Data source
This study analyzed the National Health Insurance Research Database (NHIRD) that contains the healthcare data of almost 99% of Taiwan’s entire population, approximately 23 million NHI beneficiaries. The database includes all insurance claims data, including outpatient visits, emergency visits, and hospitalizations. The Longitudinal Health Insurance Database, (LHID) is a subset of the NHIRD comprising one million individuals randomly sampled from the 23 million NHI beneficiaries for the period from 1999 to 2013.[16] The data of patients were de-identified prior to release to the users, in accordance with privacy protocols, and this study was approved by the Institutional Review Board of Chung Shan Medical University Hospital (IRB no. CS15134).