title: Recruitment for phase II of the Trials of Hypertension Prevention. Effective strategies and predictors of randomization. Trials of Hypertension Prevention (TOHP) Collaborative Research Group.
abstract: Phase II of the Trials of Hypertension Prevention is a multicenter, randomized, controlled trial designed to determine the efficacy of weight loss and reduction of sodium intake for lowering blood pressure and incidence of hypertension among persons with high-normal levels of blood pressure. The 2 x 2 factorial study design includes weight loss alone, restricted sodium intake alone, the combination of weight loss and sodium restriction, and a control group. Nine clinical centers used a variety of recruitment strategies to enroll 2382 participants over 17 months, which exceeded the sample size goal of 2250. Among randomized participants, 21% were minorities and 34% were women. Overall, direct mail generated the most randomized participants (73%), followed by community screening (12%) and media advertisement (11%). Referrals from community health care providers yielded few participants. Prescreening improved overall efficiency and reduced costs. Participants who were more likely to drop out voluntarily during the three-visit screening regimen tended to be younger, single, male, smokers, and less educated.
authors.affiliation: Kaiser Permanente Center for Health Research, Portland, OR 97227-1098, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Hollis
authors.forename: S
authors.initials: S
authors.lastname: Satterfield
authors.forename: F
authors.initials: F
authors.lastname: Smith
authors.forename: M
authors.initials: M
authors.lastname: Fouad
authors.forename: P S
authors.initials: PS
authors.lastname: Allender
authors.forename: N
authors.initials: N
authors.lastname: Borhani
authors.forename: J
authors.initials: J
authors.lastname: Charleston
authors.forename: M
authors.initials: M
authors.lastname: Hirlinger
authors.forename: N
authors.initials: N
authors.lastname: King
authors.forename: R
authors.initials: R
authors.lastname: Schultz
mesh_terms: D000328:Adult; D001794:Blood Pressure; D003131:Combined Modality Therapy; D004039:Diet, Sodium-Restricted; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009922:Oregon / Q000453:epidemiology; D010352:Patient Dropouts; D010358:Patient Participation; D018579:Patient Selection; D012107:Research Design; D015431:Weight Loss