Table 2.

Trade-offs involved in FOBT cancer screening programmes with inadequate funding

Characteristic	Features	More funding/resources	Less funding/resources	Optimal features
Frequency	N/A	More often	Less often	At least biennial8
Population coverage	Invited age range	More people in the appropriate age range	Less people in the appropriate age range	50 to 74 or 75 year olds16–17
	Participation rates	Maximize for all people, including population sub-groupsa to ensure equity of access	Aim for 60% but may be a one-size fits all programme	Minimum of 60% of the unscreened populationb, maximising equity of access for population sub-groupsc
	Speed of implementation	Faster	Slower	As fast as possible, without decreasing quality and increasing waiting timesd
Quality of test	Type of test	Most accurate	Most affordable	Quantitative immunochemical FOBT18– 22
	Test positivity rate	Higher	Lower	Between 5–8% to minimize missed cancers and advanced adenomasd
	Positive predictive value	Higher	Lower	The combined PPVs for cancer and advanced adenomas should be at least 20% to minimize unnecessary investigationsd
	Screening algorithm	Minimizes re-testing and inconvenience	May involve up to three FOBTs	FOBT with actionable result after one test (positive or negative), and no dietary or medication restrictionsd
Programme model	Invitation register	Able to exclude in advance those not suitable for FOBT screening	General invitation to all in the target age group	Utilizes existing medical information in targeting inviteesd
	Funding	Single funder	Multiple funders	Single funder to provide adequate levels of funding to maximize benefits and minimize harms, while avoiding cost-shiftingd
	Provider	Designated provider	Usual cared	Designated providers to set minimum quality standards and mandate return of data to registerd,e
Quality of follow-up of positive test	Who by?	Staff with bowel cancer screening knowledge and expertise	Usual care	Staff with specific expertise to provide tailored advice on benefits and harms and procedural matters, increase adherence to follow-up and ensure safety by assessing pre-colonoscopy riskd
	Waiting times	Shorter	Longer	Within 28 days from positive test to colonoscopyf
Quality of colonoscopy	Certification of colonoscopists	National certification with minimal standards for training	No minimum standards for training	Specialized training to ensure consistency across regions and maximize quality and safetyd
	Accreditation of colonoscopy facility	National accreditation with minimal standards for facilities	No minimum standards for facilities	National accreditation standards to ensure consistency across regions and maximize quality and safetyd
Quality of data collection	Return of data	Specific IT systems created for the bowel cancer screening programmes	Usual IT systems	Specialized IT systems to maximize quantity and quality of data returned to registerd
	Reporting of data	Regular internal and external reporting	Some internal but less external reporting	At least quarterly internal and annual external reporting to allow for continuing programme evaluationd

^aIrrespective of age, ethnicity, income or geographical location.

^bThe idea of setting participation ‘targets’ is contentious as it may lead to people being encouraged to be screened, rather than them making their own genuinely informed choice about whether to be screened or not. Nevertheless, participation rates are used as a de facto measure of a screening program’s success. A participation rate close to 60% was achieved in the Nottingham RCT²³ and this has become an unofficial ‘acceptable’ or target rate. The NHS Quality Improvement Scotland (QIS) standard for bowel screening uptake is 60%.¹³ This figure was also used by English researchers to model potential population-based bowel cancer screening programmes²⁴ and representatives from all four UK screening programmes were keen to establish participation rates at around this level or higher [UK02, UK05, UK11, UK13], although there is evidence that high participation in bowel cancer screening programmes is not necessary to achieve cost-effectiveness.²⁵ In Australia, where there is a large amount of opportunistic bowel cancer screening outside the programme (mainly via colonoscopy but also through some independent FOBT programmes such as the one run by Rotary) a participation rate of 60% may be more unrealistic.

^cParticipation in both the UK⁵ and Australian⁶ pilots varied according to population sub-groups, and this was identified as an issue that needed to be addressed.

^dIn our considered opinion. These ideal features are based on what seems to work best and/or appears to have the best clinical outcomes, in the absence of definitive evidence.

^eThe usual care model, while less expensive than a designated provider model, may also be chosen on equity, rather than cost grounds. It ensures all people requiring colonoscopy, whether screen-detected or not, have access to the same standard of care.

^fThis is the ideal maximum waiting time specified in the English, Welsh and Northern Irish programmes. It is not achieved in all areas of these countries.