Effectiveness of Implementing an Intensive Blood Pressure Reduction Intervention on Cognitive Decline in Low-income and Minority Hypertensive Patients
Project Summary/Abstract African American and low-income populations bear a disproportionate burden of dementia and have been underrepresented in trials of cognitive impairment. The Systolic Blood Pressure Intervention Trial (SPRINT) showed that an intensive blood pressure (BP) intervention (target systolic BP <120 mmHg) lowered the risk of cognitive impairment compared to a standard BP intervention (systolic BP target <140 mmHg). The next important step is to determine how the successful SPRINT intensive blood pressure intervention can be implemented in a real-world clinic setting to prevent cognitive decline. The overall objective of the proposed study is to test a multifaceted strategy for implementing an intensive BP intervention protocol adapted from SPRINT targeting systolic BP <120 mmHg on cognitive decline in racial minority and low-income hypertensive patients in resource-constrained primary care practices in Louisiana and Mississippi. The RE-AIM (Reach Effectiveness Adoption Implementation Maintenance) framework has been used to guide the development and evaluation of the multifaceted implementation strategy, including protocol-based treatment that employs the SPRINT stepped-care intensive BP management algorithm, dissemination of SPRINT findings, shared- decision making, team-based collaborative care, BP audit and feedback, home BP monitoring, and patient health coaching. Building on the ongoing Implementation of Multifaceted Patient-Centered Treatment Strategies for Intensive Blood Pressure Control (IMPACTS) trial, we will cost-effectively conduct a cluster- randomized trial in 36 Federally Qualified Health Center clinics that serve low-income populations in Louisiana and Mississippi. The primary outcome in the proposed trial is the net difference in mean change of global cognitive composite z-score from baseline to 42 months between the intervention and enhanced usual care groups. Secondary outcomes include net difference in mean change of executive function and memory composite z-scores, systolic and diastolic BP, adverse effects, and quality of life. Implementation outcomes, including acceptability, adaptation, adoption, feasibility, fidelity, penetrance, cost-effectiveness and sustainability, will also be collected and used to improve intervention delivery during the trial. The proposed trial, with a sample size of 36 clinics (35 patients/clinic), has 85% statistical power to detect a 0.30 or higher difference in the global cognitive composite z-score at a 2-sided significance level of 0.05 assuming 20% loss to follow-up and an intra-cluster correlation of 0.05. In a meta-analysis of 5 clinical trials, the pooled effect size was 0.35 (95% CI 0.32, 0.38) for the global cognitive composite z-score. This study will generate urgently needed data on effective, adoptable, and equitable intervention strategies to reduce blood pressure-related cognitive decline in low-income and minority populations. If proven effective, the implementation strategy for intensive blood pressure reduction could be adapted and scaled up in diverse primary care settings to prevent cognitive decline and clinical dementia.