Using Electronic Health Records in Longitudinal Studies

Electronic health records (EHRs) provide rich data on many domains not routinely available in other data, as such, they are a promising source to study changes in health outcomes using longitudinal study designs (eg, cohort studies, natural experiments, etc.). Yet, patient attrition rates in these data are unknown.The objective of this study was to estimate overall and among adults with diabetes or hypertension: (1) patient attrition over a...