Systems Thinking Analysis of Nigeria’s Essential Medicines Policy: Failures, Feedback Loops, and Recommendations for Systemic Reform Across All Geopolitical Zones

Nigeria's Essential Medicines Policy, intended to ensure the equitable availability of priority medicines across all geopolitical zones, has persistently failed to achieve its objectives despite successive policy revisions, resulting in chronic stockouts, irrational substitution, and inequitable access. Conventional linear policy analyses have failed to explain the persistence of these failures, suggesting that systems thinking approaches may provide more penetrating insights into the feedback dynamics sustaining policy underperformance. This study applied a systems thinking methodology to analyze Nigeria's Essential Medicines Policy, identifying causal feedback loops, systemic archetypes, and leverage points for reform. A participatory group model building approach engaged 84 purposively sampled stakeholders across all six geopolitical zones, including federal and state pharmacy officials, supply chain managers, healthcare workers, patient advocates, pharmaceutical manufacturers, and development partners, in causal loop diagramming and system archetype identification workshops over 18 months. Quantitative system dynamics modelling was subsequently conducted to simulate policy scenario trajectories over a 20-year horizon. Analysis identified 14 reinforcing and 9 balancing feedback loops shaping essential medicine availability dynamics. Three dominant systemic archetypes were identified: shifting the burden, where emergency procurement perpetually displaces investment in systemic supply chain capacity; eroding goals, where procurement targets are repeatedly lowered in response to financing shortfalls; and tragedy of the commons, where decentralized procurement decision-making without coordination produces collective supply chain fragmentation. High-leverage systemic reforms identified include integrated supply chain governance, ring-fenced essential medicine financing, and pharmacist-led quantification institutionalization. Keywords: systems thinking, essential medicines policy, causal loop diagrams, Nigeria, health system reform