The veterans' study to improve the control of hypertension (V-STITCH): design and methodology

Among the 60 million Americans with hypertension, only approximately 31% have their blood pressure (BP) under control (<140/90 mm Hg). Despite the damaging impact of hypertension and the availability of evidence-based target values for BP, interventions to improve BP control have had limited success.

A randomized controlled health services intervention trial with a split-plot design is being conducted to improve BP control. This 4-year trial evaluates both a patient and a provider intervention in a primary care setting among diagnosed hypertensive veterans.

In a cluster-randomization, 30 primary care providers in the Durham VAMC Primary Care Clinic were randomly assigned to receive the provider intervention or control. The provider intervention is a patient-specific electronically generated hypertension decision support system (DSS) delivering guideline-based recommendations to the provider at each patient's visit, designed to improve guideline-concordant therapy. For these providers, a sample of their hypertensive patients (n=588) was randomly assigned to receive a telephone-administered patient intervention or usual care. The patient intervention incorporates patients' need assessments and involves tailored behavioral and education modules to promote medication adherence and improve specific health behaviors. All modules are delivered over the telephone bi-monthly for 24 months. In this trial, the primary outcome is the proportion of patients who achieve a BP < or =140/90 mm Hg at each outpatient clinic visit over 24 months.

Despite the known risk of poor BP control, a majority of adults still do not have their BP controlled. This study is an important step in testing the effectiveness of a patient and provider intervention to improve BP control among veterans in the primary care setting.