Caribbean and South American team-based strategy to control hypertension (CATCH): Rationale and study design of a cluster randomized trial

RATIONALE: Hypertension disproportionately affects populations in low- and middle-income countries (LMICs), especially in Latin America and the Caribbean, due to its high prevalence and low control rate. PRIMARY HYPOTHESIS: To close the knowledge-practice gap for blood pressure (BP) control, we are assessing the effectiveness and implementation of a team-based care strategy for BP control in primary care clinics in Colombia and Jamaica. DESIGN: The Caribbean and South American Team-based Strategy to Control Hypertension (CATCH) study is a cluster randomized trial using an effectiveness-implementation hybrid type-2 design. Clinics were randomly assigned to a team-based strategy or a provider-training strategy to implement current hypertension guidelines. The team-based strategy includes healthcare team training, care coordination, task sharing, BP audit and feedback, home BP monitoring, health coaching, single-pill combination therapy, and increased medication access. The primary clinical effectiveness outcome is difference in mean change of systolic BP from baseline to 18 months between randomized groups. The primary implementation outcome is a composite fidelity score to key implementation strategy components. SITES: CATCH is conducted in 40 primary care clinics in Jamaica and Colombia. ENROLLMENT: Between February 2023 and August 2024, we recruited 1,707 participants, exceeding our planned enrollment. The planned sample size of 1,680 (42 patients per each of 40 clinics) has 90% statistical power to detect a 6.0 mm Hg difference in mean systolic BP change assuming 85% follow-up and a 2-sided significance level of 0.05. CURRENT STATUS: In follow-up CONCLUSIONS: CATCH will provide evidence on effectiveness and implementation of a team-based care strategy to improve hypertension control in real-world, primary care settings. If proven effective, this approach can be scaled up in primary care throughout low- and middle-income countries (LMICs). CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, NCT05405920 https://clinicaltrials.gov/study/ NCT05405920.