The design and rationale of a multicenter real-world trial: The Southeastern Collaboration to Improve Blood Pressure Control in the US Black Belt - Addressing the Triple Threat

Background: Impoverished African Americans (AA) with hypertension face poor health outcomes.

Purpose: To conduct a cluster-randomized trial testing two interventions, alone and in combination, to improve blood pressure (BP) control in AA with persistently uncontrolled hypertension.

Methods: We engaged primary care practices serving rural Alabama and North Carolina residents, and in each practice we recruited approximately 25 AA adults with persistently uncontrolled hypertension (mean systolic BP >140 mmHg over the year prior to enrollment plus enrollment day BP assessed by research assistants ≥140/90 mmHg). Practices were randomized to peer coaching (PC), practice facilitation (PF), both PC and PF (PC + PF), or enhanced usual care (EUC). Coaches met with participants from PC and PC + PF practices weekly for 8 weeks then monthly over one year, discussing lifestyle changes, medication adherence, home monitoring, and communication with the healthcare team. Facilitators met with PF and PC + PF practices monthly to implement ≥1 quality improvement intervention in each of four domains. Data were collected at 0, 6, and 12 months.

Results: We recruited 69 practices and 1596 participants; 18 practices (408 participants) were randomized to EUC, 16 (384 participants) to PF, 19 (424 participants) to PC, and 16 (380 participants) to PC + PF. Participants had mean age 57 years, 61% were women, and 56% reported annual income <$20,000.

Limitations: The PF intervention acts at the practice level, possibly missing intervention effects in trial participants. Neither PC nor PF currently has established clinical reimbursement mechanisms.

Conclusions: This trial will fill evidence gaps regarding practice-level vs. patient-level interventions for rural impoverished AA with uncontrolled hypertension.