Table 2.
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 |
Irrespective of age, ethnicity, income or geographical location.
The 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.
Participation 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.
In 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.
The 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.
This 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.