title: Diagnostic value of occult fecal blood testing for colorectal cancer screening.
abstract: OBJECTIVE
  To evaluate the diagnostic value of occult fecal blood testing in mass colorectal cancer screening.
  
  
  METHODS
  A reverse passive hemagglutination reaction fecal occult blood test (RPHA-FOBT) and colorectal cancer risk factor quantitative method were used as preliminary screening for colorectal cancer. A 60-cm fiber optic colonoscopy was used to validate the preliminary screen and was used to detect colorectal cancer in a community of 75813 subjects.
  
  
  RESULTS
  Compared to the 60-cm fiber optic colonoscopy as a standard reference, FOBT has a sensitivity of 41.9%, specificity of 95.8%, Youden's index of 0.38, and positive predictive value of 0.68%. These results increased with subject age from the first detection. A 3-year follow up in the target mass showed that all new cases had initially been FOBT-negative.
  
  
  CONCLUSIONS
  The value of FOBT as an indicator of colorectal cancer in mass screening is limited.
authors.affiliation: Kun Chen, Deng-Ao Jiao, Yang Zhang, Department of Epidemiology, Zhejiang Medical University, Hangzhou 310031, Zhejiang Province, China.
authors.forename: K
authors.initials: K
authors.lastname: Chen
authors.affiliation: Kun Chen, Deng-Ao Jiao, Yang Zhang, Department of Epidemiology, Zhejiang Medical University, Hangzhou 310031, Zhejiang Province, China.
authors.forename: D A
authors.initials: DA
authors.lastname: Jiao
authors.affiliation: Kun Chen, Deng-Ao Jiao, Yang Zhang, Department of Epidemiology, Zhejiang Medical University, Hangzhou 310031, Zhejiang Province, China.
authors.forename: S
authors.initials: S
authors.lastname: Zheng
authors.affiliation: Kun Chen, Deng-Ao Jiao, Yang Zhang, Department of Epidemiology, Zhejiang Medical University, Hangzhou 310031, Zhejiang Province, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Kun Chen, Deng-Ao Jiao, Yang Zhang, Department of Epidemiology, Zhejiang Medical University, Hangzhou 310031, Zhejiang Province, China.
authors.forename: H
authors.initials: H
authors.lastname: Yu
authors.affiliation: Kun Chen, Deng-Ao Jiao, Yang Zhang, Department of Epidemiology, Zhejiang Medical University, Hangzhou 310031, Zhejiang Province, China.
authors.forename: Y C
authors.initials: YC
authors.lastname: Yuan
authors.affiliation: Kun Chen, Deng-Ao Jiao, Yang Zhang, Department of Epidemiology, Zhejiang Medical University, Hangzhou 310031, Zhejiang Province, China.
authors.forename: K Y
authors.initials: KY
authors.lastname: Yao
authors.affiliation: Kun Chen, Deng-Ao Jiao, Yang Zhang, Department of Epidemiology, Zhejiang Medical University, Hangzhou 310031, Zhejiang Province, China.
authors.forename: X Y
authors.initials: XY
authors.lastname: Ma
authors.affiliation: Kun Chen, Deng-Ao Jiao, Yang Zhang, Department of Epidemiology, Zhejiang Medical University, Hangzhou 310031, Zhejiang Province, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
keywords: Colonoscopy; Colorectal neoplasms/diagnosis; Mass screening; Occult blood; Risk factors