Interventions to Improve Hypertension Control and Reduce Cardiovascular Disease Risk

BACKGROUND:

Hypertension affects 25% of adults in the United States and remains a leading cause of heart
disease, stroke, and kidney failure. Despite numerous effective treatments, only 25% of
people with hypertension are at goal blood pressure (BP). The chronic care model suggests
that BP control can be achieved by improving patient self-care and the systems through which
care is delivered. Patient self-care efforts should be directed at counteracting the effects
of obesity, physical inactivity, poor dietary pattern, and non-adherence to prescribed
medications on BP. In addition, efforts should be directed at the use of quality improvement
systems that can counteract the well-documented non-adherence of primary care MDs to
established clinical practice guidelines. In addition to improving BP control, these
approaches can also reduce costs associated with hypertension and its consequences. However,
given the resources that would be required to implement such approaches, it is critical that
their effectiveness be rigorously established. This controlled study will test the separate
and combined effects of a behavioral intervention for patients and a CQI intervention for
MDs on BP control. The patient intervention will employ proven behavioral methods for
promoting a healthy lifestyle and adherence to medication regimens. The MD intervention will
use a CQI approach to provide training, motivation, and feedback on performance in a
non-threatening way to promote continuous self-improvement and adherence to clinical
practice guidelines.

DESIGN NARRATIVE:

The Hypertension Improvement Project (HIP) is a randomized, controlled study that will test
the separate and combined effects of a CQI intervention for MDs and a behavioral
intervention for patients on BP control. MDs will be selected from practices in the Duke
Primary Care Research Consortium that serve low-income and minority populations. Practices
will be randomly assigned to the MD intervention or to the MD control condition. Within
these practices, all MDs will receive the same intervention and their patients will be
individually randomized to the patient intervention or to the patient usual care condition.
The MD intervention consists of the following three main elements: 1) on-line training
modules; 2) an evaluation and treatment algorithm for use in the clinic; and 3) a CQI
procedure involving assessment of clinical performance measures and feedback to MDs on their
adherence to guidelines. The performance data will be collected for 18 months and feedback
will be provided to MDs every 3 months. Patients from these practices (approximately 50%
women, at least 40% African American, and 90% low-income) will be randomly assigned to
patient intervention or usual care. The patient intervention consists of a 6-month
behavioral intervention aimed at lifestyle changes to lower BP and promote adherence to
prescribed BP medications. BP and other follow-up measurements will be performed at the end
of the intervention and a year later (at 6 and 18 months post-randomization). The primary
outcome will be the proportion of patients in each treatment group that have adequate BP
control at 6 months. BP control is defined by the Joint National Committee 6 (JNC-6) goals
(systolic BP less than 140 mm Hg and diastolic BP less than 90 mm Hg for most patients;
lower goals for patients with cardiovascular or renal disease, or diabetes). Other outcomes
of this study will include BP control at 18 months, MD adherence to national guidelines, and
patient adherence to lifestyle recommendations and medication regimens. A cost analysis will
also be done. The study will enroll 500 patients in 10 practices (approximately 20 MDs), and
will have 80% power to detect an effect size of 0.3 for the primary outcome. The HIP study
will test practical interventions for improving hypertension control that can be broadly
implemented and can reduce CVD risk.

Inclusion Criteria:

- Receiving primary care from participating physicians from practices in the Duke
Primary Care Research Consortium

- Hypertension

Exclusion Criteria:

- Primary care doctor advises against enrollment

- Pregnant, nursing, or planning pregnancy

- Recent CVD event

- Chronic kidney or liver disease

- Active cancer