title: Effect of Accreditation on Accuracy of Diagnostic Tests in Medical Laboratories.
abstract: BACKGROUND
  Medical laboratories play a central role in health care. Many laboratories are taking a more focused and stringent approach to quality system management. In Korea, laboratory standardization efforts undertaken by the Korean Laboratory Accreditation Program (KLAP) and the Korean External Quality Assessment Scheme (KEQAS) may have facilitated an improvement in laboratory performance, but there are no fundamental studies demonstrating that laboratory standardization is effective. We analyzed the results of the KEQAS to identify significant differences between laboratories with or without KLAP and to determine the impact of laboratory standardization on the accuracy of diagnostic tests.
  
  
  METHODS
  We analyzed KEQAS participant data on clinical chemistry tests such as albumin, ALT, AST, and glucose from 2010 to 2013. As a statistical parameter to assess performance bias between laboratories, we compared 4-yr variance index score (VIS) between the two groups with or without KLAP.
  
  
  RESULTS
  Compared with the group without KLAP, the group with KLAP exhibited significantly lower geometric means of 4-yr VIS for all clinical chemistry tests (P<0.0001); this difference justified a high level of confidence in standardized services provided by accredited laboratories. Confidence intervals for the mean of each test in the two groups (accredited and non-accredited) did not overlap, suggesting that the means of the groups are significantly different.
  
  
  CONCLUSIONS
  These results confirmed that practice standardization is strongly associated with the accuracy of test results. Our study emphasizes the necessity of establishing a system for standardization of diagnostic testing.
authors.affiliation: Department of Laboratory Medicine and Genetics, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea.
authors.forename: Mi Ae
authors.initials: MA
authors.lastname: Jang
authors.affiliation: Department of Laboratory Medicine, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine, Cheonan, Korea.
authors.forename: Young Ahn
authors.initials: YA
authors.lastname: Yoon
authors.affiliation: Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors.forename: Junghan
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Won Ki
authors.initials: WK
authors.lastname: Min
authors.affiliation: Clinical Trial Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Ji Sung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine and Genetics, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea. lywmd@schmc.ac.kr.
authors.forename: Yong Wha
authors.initials: YW
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine and Genetics, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea. cecilia@schmc.ac.kr.
authors.forename: You Kyoung
authors.initials: YK
authors.lastname: Lee
mesh_terms: D000068:Accreditation; D000410:Alanine Transaminase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D019963:Clinical Chemistry Tests; D003955:Diagnostic Tests, Routine / Q000592:standards*; D007755:Laboratories, Hospital / Q000592:standards*; D011786:Quality Control; D056910:Republic of Korea; D012709:Serum Albumin / Q000032:analysis
chemical_list: D012709:Serum Albumin; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase
keywords: Quality assurance; Quality system management; Standardization, Accuracy; The Korean Association of External Quality Assessment Service; The Korean External Quality Assessment Scheme