Recruitment and baseline characteristics of participants in the Dietary Approaches to Stop Hypertension trial

Dietary Approaches to Stop Hypertension (DASH) was a randomized, multicente r feeding study designed to assess the effects of modifying dietary pattern s on blood pressure. Among the most challenging aspects of conducting the D ASH trial nas the recruitment of participants at the 4 clinical centers. As part of the recruitment drive, 347,500 brochures were mailed, 250,500 coup ons were distributed in coupon packs, 114 advertisements were published in newspapers or bulletins, 140 radio and 74 television advertisements were br oadcast, and 68 screening events and presentations were conducted. These ef forts yielded a total of 459 enrolled participants, ahead of schedule. The most common source of participants was mass mailing of individual brochures (n=194, 42.3%), followed by word-of-mouth (n=82, 17.8%), and then other ty pes of mass mailing (n=44, 9.6%). Recruitment of minority participants foll owed a similar pattern. Among the 3,192 persons attending the first in-pers on screening visit, the major reason for nonenrollment was low blood pressu re (56%) rather than a diet-related factor. The study population was demogr aphically heterogeneous (49% women, 60% African American, 48% married, and 77% employed full-time). On average, the diet of participants before the DA SH feeding study was more similar to the trial control diet than to the com bination diet, which reduced blood pressure more effectively. In summary, r ecruitment of a heterogeneous study population that includes a substantial number of minority participants is a feasible undertaking. However, the eff ort is considerable and requires a major commitment of resources.