Data Source
The data for this study were obtained from the National Health Insurance Research Database (NHIRD). The Taiwan government launched a National Health Insurance Program (NHIP) in 1995. NHIP provides comprehensive medical care services to nearly all (99%) residents in Taiwan. The health information, which includes claims of the inpatients and outpatients and medications prescribed, was recorded in the NHIRD. For patient privacy, the data were deidentified. In this cohort study, we used all inpatient data from 2000 to 2013.