title: Establishment of external quality control program for hs-CRP and three-year follow-up of the performance for precision and accuracy.
abstract: OBJECTIVE
  We established an external quality control (QC) program for high-sensitivity C-reactive protein (hs-CRP) for a collaborative epidemiological study.
  
  
  METHODS
  External QC was performed 3 times in 3 years to follow hs-CRP performance for precision and accuracy.
  
  
  RESULTS
  For precision, the mean coefficient of variation (CV) of the internal QC by 9 laboratories was 2.2% and 1.9% in the 1st and 2nd tests, respectively. The mean CV of the external QC by 4 laboratories was 2.7% in the three tests. The CV of both the internal and external QC satisfied the acceptable range specified by the AHA/CDC Scientific Statement, CV < 10%. For accuracy, the mean values of the 1st external QC by 9 laboratories were set as the consensus value and the acceptable range was set to within +/- 10% from it. The mean accuracy by 9 laboratories was 0.51% in the 2nd external QC. The mean accuracy by 4 laboratories was - 0.37% in the 3rd external QC. These findings demonstrated that the initial consensus value was valid in the continued external QC, and hs-CRP was stable for 3 years.
  
  
  CONCLUSIONS
  We demonstrated both the precision and accuracy of hs-CRP by an external QC program applied for 3 years in a collaborative epidemiological study.
authors.affiliation: Osaka Medical Center for Health Science and Promotion, CRMLN Lipid Reference Laboratory, Osaka, Japan. xnakamura@kenkoukagaku.jp
authors.forename: Masakazu
authors.initials: M
authors.lastname: Nakamura
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sato
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimamoto
mesh_terms: D002097:C-Reactive Protein / Q000032:analysis / Q000592:standards*; D019963:Clinical Chemistry Tests / Q000592:standards*; D016021:Epidemiologic Studies; D006801:Humans; D015588:Observer Variation; D011786:Quality Control; D012016:Reference Values; D015203:Reproducibility of Results
chemical_list: D002097:C-Reactive Protein