Rich clinical insights into real-world treatment patterns and healthcare utilization are within reach. Closed administrative claims data are routinely used in HEOR research to assess areas such as Patient Adherence, Health Care Resource Utilization, and the Patient Journey. The nature of claims data ensures that activities associated with a patient’s care are captured, but analyses of the data are limited to information recorded for the purposes of reimbursement – e.g., patient demographics, diagnosis and procedure codes, and pharmacy fills. This can restrict the insights to what occurred, with limited visibility into clinical information that may have influenced treatment decisions and healthcare utilization. Analyses of patient behavior and outcomes also are limited to the population as a whole – or segmented by variables available in, or proxy clinical measures derived from, claims data. Patient registries are purpose-built to capture clinical measures directly from physicians and patients including disease duration for chronic illnesses and disease activity based on validated composite outcome measures incorporating physical exam findings and patient reported outcomes, but may not reflect the full spectrum of healthcare encounters. Linking claims data with the clinical data available in patient registry data provides an additional level of depth that is not typically available today. This symposium will focus on the benefits that can be gained from leveraging multiple linked data sources. Panelists will discuss the attributes of both data sources and the power of the combined data, including specific examples of how additional insights have been derived from the unique combination of claims and patient registry data.