the past and recent reports have highlighted their potential.9–11 Linkage of registries and creation of coordinated registry networks (CRN) are likely to become an important method for tracking patient outcomes and assessing the performance of devices. Considered as an effectiveness outcome.40 41 20%–25% of EVAR procedures are complicated by endoleaks.42 43 Excluding type II, the cumulative endoleak rate is 5.67% at 2 years.26 30-day all-cause mortality Most frequently used primary outcome in major clinical trials such as EVAR 1, EVAR 2 and ACE.44–47 Mortality varies from 0.5% to 3.6%48 based on different studies and different EVAR grafts.40 41 49 Secondary vascular intervention Major indications: endoleak, graft migration, kinking of limb grafts, stenosis and occlusions, and landing site enlargement.50 Reintervention rates are 17% for intermediate follow-up (up to 4 years) and 23% for a longer term follow-up (beyond 4 years) with a median of 6 years.51 Surgical mesh for POP QoL King’s College Pelvic Organ Prolapse Quality of Life (P-QoL)27–29 is the most commonly used validated questionnaire with nine domains. Total reoperation rate Reoperation due to postoperative complications and prolapse recurrence. Power for a generic binary outcome (table 2) was calculated for 1.5 times increased odds of underperforming compared with a gold standard performance rate per recommendations.19 For continuous outcomes, the power was computed for a one-sided alternative in a generalized estimating equations framework with a quasiscore-based test statistic20 assuming only one group, a linear effect of time and a range (0.05–0.50) of intraclass correlation coefficient, a parameter that accounts for correlations among repeated