Table 1.

Types of interventions

Category	n	Description
Behavior priming	6	Where the text content within printed materials accompanying a kit were manipulated to prime or encourage screening behavior (e.g., priming regret, implying advocacy from others, setting intentions).
Added print materials	11	Where extra information in print format was added to the standard kit (e.g., educational booklets on CRC, or enhanced instructions).
Incentive	1	Where participants were offered an incentive to return completed kits.
Advance notification	4	Where letters notifying participants of the kit arrival were sent out prior to the kit.
Outdoor advertising	1	The placement of billboards or posters in public areas.
Simplified test	17	Where the FOB testing procedure itself was simplified or enhanced for the user (e.g., removing dietary restrictions or including collection papers).
Telephone contact	4	Where participants were contacted by telephone for the reminder and/or instruction purposes.
GP endorsement	6	Where the kit invitation included a letter from the participant’s GP or GP practice.
Digital reminder	3	Where participants are sent either an SMS or email reminder to complete and return FOBT kit