Rare adverse event monitoring of medical devices with the use of an automated surveillance tool.

Prospective outcomes surveillance using population level data allows for statistical methodologies and confounder adjustment not supported by the FDA's current monitoring system. We explored propensity score matching integrated into an automated surveillance tool as a method for confounder adjustment in an observational cohort. The application analyzed all patients undergoing PCI via femoral access route from 2002-2006. The rare outcome of interest was retroperitoneal hemorrhage (RPH) and the device was a vascular closure device (VCD). A propensity score model was developed to match VCD and non-VCD match patients. Our tool was able to detect sustained elevations in RPH among those patients who received a VCD. A root cause analysis revealed an association between high femoral access and RPH which prompted an educational program to modify clinical practice. Our results suggest use of propensity score matching can play a useful role in computer-based surveillance of rare events in a prospective cohort.