Two Self-management Interventions to Improve Hypertension Control
Hayden B. Bosworth, Maren K. Olsen, Janet M. Grubber, Alice Neary, Melinda Orr, Benjamin Powers, Martha Adams, Laura P. Svetkey, Shelby D. Reed, Yanhong Li, Rowena J Dolor, Eugene Ž. Oddone
Abstract
BACKGROUND: Less than 40% of Americans with hypertension have adequate blood pressure (BP) control. OBJECTIVES: To compare two self-management interventions for improving BP control among hypertensive patients. DESIGN: A 2 by 2 randomized trial stratified by enrollment site and patient literacy status with two-year follow-up (5/2004-1/2008). SETTING: Two university-affiliated primary care clinics. PATIENTS: 636 patients were randomized (31% recruitment rate) among the 2060 eligible hypertensive patients. INTERVENTIONS: Research assistants randomized eligible patients via a centralized blinded and stratified randomization algorithm to receive either: 1) usual care; 2) bi-monthly tailored nurse-administered telephone intervention targeting hypertension-related behaviors; 3) BP monitoring consisting of measuring BP three times per week, or; 4) a combination of the two interventions. MEASUREMENTS: The primary outcome was BP control evaluated at six-month intervals over 24 months. 475 (75%) completed the 24-month BP follow-up. RESULTS: Improvements in proportion of BP control for the intervention groups relative to the usual care group at 24 months were: behavioral group, 4.3% (95% CI: −4.5%, 12.9); home BP monitoring group, 7.6% (95% CI: −1.9%, 17.0%); and, combined interventions, 11.0% (95% CI: 1.9%, 19.8%). For systolic BP, relative to usual care, the 24 month difference was, +0.6 mmHg (95% CI: −2.2, 3.4) for the behavioral intervention group, −0.6 mmHg (95% CI: −3.6, 2.3) for the home monitoring group, and −3.9 mmHg (95% CI: −6.9, −0.9) for the combined interventions. Similar patterns were observed for diastolic BP at 24 months. LIMITATIONS: Changes in medication use and diet were only monitored in intervention participants; 25% lacked 24 month outcome data; 73% had adequate BP control at baseline; the study setting was an academic health center, all factors that potentially limit generalizability. CONCLUSION: Combined home BP monitoring and tailored behavioral telephone intervention improved BP control, systolic BP, and diastolic BP at 24 months relative to usual care.