Abstract
Background
Members of vulnerable populations are underrepresented in research studies.
Objective
To evaluate and synthesize the evidence regarding interventions to enhance enrollment of vulnerable populations into health research studies.
Data sources
Studies were identified by searching MEDLINE, the Web of Science database, personal sources, hand searching of related journals, and article references. Studies that contained data on recruitment interventions for vulnerable populations (minority, underserved, poor, rural, urban, or inner city) and for which the parent study (study for which recruitment was taking place) was an intervention study were included. A total of 2,648 study titles were screened and 48 articles met inclusion criteria, representing 56 parent studies. Two investigators extracted data from each study.
Results
African Americans were the most frequently targeted population (82% of the studies), while 46% targeted Hispanics/Latinos. Many studies assessed 2 or more interventions, including social marketing (82% of studies), community outreach (80%), health system recruitment (52%), and referrals (28%). The methodologic rigor varied substantially. Only 40 studies (71%) incorporated a control group and 21% used statistical analysis to compare interventions. Social marketing, health system, and referral recruitment were each found to be the most successful intervention about 35–45% of the studies in which they were attempted, while community outreach was the most successful intervention in only 2 of 16 studies (13%) in which it was employed. People contacted as a result of social marketing were no less likely to enroll than people contacted through other mechanisms.
Conclusions
Further work with greater methodologic rigor is needed to identify evidence-based strategies for increasing minority enrollment in research studies; community outreach, as an isolated strategy, may be less successful than other strategies.


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Financial Support and Disclosure
Dr. Gross’s efforts were supported by Claude D. Pepper Older` Americans Independence Center at Yale (P30AG21342).
Potential Financial Conflicts of Interest
None disclosed.
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Medline search terms
1 | Clinical trials or randomized controlled trials or multicenter studies |
2 | African Americans or Hispanic Americans or African American Continental Ancestry Group or minority groups or social class or socioeconomic factors or poverty or medically underserved area or urban population |
3 | Patient selection or research subjects, and [(enrol$ or recruit$ or particip$ or enlist$ or attrit$ or retent$).mp. |
4 | interven$ or initiativ$ or method$ or strateg$ or increase$ or enhanc$).mp. |
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UyBico, S.J., Pavel, S. & Gross, C.P. Recruiting Vulnerable Populations into Research: A Systematic Review of Recruitment Interventions. J GEN INTERN MED 22, 852–863 (2007). https://doi.org/10.1007/s11606-007-0126-3
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DOI: https://doi.org/10.1007/s11606-007-0126-3