Programme outcome variables

The following outcome variables apply to CRC screening performed with any of the currently available primary screening tests.

Follow-up colonoscopy  

Participants in the group on which diagnostic or therapeutic colonoscopy4 has been performed to follow-up primary screening according to programme policy include participants, the screening endoscopy of which was inadequate or incomplete. Note that each person is counted once regardless of the number of follow-up colonoscopies that were performed. Where more than one colonoscopy or other follow-up investigation is performed, the reported result should be that of the complete diagnostic or therapeutic work-up.

Lesions 

Any lesion removed or biopsied at endoscopy or surgery (whether or not they were diagnosed as adenomas) should be recorded.  

Adenomas 

Pathological specimens removed at endoscopy or surgery that have been reported by a pathologist to be adenomatous should be recorded.

Advanced adenoma

 If it is not possible to collect such details for organisational reasons, the programme should at least focus on collecting and reporting data on adenomas 10 mm in size 

Cancers

 Colorectal cancer diagnosed by the screening programme, or diagnosed as a direct result of participating in the screening programme 

 List of recommended data tables to be produced by CRC screening programmes

1. Targeted 

2. Eligible 

3. Invited 

4. Screened/tested at first screening and at subsequent screening episodes 

5. Inadequate tests 

6. Positive test or screening 

7. Follow-up colonoscopy examination attended (diagnostic assessment and/or treatment) 

8. Negative follow-up colonoscopy examination (diagnostic assessment and/or treatment) 

9. Positive follow-up colonoscopy examination (diagnostic assessment and/or treatment) 

10. Lesion detected (at least one) 

11. Adenoma detected (at least one) 

12. Non-advanced adenoma detected (at least one) 

13. Advanced/high-risk adenoma detected (at least one) 

14. Cancer detected by stage 

Early performance indicators 

Several rounds of screening are required before the impact of a screening programme on CRC mortality in the target population can be measured. Early performance indicators using standard definitions must therefore be used early in the lifetime of a screening programme to measure the quality of the screening process and to assess its potential longer-term impact. The accumulating experience in piloting and implementing population-based screening programmes provides an evidence base that can be used to establish and refine standards and set performance targets.

Factors affecting performance indicators 

 Coverage and uptake, i.e. participation, are organisational parameters that apply to CRC screening programmes using any kind of primary screening test. They have a substantial impact on the potential effectiveness of any screening programme because they reflect the degree to which the population is exposed to the screening intervention. Coverage and uptake in turn will be affected by the age and gender distribution of the target population due to differential uptake rates. Screening performance indicators will be affected by the age and gender distribution of the population screened due to variation in underlying incidence of disease.