Using direct mail to recruit hispanic adults into a dietary intervention: An experimental study

Identifying strategies for successful recruitment of ethnic minorities into scientific studies is critical. Without effective methods, investigators m ay fail to recruit the desired sample size, take longer to recruit than pla nned, and delay progress for research in minority health. Direct mail is ar t appealing recruitment method because of the potential for reaching large target populations and producing a high volume of inquiries about a study w ith relatively little staff effort. To determine which of three direct mail strategies yielded higher recruitment, 561 Hispanic employees were randoml y assigned to receive either (a) a flyer about a worksite dietary intervent ion; (b) the same flyer plus a personalized hand-signed letter containing h eart disease risk statistics for the general American population; or (c) th e flyer plus a personalized hand-signed letter containing statistics for Hi spanics. Two orthogonal chi-square comparisons were examined. The personali zed letters plus flyer yielded a significantly higher response rate (7.8%) than the flyer alone (2.1%), X-2(1, N = 561) = 7.5, p = .006. However the p ersonalized letter with Hispanic heart disease risk statistics did not yiel d a statistically significant higher response rate (9.1%) than the letter w ith the general population risk statistics (6.5%), X-2(1, N = 370) = 0.9, p >.34. These findings suggest that personalized approaches can increase the effectiveness of direct mail efforts for recruiting ethnic minorities into interventions and may be particularly helpful for large-scale intervention s.