Table 1.

Search terms and inclusion and exclusion criteria

Key word	Search terms
Boundary spanning (concept)	“boundary spann*” OR “boundary cross*” OR “community guide*” OR “community aide” OR “community organi?er*” OR intermediary OR broker OR bridge* OR connector OR “translation agent” OR networker OR promatora OR navigator*
Marginalised (population)	Marginali?ed. OR disadvantage* OR “hard to reach”
Health services (context)	Hospital* OR “primary care” OR “community health” OR “health organi?ation*” OR “health service*” OR healthcare
Inclusion criteria	Article type: research, discussion, review or scoping review Addressing all three conceptual areas: health; boundary spanning; marginalised population About boundary spanning between health setting and the community About use of boundary spanners from the community context not the institutional setting—i.e. from the community or with similar attributes to community being served Located in high-income countries (added as criteria at stage three)
Exclusion criteria	Not in English Not peer-reviewed Published before 2007 Outlining a study that had not yet commenced