Analytical Investigation of Patient Flow Optimization in Accident and Emergency Departments in Tertiary Hospitals, North West Nigeria

Accident and emergency (AE) departments in Nigerian tertiary hospitals are chronically congested, with prolonged waiting times contributing to adverse patient outcomes and departures before clinical assessment. This study applies queuing analysis, process simulation, and lean process improvement principles to optimize patient flow in AE departments of three tertiary hospitals in Kano and Sokoto States, North West Nigeria. Patient flow data including arrival timestamps, triage classifications, time-to-physician contact, investigation turnaround times, admission decisions, and departure times are extracted from the hospitals' electronic health records and supplemented by direct observation over a 10-week period. Simulation models are built in Arena simulation software, validated against observed performance metrics, and used to experiment with alternative process configurations. Four improvement scenarios are tested: additional triage nurses, a fast-track stream for low-acuity patients, point-of-care diagnostic equipment, and a senior physician in triage. Results indicate that a combined fast-track stream and senior physician in triage scenario reduces average AE length of stay by 38 percent and the proportion of patients waiting more than four hours by 61 percent. The fast-track stream alone offers the greatest cost-effectiveness ratio among single interventions. Process mapping reveals that investigation result turnaround constitutes the longest avoidable delay component across all three hospitals. Recommendations include implementing fast-track streams, investing in point-of-care testing, and establishing monthly AE flow performance reviews. Keywords: patient flow, accident and emergency, simulation, North West Nigeria, process optimization