Invitation variables

Target population 

The target population are those people of eligible age according to the programme policy residing in the area designated to be served by the screening programme. 

Eligible population 

The eligible population are those people in the target population who fulfil the eligibility criteria specified in the programme policy. 

Invited 

The invited are those members of the eligible population who have received an invitation for screening according to the programme policy/process; e.g. invited by mail, by primary care practitioner. N.B. Not all invitations sent may be received. 

Process variables of primary screening and follow up 

Process variables in screening with the faecal occult blood test (FOBT) and other in vitro tests 

The following process variables are described in the context of screening with faecal occult blood testing because FOBT is the only screening test currently recommended by the EU. In principle, the same definitions apply to other in vitro tests. It is recommended that the type of test used for screening is indicated when reporting data 

Screened/tested 

The group of screened or tested participants are those who have used and returned an FOBT irrespective of the result. This includes people with inadequate/incomplete results. Note that each person is counted once regardless of the number of tests performed. 

Inadequate test 

An inadequate FOBT is a test returned by a participant, the results of which cannot be reliably determined  The quality is insufficient for processing and the test cannot be used for recording a result according to the programme policy.  

Positive test 

A positive i.e. abnormal FOBT result is a result based on the last adequate test that according to the programme policy leads directly to referral to follow-up colonoscopy. 

 Referral to follow-up colonoscopy

This variable refers to participants with a positive FOBT who require an appointment for follow-up colonoscopy. Ideally all participants with positive FOBTs would be referred to follow-up colonoscopy.  

Variables in endoscopic screening 

The following process variables are described in the context of CRC screening in which either flexible sigmoidoscopy (FS) or colonoscopy (CS) is used as the primary screening test.

Screened

 The group of screened participants comprises those people who have attended the FS or CS screening examination, irrespective of the result. This includes people with inadequate/incomplete results. Note that each person is counted once regardless of the number of exams performed.  

 Inadequate test 

This group comprises those participants who attended the FS or CS screening examination, the results of which could not be interpreted because of inadequate preparation, and who do not have an adequate screening FS or CS in the reporting period. In such cases a new screening examination should be performed. 

Positive test 

A positive i.e. abnormal screening FS or CS is one resulting either directly in diagnosis of cancer or removal of an adenoma or other lesion, or in referral for further investigation according to the programme policy 

Referral to follow-up colonoscopy 

Included in this group are the participants with a positive screening FS or CS who require a medical appointment for follow-up colonoscopy

Referral to surgery or tertiary endoscopy 

This group of participants includes those who require an appointment for surgery or tertiary endoscopy for removal of challenging lesions following a positive screening FS or CS (or as a consequence of follow-up colonoscopy after primary screening with FS or CS). 

Severe complications requiring hospitalisation 

A very small number of participants will develop severe complications such as hospitalisation within 30 days due to serious haemorrhage involving transfusion, or due to perforation, vagal syndrome or peritonitis-like syndrome as a consequence of primary screening with FS or CS (or as a consequence of follow-up colonoscopy for any primary screening test). 

30-day mortality 

In a much smaller number of participants than those experiencing severe complications requiring hospitalisation, death may occur within 30 days after having undergone primary screening with FS or CS or follow-up colonoscopy, whether diagnostic or therapeutic, for any screening test. If the death is attributed to complications caused by the endoscopy, the participant should be counted in this group.