title: Background and data configuration process of a nationwide population-based study using the korean national health insurance system.
abstract: BACKGROUND
  The National Health Insurance Service (NHIS) recently signed an agreement to provide limited open access to the databases within the Korean Diabetes Association for the benefit of Korean subjects with diabetes. Here, we present the history, structure, contents, and way to use data procurement in the Korean National Health Insurance (NHI) system for the benefit of Korean researchers.
  
  
  METHODS
  The NHIS in Korea is a single-payer program and is mandatory for all residents in Korea. The three main healthcare programs of the NHI, Medical Aid, and long-term care insurance (LTCI) provide 100% coverage for the Korean population. The NHIS in Korea has adopted a fee-for-service system to pay health providers. Researchers can obtain health information from the four databases of the insured that contain data on health insurance claims, health check-ups and LTCI.
  
  
  RESULTS
  Metabolic disease as chronic disease is increasing with aging society. NHIS data is based on mandatory, serial population data, so, this might show the time course of disease and predict some disease progress, and also be used in primary and secondary prevention of disease after data mining.
  
  
  CONCLUSIONS
  The NHIS database represents the entire Korean population and can be used as a population-based database. The integrated information technology of the NHIS database makes it a world-leading population-based epidemiology and disease research platform.
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea. ; Department of Medicine, Yonsei University Graduate School of Medicine, Seoul, Korea.
authors.forename: Sun Ok
authors.initials: SO
authors.lastname: Song
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chang Hee
authors.initials: CH
authors.lastname: Jung
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
authors.forename: Young Duk
authors.initials: YD
authors.lastname: Song
authors.affiliation: Department of Endocrinology and Metabolism, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Cheol-Young
authors.initials: CY
authors.lastname: Park
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Hyuk-Sang
authors.initials: HS
authors.lastname: Kwon
authors.affiliation: Department of Medicine, Yonsei University Graduate School of Medicine, Seoul, Korea. ; Division of Endocrinology and Metabolism, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Cha
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Joong-Yeol
authors.initials: JY
authors.lastname: Park
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Ki-Up
authors.initials: KU
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Inje University Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea.
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Ko
authors.affiliation: Department of Medicine, Yonsei University Graduate School of Medicine, Seoul, Korea. ; Division of Endocrinology and Metabolism, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Byung-Wan
authors.initials: BW
authors.lastname: Lee
keywords: Korea; National Health Insurance; National Health Insurance Service; Population-based data