Table 5.

Summary of the results from ‘ recruitment ’ studies included in the review (n = 58 studies)

Barriers	Strategies
Lack of trust in research/research team or uncertainty regarding how survey results will be used	• Community-driven research [44,56,70,71,75,114] and community partnerships [18,28,75,77,78,80,93,94],[100,101,113,115].
Fear of authority	• Peer or known recruiters [21,28,40,74,82,96,113,115],[105,121,123,124].
Perceived harms of research	• Sensitive wording: “study”, “conversation” and “dialogue” instead of “investigation”, “research” and “interview” [26,47,60,92].
Mistreatment and exploitation	• Use of ‘hand-written’ envelopes (vs. printed) [106]*
No benefits for participation (i.e., ‘fly in, fly out’ research)	• Enlisting community leaders (60, 113,114,115,127].
	• Commitment to “give back” to the community through sustainable interventions [31,94,114,115] or reciprocal benefits [64,74,101] or if not resourced to provide intervention, provide links to services [118] or minimal intervention controls [44].
	• Shared data ownership and publication [114,118]
	• Gifts with project logo [18,30,92-94,118,127] and incentives [42,47,119,123].
	• Thank you and award ceremonies and project feedback [114,118].
	• Emphasising potential benefits [74].
	• Improved communication and culturally relevant education materials [32].
Lack of education/awareness re research or health promotion/low health literacy, difficulties understanding consent and what the study is about	• Utilising appropriate media (print vs. TV vs. online) [18,25,41,56,65,85,87,119]; mass media [61,62,72,81] or social marketing strategies [37,47,72,83].
	• Provision of participant feedback regarding the research outcomes [30,115].
	• Public information sessions [47,116].
	• Simplified consent forms – large font, plain language, shorter sentences, in respondents language, ensure translation makes sense, wide margins, shorter paragraphs [45,86,114].
	• Bilingual recruiters and materials [18,56,85,92,104,112]
Cultural beliefs, gender roles/age related issues	• Cultural competence skills of research team/well trained research staff [16,22,30,56,63,101,104,118]
	• Culturally targeted media [41,72,113,115]
	• Mindful different cultures require different strategies [16,43,63,67,93,94,103,118],[125].
	• Recruitment strategies adapted to local conditions for a community-specific approach [16,63,85,86,93,113,125].
Gatekeepers (therefore patients/community are not aware of research): doctors or nurses who do not approach minority participants, high turnover of staff limits relationships	• Work with gatekeepers [14,15,100,103,123], employ locals as staff [22,55,93,113,118].
Doctor poor communication methods	• Ensure appropriate authorities are consulted [113,114].
Rigid exclusive eligibility criteria	• Patient education materials [32].
	• Financial incentives for recruitment partners to employ support staff to recruit [32,44,143,125].
	• Flexible eligibility criteria [35,50].
Stigma/fear of exposure	• Online focus group and interview research [51,52] or video recruitment [46].
	• Community advisory group [28,47,100,113,118].
Low response rates in general	• Multiple (>6) contact attempts [40,66,81,99].
	• Toll-free number [61,70] or follow-up a mail survey with a telephone survey of non-responders [106].
	• Through doctors/health services [85,93,103,123].
	• Outreach/home visits [21,25,99].
	• Text messaging [65].
	• Incentives [18,30,40,42]*,[43]*,[70,81,92-94,123,127].
	• Recruitment letters: An advance letter (prior to a mailed survey) [36]* or culturally framed letter [43]*.
	• Two stage recruitment 1) to a low commitment survey then 2) to the trial [83].
	• Assistance with transport or child care [30,73].
	• Shorter surveys [106].
	• Develop a registry with interested people [25].

*Indicates good evidence from randomised controlled trial (see also Table 1).