Recruiting under-represented populations into psychiatric research: Results from the help for hoarding study

This study compares the effectiveness of approaches used to recruit a diverse sample for a randomized clinical trial for Hoarding Disorder (HD) in the San Francisco Bay Area. Of the 632 individuals who inquired about the study, 313 were randomized and 231 completed treatment. Most participants heard about the study via flyering (N = 161), followed by advocacy groups (N = 113), word of mouth (N = 84), health care professionals (N = 78), online (N = 68), and media (N = 11). However, those that heard about the study via advertising methods, such as flyers, were less likely to complete the study, p = .01, while those recruited via advocacy groups were most likely to be randomized, p = .03. No source proved more effective in recruiting underrepresented groups such as men, p = .60; non-whites, p = .49; or Hispanics, p = .97. Advertising recruited the youngest individuals, p < 0.001, and word of mouth was most likely to recruit unemployed, disabled, or retired individuals, p = .01. Thus, results suggest an ongoing multimodal approach is likely to be most effective in both soliciting and retaining a diverse sample. Future studies should compare recruitment methods across greater geographical regions too, as well as in terms of financial and human costs.