Cancer Care Ontario guaiac fecal occult blood test (FOBT) laboratory standards: evidentiary base and recommendations

Clin Biochem. 2008 Nov;41(16-17):1289-305. doi: 10.1016/j.clinbiochem.2008.08.069. Epub 2008 Aug 29.


Objectives: To evaluate the evidence concerning gFOBT kits and to develop gFOBT standards to be implemented by the Ontario Colorectal Cancer (CRC) Screening Program (the "Program").

Design and methods: We evaluated 3 aspects of gFOBT kits: 1) performance factors; 2) usability factors; and 3) laboratory factors. We obtained information from the published literature, other countries that use gFOBT, the internet, and gFOBT kit manufacturers' instructions.

Results: The Program should use a single brand of gFOBT kit with sensitivity > or =40% and specificity > or =95% for the detection of CRC in repeated testing. The Program should regularly monitor gFOBT performance. Participants should not restrict their diets except for eliminating vitamin C supplements and citrus fruits and juices for 3 days prior to and during stool collection; participants should not discontinue taking aspirin (ASA) or non-steroidal anti-inflammatory drugs (NSAIDs). The Program should use one or a limited number of labs; leak-proof envelopes should be used that protect samples during mailing; the lab should delay processing fecal samples for at least 48 h following stool collection; the lab should implement staff training and quality control protocols.

Conclusions: The Program should monitor and report on its performance according to these standards, and should continually assess new evidence related to CRC screening methods.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Chemistry, Clinical / standards*
  • Colorectal Neoplasms / diagnosis
  • Evidence-Based Medicine*
  • Guaiac*
  • Humans
  • Internet
  • Mass Screening
  • Middle Aged
  • Occult Blood*
  • Ontario
  • Predictive Value of Tests
  • Reagent Kits, Diagnostic / standards*
  • Reproducibility of Results
  • Sensitivity and Specificity


  • Reagent Kits, Diagnostic
  • Guaiac