The Take Control of Your Blood pressure (TCYB) study: study design and methodology

Among the 65 million Americans with hypertension, only approximately 31% have their blood pressure under control (<140/90 mm/Hg). Despite the damaging impact of hypertension and the availability of evidence-based target values for blood pressure, interventions to improve blood pressure control have had limited success.

A randomized controlled health services intervention trial with a two by two design is being conducted to improve blood pressure control. This five-year trial evaluates two patient-directed interventions designed to improve blood pressure control among patients diagnosed with hypertension in a community-based primary care setting.

Patients are randomized to one of four groups: usual care, home blood pressure monitoring, tailored behavioral self-management intervention that is administered via telephone by a nurse, or a combination of the home blood pressure monitoring and tailored behavioral intervention. Patients receiving the home blood pressure monitoring are trained in the use of an electronic blood pressure measurement device, are asked to measure their blood pressure 3 times/week, and send in two-month blood pressure recordings throughout the 24-month study duration. The behavioral intervention incorporates patients' need assessments and involves tailored behavioral and education modules to promote medication adherence and improve specific health behaviors. A nurse delivers all behavioral self-management modules over the telephone bi-monthly for 24 months. The primary outcome is the proportion of patients who achieve control of their blood pressure based on evidence-based guidelines (for patients without diabetes <140/90 mm/Hg, for patients with diabetes <130/80 mm/Hg) evaluated at six-month intervals over 24 months (five measurements) using a random-zero sphygmomanometer.

Despite the known risk of poor blood pressure control, and the wide availability of effective treatment strategies, a majority of adults still do not have their blood pressure controlled. This study will be an important step in defining two explicit interventions to improve blood pressure control. To our knowledge, this study is the first to combine both a tailored behavioral self-management intervention and self-monitoring home blood pressure intervention to improve blood pressure control among patients in a primary care setting.