PubMed1987
The Hypertension Detection and Follow-up Program (HDFP), through a two-stage population-based screen for high blood pressure involving over 159,000 persons in 14 U.S. communities, recruited and randomized 11,386 participants. The design initially called for the recruitment of 800-1000 hypertensive individuals per clinic over a 9-month period. The size of the population to be screened was based on an estimated 15% of the general population being age and blood pressure (BP) eligible. All adults 30-69 years of age in defined populations were to be screened, with efforts to enroll into the trial all who met the BP eligibility criteria. Recruitment was carried out by interviewers who enumerated households and screened age-eligible individuals for elevated BP; those meeting BP criteria were invited to a clinic screen for confirmation. Of those persons enumerated, 179,239 were age eligible, and 159,566 of these had home BP measurements. The home screening yielded 22,994 persons who had a diastolic BP at or above 95 mm Hg, and 17,499 attended the clinic screen. At the clinic screen, 11,386 had diastolic BP at or above 90 mm Hg and were randomized into one of two treatment groups. The enumeration goal, and the recruitment yield and cost varied by clinic, primarily due to different characteristics of the defined populations. Overall, the target population approximated U.S. demographic characteristics except that a larger proportion of blacks was included. Because of generally good response rates, the randomized study population was representative of similarly aged hypertensive persons in the target populations. The recruitment results suggest that a population-based screening program for a high prevalence condition such as hypertension is an effective mode of recruitment, particularly when a population-based sample is required.