OMOP established an open-source library of Health Outcomes of Interest (HOI) definitions for use in observational studies. Mini-Sentinel for the FDA also conducted identification of health outcomes projects. We have found that there is very little consensus in the literature about outcome definitions. Within the IMEDS Research Plan we are continuing projects to catalogue, systematize and investigate methods for defining health outcomes in administrative databases and EHRs. The links below provide links to definitions from the OMOP HOI initiative.