Abstract
The Korea National Disability Registration System (KNDRS) was established in 1989 to provide social welfare benefits based on predefined criteria for disability registration and an objective medical assessment using a disability grading system. Disability registration requires (1) a medical examination by a qualified specialist physician and (2) a medical advisory meeting to review the degree of disability. Medical institutions and specialists for the diagnosis of disabilities are legally stipulated, and medical records for a specified period are required to support the diagnosis. The number of disability types has gradually expanded, and 15 disability types have been legally defined. As of 2021, 2.645 million people were registered as disabled, accounting for approximately 5.1% of the total population. Among the 15 disability types, disabilities of the extremities account for the largest proportion (45.1%). Previous studies have investigated the epidemiology of disabilities using data from the KNDRS, combined predominantly with data from the National Health Insurance Research Database (NHIRD). Korea has a mandatory public health insurance system that covers the entire Korean population, and the National Health Insurance Services manages all eligibility information, including disability types and severity ratings. In short, the KNDRS-NHIRD is a significant data resource for research on the epidemiology of disabilities.