EpiCore—A Common Data Model for Pharmacoepidemiological Studies in Denmark, Norway, and Sweden

Purpose: The use of common data models (CDMs) is increasing; however, the complexity of many CDM frameworks constitutes a barrier for their use. For many local and collaborative use cases, simpler CDMs can suffice. Here, we propose the EpiCore CDM, a simple CDM framework for use in Scandinavian pharmacoepidemiological studies. Methods: The EpiCore CDM was developed based on a set of guiding principles. It should (i) accommodate the most common elements of typical data sources in the field and region, (ii) be accessible to users without needing advanced technical expertise or database infrastructure, (iii) prioritize structural and syntactic harmonization of data and defer clinical concept mapping to the analytical phase, (iv) be usable in both collaborative and single site settings, and (v) include support for quality control procedures. Results: The EpiCore CDM comprises two mandatory administrative tables (person and observation), six optional event tables (diagnosis, procedure, encounter, drug, primcare, and cancer) and three optional lookup tables (drug_info, organisation_info, and prescriber_info). Each table, along with its columns and constraints is specified according to an EpiCore CDM specification template. This provides easy documentation and integrates with an R-package called EpiCoreAssistant, which provides quality control tools for testing the compliance of a CDM instance with the EpiCore specification. In the event that a project requires customization of the CDM, this is easily implemented in the template and testing. A step-by-step description is presented, demonstrating the steps involved in a typical CDM-based collaborative pharmacoepidemiological study using the EpiCore CDM. Conclusions: We present the EpiCore CDM, a specification template and an R package that offers a simple framework for improved workflows, standardizations and collaboration, focused on Scandinavian pharmacoepidemiological studies and with relevance for a broad palette of register-based health care researchers.