title: Immunochemical faecal occult blood tests in primary care and the risk of delay in the diagnosis of colorectal cancer.
abstract: OBJECTIVE
  To evaluate the value, risks, and shortcomings of immunochemical faecal occult blood tests (iFOBTs) in the diagnosis of colorectal cancer (CRC) and adenomas with high-grade dysplasia (HGD) in patients initially presenting to primary care.
  
  
  METHODS
  A retrospective population-based study.
  
  
  METHODS
  All 495 cases of CRC and adenomas with HGD diagnosed in the county of Jämtland, Sweden from 2005 to 2009.
  
  
  RESULTS
  Of 495 patients 323 (65%) initially presented to primary care. IFOBTs were performed in 215 of 323 (67%) patients. The sensitivity of iFOBT for CRC and adenomas with HGD was 88% (83% when patients with a history of rectal bleeding were excluded). Of 34 patients with anaemia found en passant, 10 had negative iFOBTs. Time to diagnosis was longer for patients with negative iFOBTs (p < 0.0005).
  
  
  CONCLUSIONS
  IFOBT might be helpful in selecting which patients to refer for colonoscopy. However, iFOBT has a limited sensitivity as a diagnostic test for CRC and adenomas with HGD. Relying only on iFOBT for colonoscopy referral could delay diagnosis, especially for patients with anaemia found en passant.
authors.affiliation: Department of Public Health and Clinical Medicine, Unit of Clinical Research Centre - Östersund, Umeå University , Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Högberg
authors.forename: Pontus
authors.initials: P
authors.lastname: Karling
authors.forename: Jörgen
authors.initials: J
authors.lastname: Rutegård
authors.forename: Mikael
authors.initials: M
authors.lastname: Lilja
authors.forename: Thomas
authors.initials: T
authors.lastname: Ljung
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D057210:Delayed Diagnosis / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007120:Immunochemistry; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009780:Occult Blood; D011320:Primary Health Care / Q000379:methods*; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013548:Sweden