A Complex Systems Theory Investigation of Diagnostic Imaging Quality Failure in Nigerian Public Hospitals: Emergent Properties, Feedback Loops, and Policy Implications

Diagnostic imaging quality failure in Nigerian public hospitals is a systemic phenomenon that resists explanation through linear cause-effect models because it emerges from the interactions of multiple interconnected components, including equipment, workforce, supply chains, governance, and patient factors, within an adaptive complex system. This study applies complex systems theory to investigate the emergent properties and feedback loops driving imaging quality failure in Nigerian public hospitals, generating theoretically grounded policy levers. A multimethod complex systems research design is applied across three phases: quantitative system dynamics modelling of the imaging quality system using causal loop diagram construction and stock-flow modelling in Vensim software, informed by stakeholder data collection from 150 radiology department staff across 24 hospitals in six zones; qualitative agent-based modelling simulation exploring how individual radiographer and manager behaviour aggregates to system-level quality outcomes; and policy analysis of simulation experiments testing alternative intervention scenarios. The original theoretical contribution is a Complex Systems Model of Nigerian Diagnostic Imaging Quality Failure, identifying the equipment-maintenance-quality feedback loop as the highest-leverage systemic failure mechanism. Available complex systems health research literature from Nigeria identifies supply chain failure as the critical system input most sensitive to policy intervention. The Complex Adaptive Systems Theory by Plsek and Greenhalgh and the Policy Resistance framework by Sterman provide the theoretical grounding. Findings generate novel evidence-based policy recommendations that account for feedback amplification and system resistance effects. Keywords: complex systems theory, imaging quality failure, Nigerian public hospitals, system dynamics, policy implications.