The total number of persons prescreened via telephone during an 18-month recruitment period was 2,209 (Figure 1). Of these, 72% (1,596 of 2,209) were ineligible, and 13% (297 of 2,209) declined to participate, leaving 316 persons who were randomized to 1 of the 4 treatment groups. The characteristics of the randomized cohort are shown in Table 1.