title: Validity of fecal occult blood test in the national cancer screening program, Korea.
abstract: OBJECTIVE
  The aims of the current study were to assess the validity of the fecal occult blood test (FOBT) in an organized screening setting in Korea and to determine factors associated with FOBT validity, such as screening round, age group, and anatomical location of the cancer.
  
  
  METHODS
  Study participants were those who were 50 years and older who received an FOBT through the National Cancer Screening Program between 2004 and 2007. Colorectal cancer diagnoses were ascertained through linkage with the Korean National Cancer Incidence Database. The positivity rate, colorectal cancer detection rate, interval cancer rate, sensitivity, specificity, and positive predictive value of the FOBT were calculated.
  
  
  RESULTS
  A total of 2,193,093 tests were included in the analysis. Overall, the sensitivity of the FOBT for colorectal cancer was 59.7% for the first round and 56.1% for the subsequent round. Sensitivity was highest for distal colon cancer (65.9%) in the first round, and for rectal cancer (58.4%) for the subsequent round. The sensitivity and positive predictive value of the FOBT generally improved between 2004 and 2008.
  
  
  CONCLUSIONS
  The FOBT showed reasonable validity in an organized screening setting, and the validity of the FOBT varied by screening round, anatomical location, and screening year.
authors.affiliation: Molecular Epidemiology Branch, Research Institute, National Cancer Center, Goyang-si, Korea ; Cancer Registration & Statistics Branch, National Cancer Control Institute, National Cancer Center, Goyang-si, Korea.
authors.forename: Aesun
authors.initials: A
authors.lastname: Shin
authors.forename: Kui Son
authors.initials: KS
authors.lastname: Choi
authors.forename: Jae Kwan
authors.initials: JK
authors.lastname: Jun
authors.forename: Dai Keun
authors.initials: DK
authors.lastname: Noh
authors.forename: Mina
authors.initials: M
authors.lastname: Suh
authors.forename: Kyu-Won
authors.initials: KW
authors.lastname: Jung
authors.forename: Byung Chang
authors.initials: BC
authors.lastname: Kim
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Oh
authors.forename: Eun-Cheol
authors.initials: EC
authors.lastname: Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D005243:Feces; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009313:National Health Programs; D011237:Predictive Value of Tests; D056910:Republic of Korea