“…The data used in this study were obtained from a 2006 National Health Insurance (NHI) cohort data set comprising a sample corresponding to 2.2% (n = 1,000,000) of the Korean population (N = 48,222,537 in 2006); it was collected by stratified random sampling according to sex, age, region, types of insurance, and insurance premium. Follow-up examinations were held from 2002 to 2015 [18]. The data set included information on patient characteristics such as demographic and socioeconomic factors, healthcare utilization and treatment details, medical check-ups, and medical institution characteristics.…”