Optimizing Hypertension Care for People Living with HIV in Mozambique: Effectiveness, Mechanisms, and Determinants of a Systems Engineering Strategy

Abstract

Hypertension is an increasingly prevalent comorbidity among people living with HIV (PLHIV) in sub-Saharan Africa, yet the majority remain undiagnosed and untreated. Integrating hypertension care into established HIV platforms offers a pragmatic path forward, but achieving sustained improvements in care quality requires strategies that go beyond training and equipment provision to address the systems-level barriers that undermine routine care delivery. This dissertation examines the Systems Analysis and Improvement Approach for Hypertension (SAIA-HTN), a systems engineering strategy that enables frontline clinic teams to use systems engineering tools, namely cascade analysis, process mapping, and iterative quality improvement cycles to identify bottlenecks and optimize integrated care. Using a hybrid type III cluster randomized trial conducted across 16 public-sector outpatient clinics where HIV services were offered, in Sofala and Manica provinces, Mozambique, this research addresses three questions: whether SAIA-HTN improved hypertension outcomes for PLHIV, how it mechanistically produced improvement, and under what organizational and contextual conditions it was successfully adopted, implemented, and sustained. Findings demonstrate that SAIA-HTN led to a more than twofold increase in controlled hypertension compared to control clinics, a significant and sustained effect observed across 65,151 clients. Qualitative analysis of 318 prospectively documented quality improvement cycles revealed four mechanisms of action: shared sensemaking through data visibility, conversion of discretionary practices into system defaults, accountability through iterative feedback loops, and escalation from facility-level fixes to policy-level change. Implementation was shaped by phase-specific determinants, with adoption driven by perceived value and workflow fit and sustained execution depended on leadership engagement and collective efficacy, while long-term sustainability was constrained by data infrastructure and supply chain limitations. Together, these findings advance understanding of how systems-level implementation strategies produce sustained improvements in integrated chronic disease care and provide actionable evidence for scaling SAIA-HTN and similar approaches across sub-Saharan Africa.