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BACKGROUND/RATIONALE:
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. Though the effectiveness of hypertension control (Systolic BP [SBP] < 140 mm Hg and diastolic BP [DBP] <90 mm Hg) 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. This proposal is a direct consequence of a HSR&D career development project targeted at optimizing hypertension control in veterans and builds on previous research that demonstrates the feasibility of this approach.
We are conducting a randomized controlled trial (RCT) at 2 VA Medical Centers to evaluate the comparative effect of a tailored stage-matched intervention or a non-tailored intervention to improve hypertension control in veterans with uncontrolled BP. The study addresses important VA priority areas while targeting a chronic condition of enormous importance, hypertension.
OBJECTIVE(S):
The specific aims of the study are:
1) To determine whether a stage-matched intervention (SMi) will lower BP at 6 months compared to usual care (UC) or a health education intervention (HE1) in veterans with uncontrolled hypertension
2) To evaluate whether the SMI 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 or HEI
3) To assess whether veterans randomized to the SMI 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 or HEI.
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
METHODS:
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.
FINDINGS/RESULTS:
This study is actively recruiting. As of the last formal recruitment/retention evaluation (11/19/08), we had enrolled 626 patients of whom 458 completed the run-in period and the baseline visit, 25 were in the run-in period and 143 cancelled their study participation prior to the baseline visit. From these 458 participants, 11 cancelled after their baseline visit leaving 447 that were randomized. Thus, in total, we have 472 active participants (447 randomized and 25 in the run-in period).
There are no planned interim analyses and so we do not have findings about the primary outcomes to report. However, we have submitted abstracts about the methods being used in the study such as: a) Usefulness of the run-in period to reduce dropouts, b) The challenges and promise of blinding in a behavioral trial, c) Importance of measuring BP by automated means to avoid bias, d) Correlations between behavioral constructs and adherence at baseline. We have also published one paper regarding the usefulness of the run-in period in a randomized trial of a behavioral intervention.
IMPACT:
This project builds on previous VA research to test the effect of behavioral interventions in lowering BP 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.
PUBLICATIONS:
None at this time.
DRA:
Chronic Diseases, Health Services and Systems
DRE:
Treatment, Resource Use and Cost, Quality of Care
Keywords:
Behavior (patient), Adherence, Hypertension
MeSH Terms:
none
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