title: Nationwide multicenter study aimed at the establishment of common reference intervals for standardized clinical laboratory tests in Japan.
abstract: BACKGROUND
  The Japanese Association of Medical Technologists (JAMT) sought to establish common reference intervals (RIs) applicable nationwide in Japan for 27 serum constituent analytes for which certified reference materials are available and nine analytes frequently measured in routine tests. More than 100 laboratories certified for metrological traceability collaborated in the recruitment, sampling, and measurement of analytes for the establishment of RIs. No previous attempt has been made to establish RIs by such a large number of laboratories. The allowable limits of trueness and intermediate precision based on the JAMT criteria were applied to the reference values measured by these laboratories, and measured values within the allowance limits were used to establish RIs.
  
  
  METHODS
  Reference individuals included 5748 healthy volunteers aged 18-65 years who were engaged in medical care-related work based on the CLSI guidelines. After secondary exclusion of individuals in whom abnormal values were detected in basic routine test items and adjustment for the distribution of age and gender, 3371 reference individuals were chosen in the parametric determination of RIs. Employing the three-level nested ANOVA, between-laboratory, -region, -sex, and -age variations were evaluated.
  
  
  RESULTS
  No significant difference was noted in between-region variations in any item. Results of ANOVA revealed between-sex and -age variations in 14 and 15 analytes, respectively. Based on these results of variation, RIs were established with and without partition by sex.
  
  
  CONCLUSIONS
  Since no between-region variation was detected in reference values among accuracy-certified core laboratories, RIs applicable nationwide were established.
authors.affiliation: Department of Clinical Laboratory Science, Tenri Health Care University Division, 80-1, Bessho, Tennri, Nara 632-0018, Japan. y-yama@tenriyorozu-u.ac.jp
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Shigemi
authors.initials: S
authors.lastname: Hosogaya
authors.forename: Susumu
authors.initials: S
authors.lastname: Osawa
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ichihara
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Onuma
authors.forename: Atsushi
authors.initials: A
authors.lastname: Saito
authors.forename: Kouji
authors.initials: K
authors.lastname: Banba
authors.forename: Hideo
authors.initials: H
authors.lastname: Araki
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Nagamine
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Shinohara
authors.forename: Gen
authors.initials: G
authors.lastname: Okada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Oguri
authors.forename: Satoko
authors.initials: S
authors.lastname: Gonaikawa
authors.forename: Miyuki
authors.initials: M
authors.lastname: Iwagami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019411:Clinical Laboratory Techniques / Q000592:standards*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D012016:Reference Values; D055815:Young Adult