title: Colonoscopic evaluation of immunochemical fecal occult blood test for detection of colorectal neoplasia.
abstract: OBJECTIVE
  This study was carried out to assess the validity of three testing methods of immunochemical occult blood according to the number of collection times as a means for colorectal cancer screening.
  
  
  METHODS
  Four thousand six hundred and eleven asymptomatic individuals, who received both an immunochemical occult blood test with a three-day method and colonoscopy during a medical checkup, served as subjects for this study. For evaluation of the desirable number of sampling times, we used the results of the first day for the 1-day method, the results of the first and second days for the 2-day method, and the results of three-consecutive days for the 3-day method. Sensitivities and specificities of these three testing methods were evaluated.
  
  
  RESULTS
  Sensitivities and specificities for colorectal cancer were calculated to be 56% and 97% for the 1-day method, 83% and 96% for the 2-day method, and 89% and 94% for the 3-day method, respectively, showing a significant difference in sensitivity between the 1-day and the 2-day methods, as well as the 3-day method (p < 0.01), and in specificity between the 1-day as well as the 2-day and 3-day methods (p < 0.05).
  
  
  CONCLUSIONS
  These findings indicate that the immunochemical fecal occult blood test is useful for the diagnosis of colorectal cancer, and that 2-day testing is recommended as a means of screening for colorectal cancer.
authors.affiliation: Department of Public Health, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakama
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
authors.forename: N
authors.initials: N
authors.lastname: Kamijo
authors.forename: T
authors.initials: T
authors.lastname: Li
authors.forename: N
authors.initials: N
authors.lastname: Wei
authors.forename: A S
authors.initials: AS
authors.lastname: Fattah
authors.forename: B
authors.initials: B
authors.lastname: Zhang
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000328:Adult; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D005069:Evaluation Studies as Topic; D006801:Humans; D009780:Occult Blood; D012680:Sensitivity and Specificity