PS1-44: Comparing Measures of Disease Frequency Between Population Denominator Methods Using Data in the Electronic Health Record

摘要

Background/AimsThe HMORN includes research centers that are part of integrated delivery systems where the clinical practice and insurance entities are independent (e.g., Geisinger, Marshfield) and where the primary care practice offers the larger population sample. Population denominators in these systems can be defined from insurance membership only, the primary care practice only (i.e., using electronic health records or EHR), or the overlap of the two (i.e., primary care patients may not be members of the insurance entity and visa versa). Methods for defining denominators and person-time for members of an insurance plan are well established. However, such methods have not been developed or validated for primary care practices using the EHR. The aim of this study was to use EHR data from a large primary care practice to derive measures of disease prevalence and incidence and to evaluate the validity of these measures using insurance claims data.