Behavioral Study to Control Blood Pressure

Overview

We propose to test an intervention to increase patients' understanding of the causes, consequences, and the rationale for treatment, of their hypertension (HTN), as a strategy for increasing blood pressure (BP) control. The focus is on the interaction between a behavioral intervention to reduce BP - home BP monitoring (HBPM) - and patient knowledge, which, we propose, moderates the effect of the HBPM intervention. We hypothesize that patients who have a better understanding of their illness and its prescribed treatment will be more adherent to the treatment regimen, and thus will exhibit improved outcomes compared to those who have been exposed to the same intervention, but who do not have a clear understanding of these elements.

According to the National Health and Nutrition Examination Survey, more than 31% of adults in the U.S. population have hypertension (HTN). HTN is a major risk factor for heart disease and stroke, which are the 1st and 3rd leading causes of death in the U.S. and impose an enormous financial and social burden on Americans with more than $352 billion spent in direct and indirect costs. Behavioral interventions to control blood pressure (BP) have exhibited, on average, positive but relatively modest effects on blood pressure control. We and others have studied the effects of one such intervention - home BP monitoring - on BP control in hypertensive patients, and found reliable, albeit modest effects. We have found similar effects for another behavioral intervention, Motivational Interviewing, on BP control. We hypothesize that the effects of such interventions will be augmented when accompanied by a systematic approach to patient education concerning their illness and its treatment. The literature suggests that patient education is "necessary but not sufficient"(an implicit interaction) to produce behavioral changes; however, the "necessary" part tends to be ignored by interventionalists. The implication of the interaction is that when patients lack the necessary knowledge, any intervention is likely to be less effective (as any value multiplied by zero - i.e., no knowledge - is zero). In spite of this, we have found no trials that have tested the interaction between patient knowledge and a lifestyle or drug intervention. We propose to test an intervention to increase patients' understanding of the causes, consequences, and the rationale for treatment, of their HTN, as a strategy for increasing BP control. The focus is on the interaction between a behavioral intervention to reduce BP - home BP monitoring (HBPM) - and patient knowledge, which, we propose, moderates the effect of the HBPM intervention. We hypothesize that patients who have a better understanding of their illness and its prescribed treatment will be more adherent to the treatment regimen, and thus will exhibit improved outcomes compared to those who have been exposed to the same intervention, but who do not have a clear understanding of these elements. We propose to pilot test the effect of the HBPM intervention using a 2 X 2 independent groups randomized design, to allow us to compare the effects of Usual Care (UC) + Printed Materials (PM) compared to Usual Care (UC) and Self-Paced Programmed Instruction (SPPI) compared to Home Blood Pressure Monitoring (HBPM) + Printed Materials (PM) compared to Home Blood Pressure Monitoring (HBPM) + Self-Paced Programmed Instruction (SPPI). Our primary hypothesis is: Decreased ABP at 3 months will be ordered thusly: HBPM+SPPI \> HBPM+PM \> UC+SPPI \> UC+PM