RECRUITMENT EXPERIENCE IN THE AFRICAN-AMERICAN STUDY OF KIDNEY-DISEASE AND HYPERTENSION (AASK) PILOT-STUDY

Several approaches for recruitment of African American adults with ren al insufficiency due to hypertension (glomerular filtration rate betwe en 25 and 70 ml/min/1.73 m(2)) were explored in the Pilot Study for th e African American Study of Kidney Disease and Hypertension (AASK). Ov er a period of 42 weeks, prescreening information was obtained on 2880 individuals, of whom 498 (17%) were evaluated at a screening visit. T wo hundred and twenty-five (8%) had an I-125-iothalamate assessment of glomerular filtration rate. Ninety-four of 97 participants who met al l the study eligibility criteria were enrolled in the trial. The most common reasons for ineligibility during screening were absence of rena l insufficiency or hypertension, presence of diabetes mellitus, and a body mass index above the acceptable level. Overall, an average of 31 prescreen contacts and 8 screening visits were conducted for every ran domization (3.3% yield from prescreening to randomization). Screening in clinical practice was the most efficient method for recruitment (12 .6% yield from prescreen contact to randomization compared to 1.1% fro m mass mailing campaigns, 1.3% from mass media campaigns, and 1.7% fro m referrals by patients with end-stage renal disease). Randomization y ields increased with progressively higher age ranges (2.4%, 3.3%, and 6.0% prescreen to randomization yields for those aged less than or equ al to 50, 51-60, and 61-70, respectively). A slight majority (51%) of the prescreen contacts were women, but 75% of the randomized participa nts were men. Our results suggest that clinic-based screening is an ef fective approach for recruitment of African Americans with hypertensio n and renal insufficiency into clinical trials. They also suggest that enrollment of African American women in such studies is a special cha llenge.