National Health Insurance Research Database (NHIRD)

The National Health Insurance Research Database (NHIRD) in Taiwan is a population-level data source, covering approximately 23 million individuals, accounting for 99.9% of the Taiwanese population. The NHIRD contains demographic information and medical claims data for a wide range of healthcare services, including records from outpatient visits, emergency department visits, hospitalizations, procedures, and prescriptions. It helps construct longitudinal histories, making it feasible for cohort study designs. It can be linked to various other national health-related databases, including Death Registry, the Taiwan Cancer Registry Database, the Taiwan Biobank, Birth Certificates Application (BCA) database, and Registry of Catastrophic Illness Patients, etc. To ensure patient privacy, personal identification numbers are encrypted and replaced with unique, anonymous identifiers. These anonymous identifiers are then used as linkage keys to connect data across multiple databases. The integration of multiple databases enhances the NHIRD’s utility as a comprehensive real-world resource for diverse longitudinal studies and provides extensive insights into public health trends across Taiwan.