Outcomes with flexible sigmoidoscopy (FS) or colonoscopy (CS) as primary screening tests

Inadequate FS or CS rates

 An inadequate FS or CS occurs when the examination cannot be performed because of inadequatepreparation. 

N people with an inadequate FS or CS, respectively, during the time frame* 

N people screened with FS or CS, respectively, during the time frame* 

* equal to the defined screening interval or reporting period

Complete FS or CS rates 

FS and CS examinations are considered complete when conducted under adequate bowel preparation and with visualisation of the colon beyond the sigmoid-descending-colon-junction (FS), or the caecum (CS). 

N people with complete FS or CS, respectively* 

N people screened with FS or CS, respectively, under adequate bowel preparation 

* equal to the defined screening interval or reporting period

Endoscopy outcome tables

A table should be made to present the screening endoscopy results by gender and age: 

• Negative, (defined as no identified lesions, adenomas or cancers); 
• Presence of adenomas of any size; 
• Presence of non-advanced adenomas; 
• Presence of advanced adenomas; and 
• Presence of cancers. 

A similar table should be made to present the endoscopic results of follow-up colonoscopy in participants with positive FS or CS screening exams who are referred to follow-up colonoscopy  

Positive FS or CS rate 

The positive FS rate reported in different studies depends on the definition used (for example whether removed lesions not requiring further surveillance are recorded as a positive result or a negative result).  Positive CS rates ranging from 20.4% to 53.8% have been reported from population studies (Lieberman et al. 2000; Shoenfeld et al. 2005; Regula et al. 2006). The latter rate was reported in a study with a high percentage of participants with a family history of CRC. 

N people with a positive FS or CS result, respectively, during the time frame * 

N people screened with FS or CS, respectively, during the time frame * 

* equal to the defined screening interval or reporting period 

Endoscopic complications of FS or CS screening programmes

The following complications are defined as serious: death within 30 days; or hospitalisation within 30 days due to serious haemorrhage involving transfusion, or due to perforation, vagal syndrome or peritonitis-like syndrome. All complications should be recorded as well as the respective cause, if discernible.

For any complication the rate is defined as the proportion of participants presenting with a complication among those having attended the respective type of endoscopic exam (FS or CS). Rates should be broken down by exams performed for primary screening and exams performed for follow-up of positive screening results. 

N people presenting with complication of FS or CS, respectively, during time frame* 

N people having attended the respective exam (FS or CS) during the time frame *

 * equal to the defined screening interval or reporting period