The majority of the HOI definitions can be implemented with Regularized Identification of Cohorts (RICO). RICO is a procedure that standardizes patient cohort selection. To create HOIs, RICO is employed using cohort definitions that are created using criteria that are specified input parameters. Patients meeting the criteria are selected from the common data model. RICO is available only in OMOP CDM v2 format.
The majority of HOI definitions can be implemented using RICO. Two exceptions are the "Acute Myocardial Infarction Definition #4" and the "Mortality after MI Definition #4", which both involve application of the American College of Cardiology definition that includes a complicated set of criteria about troponin, CK, and EKG results. Another exception is Hip Fracture Definition #3, which involves text evidence from radiology reports which is not available for development and testing within the IMEDS Research Lab. An implementation of this definition should be undertaken if the data source supports this kind of information.