High blood pressure (BP) is the most common chronic condition among veterans (prevalence 37%). It affects more than 1 million veterans, and greatly increases their risk for cardiovascular disease (CVD) and kidney failure. Diet, exercise and medications are primary therapy with the target BP being < 140/90 mm Hg in most adults [<130/80 mm Hg in diabetes and chronic kidney disease]. Though the effectiveness of hypertension control (< 140/90 mm Hg in most adults [<130/80 mm Hg in diabetes and chronic kidney disease) in preventing CVD is well established, a significant gap exists between ideal control rates and what is actually achieved. Insufficient treatment adherence contributes to poor BP control, and clinicians are faced with the difficult challenge of motivating their patients to exercise, diet, and take drugs as prescribed. Despite the relative ease and low cost of treating high BP, and despite being prescribed treatment, many patients remain nonadherent and have uncontrolled hypertension.
We conducted a randomized controlled trial (RCT) at 2 VA Medical Centers to evaluate the comparative effectiveness of a tailored stage-matched intervention or a non-tailored health education intervention to improve hypertension control in veterans with uncontrolled BP. Usual care served as the control group. The study addresses important VA priority areas while targeting a chronic condition of enormous importance, hypertension.
The specific aims of the study were:
1) To determine whether a stage-matched intervention (SMi) or a health education intervention (HE1) will lower BP at 6 months compared to usual care (UC) in veterans with uncontrolled hypertension
2) To evaluate whether the SMI or HEI is effective in improving adherence to exercise, diet, or medications at 6 months in participants who receive the SMI compared to participants who receive UC
3) To assess whether veterans randomized to the SMI or HEI achieve sustained benefit to significantly lower BP and improve adherence 6 months after intervention completion (i.e., 12 months after randomization) compared to those on UC.
4) To examine the effect of SMI on patient's health-related quality of life, satisfaction, and acceptability.
5) To determine the cost-effectiveness of the SMI
Veterans with uncontrolled hypertension are randomized equally to 3 groups: 1) The Stage-Matched Intervention (SMI) uses the Transtheoretical model (TTM) as the overall study framework (constructs: stages of change, decisional balance, and self-efficacy), while also incorporating key aspects of Bandura's social cognitive theory, behavioral self-management and the skills model of adherence. Veterans in this group receive TTM stage-matched counseling for exercise, diet, and medications based on current stage. A counselor assesses each participant's current stage for each behavior and uses a previously developed and tested computerized system to deliver the appropriate standardized SMI. The SMI is based on the processes of change tailored to each veterans responses to the stage of change, decisional balance and self-efficacy. 2) The Health Education Intervention (HEI) group receives monthly education about hypertension management, and 3) The Usual Care (UC) group receives care as usual.
The randomized participants are followed for a total of 12 months. There is an initial 6-month active intervention phase following which the intervention is stopped and patients followed for another 6 months to assess sustainability of the intervention.
Participants make in-person visits to the VAMC's at baseline and at 3, 6, and 12 months. BP, the primary outcome, is measured from several BP readings (at least 5 mm apart), and analyzed as categorical (<140/90 or not) or continuous. Secondary outcomes include adherence to diet, exercise and medications; quality of life; satisfaction; acceptability; cost and cost-effectiveness. In order to preserve the benefits of randomization and guard against bias, the study will be analyzed using longitudinal data analysis methods using an "intention to treat" strategy.
There were no differences between groups at baseline. Baseline BP control was 42.6%, 40.6%, and 44.6% in SMI, HEI, and UC (p = .74); the corresponding SBP (with standard errors [SE]) was 136 (0.89), 137 (1.33) and 137 (0.96) mm Hg, respectively. The 6-month BP control was 64.6% (SMI), 54.3% (HEI), and 45.8% (UC) [p values for pairwise comparisons: .001 (SMI vs. UC) and .108 (HEI vs. UC). At 6-month follow-up, the SBP (SE) was 131.2 (1.05), 131.8 (.99) and 134.7 (1.02) for SMI, HEI, and UC respectively [p values: SMI vs. UC 0.009; HEI vs. UC, 0.047]. At 12 months SMI (62%) had better BP control than UC (52%) [p=.03]. There were no differences in QOL between the arms. HEI had greater satisfaction and acceptability than SMI.
SMI led to lower SBP and better BP control compared to UC. Importantly, the trial did not involve in-person contact, which increases scalability and reduces intervention costs. This SMI may be a valuable tool for targeting and improving BP control rates among Veterans with sustained uncontrolled hypertension.
This project builds on previous VA research to test the effect of behavioral interventions in lowering BP and acheiving better hypertension control by improving adherence to antihypertensive therapy (medication, exercise, and diet). It may provide the scientific rationale, not only for using such interventions to improve BP control, but also for other conditions where sustained adherence is a problem. This could be an efficient and cost-effective way to enhance treatment adherence and improve outcomes- among veterans living at a distance. This research may also influence future health behavior studies in veterans to achieve better clinical outcomes.
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