Two self-management interventions to improve hypertension control: a randomized trial

Abstract

Background: Fewer than 40% of persons with hypertension in the United States have adequate blood pressure (BP) control.

Objective: To compare 2 self-management interventions for improving BP control among hypertensive patients.

Design: A 2 x 2 randomized trial, stratified by enrollment site and patient health literacy status, with 2-year follow-up. (ClinicalTrials.gov registration number: NCT00123058).

Setting: 2 university-affiliated primary care clinics.

Patients: 636 hypertensive patients.

Intervention: A centralized, blinded, and stratified randomization algorithm was used to randomly assign eligible patients to receive usual care, a behavioral intervention (bimonthly tailored, nurse-administered telephone intervention targeting hypertension-related behaviors), home BP monitoring 3 times weekly, or the behavioral intervention plus home BP monitoring.

Measurements: The primary outcome was BP control at 6-month intervals over 24 months.

Results: 475 patients (75%) completed the 24-month BP follow-up. At 24 months, improvements in the proportion of patients with BP control relative to the usual care group were 4.3% (95% CI, -4.5% to 12.9%) in the behavioral intervention group, 7.6% (CI, -1.9% to 17.0%) in the home BP monitoring group, and 11.0% (CI, 1.9%, 19.8%) in the combined intervention group. Relative to usual care, the 24-month difference in systolic BP was 0.6 mm Hg (CI, -2.2 to 3.4 mm Hg) for the behavioral intervention group, -0.6 mm Hg (CI, -3.6 to 2.3 mm Hg) for the BP monitoring group, and -3.9 mm Hg (CI, -6.9 to -0.9 mm Hg) for the combined intervention group; patterns were similar for diastolic BP.

Limitation: Changes in medication use and diet were monitored only in intervention participants; 24-month outcome data were missing for 25% of participants, BP control was adequate at baseline in 73% of participants, and the study setting was an academic health center.

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. .

Figure 1

TCYB Recruitment Flowchart ^a No longer receiving care at Duke clinics, receiving dialysis, received organ transplant, residing in nursing home or receiving home health care, no phone, or had pulmonary hypertension

Figure 2

Estimated ^a Proportion in Blood Pressure Control (95% CI), by Intervention Group ^a Estimates are marginalized probabilities from a logistic mixed effects regression model. (22) The model-estimated intra-patient correlation was 0.48. 95% confidence intervals at 12 and 24 months were derived from 1000 bootstrap samples.

Figure 3

Estimated ^a Mean Systolic Blood Pressure (95% CI), by Intervention Group ^a Estimates are based on a general linear model with an unstructured covariance matrix. The model-estimated systolic blood pressure correlation between time points ranged from 0.41 (baseline and 24 months) to 0.57 (months 6 and 12).

Figure 4

Estimated ^a Mean Diastolic Blood Pressure (95% CI), by Intervention Group ^a Estimates are based on a general linear model with an unstructured covariance matrix. The model-estimated diastolic blood pressure correlation between time points ranged from 0.54 (baseline and 24 months) to 0.66 (baseline and 6 months).