The objective of this investigation was 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").

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

The Program should use a single brand of gFOBT kit with sensitivity >40% and specificity >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 three 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 hours following stool collection; the lab should implement staff training and quality control protocols.

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