Trial of Low and High Intensity Strategies to Maintain BP Control

Trial of Low And High Intensity Strategies to Maintain Blood Pressure Control

The long-range goal of this research is to advance understanding of long-term blood pressure (BP) control in patients with uncontrolled hypertension (HTN). The work builds on our experience in implementing new models of care in Veterans Affairs (VA) and non-VA settings, including three National Institute of Health (NIH) studies of pharmacist-based HTN management. The long-term effectiveness of such models, especially in veterans, is unknown. Thus, the primary goal of this study is to evaluate how to sustain long-term BP control in veterans with HTN following a 6-month intensive pharmacist intervention.

This study will enroll veterans with uncontrolled HTN into a 6-month intensive pharmacist-based intervention. Following this initial intervention, participants will be randomized to continued intervention or a one-time patient and provider education intervention. BP will be compared in the two groups over a 2-year follow-up period. The intervention to control and sustain BP will follow VA guidelines and include: 1) comprehensive medication assessment by the pharmacist; 2) an explicit plan to intensify treatment if indicated; 3) strategies to improve adherence; and 4) follow-up pharmacist visits to sustain BP control. The intervention is based on models identified in a recent Agency for Healthcare Research and Quality (AHRQ) report as being the most potent strategies to improve BP. The study will benefit from a strong research team with expertise in guideline development, implementation science, quality measurement, and behavioral science. The study will also provide important information on the degree to which BP control deteriorates after patients are referred back to usual care. The specific aims and related hypotheses of the study are to:

Aim 1:Compare BP control in patients randomized to long-term continuation of the pharmacist intervention or to a less intense one-time patient and provider education intervention.

Hypothesis 1a: Patients randomized to the continued pharmacist intervention will have higher rates of BP control 24 months after randomization.

Hypothesis 1b: Patients randomized to the continued pharmacist intervention will have lower mean BP 24 months after randomization.

Aim 2: Compare antihypertensive medication intensification in patients randomized to the continued pharmacist intervention or the less intense intervention.

Hypothesis 2: A higher proportion of patients who continued the pharmacist intervention will have medication intensification over the 24-month follow-up.

Aim 3: Compare medication adherence in the two intervention groups. Hypothesis 3a: Medication adherence will be higher in patients randomized to the continued pharmacist intervention group during the 24 month follow-up period.

Hypothesis 3b: Improvements in medication adherence will be associated with improvements in BP during each study interval.

We are proposing a 4-year trial to determine if long-term blood pressure (BP) control after a pharmacist intervention requires continuation of the intervention or if a less intense strategy is equally efficacious. The intervention builds on the Chronic Care Model, recent Veteran Affairs (VA) trials, and our pharmacist interventions. This research has convincingly shown that collaborative interventions can improve BP control over 6-9 months. However, no randomized study has evaluated strategies to sustain the effect of such interventions.

The study will enroll 300 patients with uncontrolled HTN at the Iowa City Veteran Affairs Medical Center (VAMC) and an affiliated community based outpatient clinic (CBOC). All patients will receive a pharmacist intervention for 6 months that will follow VA HTN guidelines. Patients completing the intervention will then be randomized to continuation of the high intensity intervention or to a one-time patient and provider education intervention that was recently shown to be effective. The high intensity (HI) intervention will intensify medication regimens when BP deteriorates, sustain adherence, and improve monitoring to reduce adverse drug reactions. The low intensity (LI) intervention will involve usual care by patients primary care provider (PCPs) and a one-time education intervention including a letter emphasizing the importance of medication adherence and behavioral strategies to improve BP control (e.g., low-salt diets, exercise). PCPs of low intensity patients will also receive a computerized alert with treatment recommendations and links to BP guidelines.

The primary endpoint-BP-will be assessed using standard measurements at 6, 12, 18, 24, and 30 months post enrollment (24 months after randomization). The 24-month evaluation phase will determine if BP control can be sustained or improved with a continued high intensity intervention, relative to a low intensity intervention (Aim 1). All medication changes will be assessed to compare rates of medication intensification over the follow-up period (Aim 2). Finally, validated self-report adherence questionnaires will be used to compare medication adherence in the two groups and determine relationships between BP control and medication adherence (Aim 3).

Inclusion Criteria:

• Diagnosis of Hypertension (HTN) captured by ICD-9-CM codes from prior outpatient visits;
• elevated BP (>140/90 mmHg among non-diabetics; or >140/80 mmHg among diabetics) during the most recent VA clinic visit or based on the average from the last 3 visits;
• elevated BP measured by the Research Medical Assistant (MA) at the baseline visit.

Exclusion Criteria:

Patients will be excluded for the following safety reasons:

• prior history or current signs of hypertensive emergency including symptoms of angina, stroke, or acute renal failure;
• severe HTN (systolic BP >200 or diastolic BP > 114mm Hg);
• history of acute MI, stroke, or unstable angina in the prior 6 months;
• Congestive Heart Failure (CHF) due to systolic dysfunction with a left ventricular ejection fraction < 35% documented by echocardiography, nuclear medicine study, or ventriculography;
• renal insufficiency, defined by a glomerular filtration rate less than 30 ml/min or previously documented proteinuria > 1 gram per day;
• significant hepatic disease, including prior diagnoses of cirrhosis, Hepatitis B or C infection, or laboratory abnormalities (serum ALT or AST > 2 times control or total bilirubin > 1.5 mg/dl) in the prior 6 months;
• pregnancy;
• prior diagnoses of pulmonary hypertension or sleep apnea (unless treated by continuous positive pressure ventilation);
• poor prognosis with a life expectancy estimated less than 2 years;
• residence in a nursing home or diagnosis of dementia;
• inability to give informed consent or impaired cognitive function (defined as > 3 errors on the 10-item Pfeiffer Portable Mental Status Questionnaire, administered during study intake);
• no telephone for follow-up calls.