Follow-up colonoscopy compliance rate

In the RCTs using gFOBT, colonoscopy compliance rates range from 73% to 95%; in population programmes rates between 88% and 92% have been reported.

N people having attended a colonoscopy examination during the time frame* 

N people presenting with a positive screening test and referred during the time frame* 

* equal to the defined screening interval or reporting period

Follow-up colonoscopy outcome, detection rates 

A table should be made to present colonoscopy 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 advanced cancers.

 The above colonoscopy indicators are essential programme indicators of efficacy. 

Completion of follow-up colonoscopy after FOBT 

In the event of more than one detected lesion in a person where it is not possible to determine difference in prognosis, then the lesion requiring the most invasive procedure should be recorded

Detection rates of FOBT screening programme 

 Lesion detection rate 

The lesion detection rate is reported in % and is defined as the proportion of participants with at least one detected lesion among those adequately tested during the respective time frame. 

N people with at least one detected lesion during the time frame* 

N people adequately tested during the time frame* 

* equal to the defined screening interval or reporting period

 Adenoma detection rate  

The adenoma detection rate is reported per 1 000 (‰) and is defined as the proportion of participants with at least one detected adenoma among those adequately tested during the respective time frame.

N people with at least one detected advanced adenoma during the time frame *

 N people adequately tested during the time frame*

 * equal to the defined screening interval or reporting period  

 Cancer detection rate 

Detection rates for cancers and adenomas observed in population-based programmes using FOBT. Cancer detection rates range from 1.2‰ to 9.5‰ at the first round, with lower rates at subsequent rounds. Detection rates of all adenomas range from 5.2‰ to 22.3‰ at the first round, with lower rates at subsequent rounds. (However some studies report only advanced or high-risk adenomas.)  

N people with at least one detected cancer during the time frame * 

N people adequately tested during the time frame* 

* equal to the defined screening interval or reporting period  

 Stage of screen-detected cancers 

The stage distribution of screen-detected cancers should be reported by screening round, age and gender. In the RCTs using only gFOBT, the proportion of screen-detected cancers that were Dukes Stage A ranged from 26% to 36%