Table 1

The topics addressed in each of the principles established by the consensus process

Principle number	Topic
1	Desired outcome of CRC screening.
2	Screening is a multistep process.
3	A screening test identifies individuals with an increased likelihood of CRC and/or advanced precursor lesions.
4	Nature of precursor lesions most important to detect.
5	New biomarkers might detect lesions with a different natural history.
6	Outcomes to be estimated in a screening population.
7	Expectations of a new non-invasive test.
8	An adjustable test positivity threshold accommodates different programme goals.
9	Predicting value by paired comparison with a proven non-invasive screening test.
10	Evaluation proceeds through increasingly complex phases.
11	Accuracy required for evaluation in a screening population.
12	Analytical specifications, standards and performance.