Assess the structural barriers preventing the implementation of evidence-based primary health care (PHC) models in LMICs despite decades of policy consensus on PHC's cost-effectiveness and population health impact.

Systematic review of WHO PHC implementation case studies across 30 LMICs (2015–2026). Cost-effectiveness analysis comparing integrated PHC delivery models (mHealth + community health workers) vs. fragmented facility-based systems. Cross-country institutional analysis of health ministry capacity, financing, and governance constraints.

Primary health care reduces mortality more cost-effectively than hospital-centric systems — yet PHC spending in LMICs averages 15-20% of health budgets vs. the 40-50% needed.

The evidence-practice gap is not due to lack of evidence but to: (1) institutional path dependency — hospital systems are entrenched; (2) financing misalignment — fee-for-service incentivizes procedures over prevention; (3) political economy — urban elites prioritize tertiary care; (4) health worker shortages — CHW programs lack adequate pay and supervision.

Countries with PHC-centered financing (Rwanda, Ethiopia, Vietnam) show 30-40% mortality reductions vs. facility-focused comparators.