Development and evaluation of a leanbased model for the Emergency Department of a public university hospital in Malaysia

Abstract

Emergency Department (ED) overcrowding remains a persistent challenge, contributing to prolonged waiting times, rising operational costs, and undermining public confidence in healthcare systems. Although Lean has been widely implemented in ED settings, many evaluations rely on isolated tool applications and simple pre-post comparisons, with limited integration of economic evaluation. Evidence on systematically designed, validated Lean models evaluated using quasi-experimental and cost-efficiency approaches remains limited. This study aimed to design and develop a Lean-based model for the emergency department of a public university hospital in Malaysia, and evaluate its impact on operational performance and cost efficiency. Guided by a Design and Development Research (DDR) framework, the study was conducted in three phases: needs analysis, model design and development, and model evaluation. A structured needs analysis combining performance data, workflow mapping, stakeholder input, and observation identified critical bottlenecks within the Green Zone. A Lean-based model was developed through value stream mapping and underwent expert validation. A quasi-experimental Interrupted Time Series (ITS) design analysed daily median triage-to-registration time (TTR), arrival-to-consultation time (ATC), and length of stay (LOS) across two six-month periods (n=363 time points) using segmented regression with autoregressive integrated moving average (ARIMA) error structures. Implementation was associated with a statistically significant immediate reduction in TTR of 0.95 minutes (95% CI -1.36 to -0.53; p<0.001). Reductions in ATC (-25.37 minutes; 95% CI −90.05 to 39.32; p=0.44) and LOS (-7.72 minutes; 95% CI -19.50 to 4.07; p=0.20) were not statistically significant. Total operating costs decreased by 2.63% despite a 19.5% increase in patient volume. Cost per patient declined from RM855.10 to RM696.56 (-18.5%; p=0.19), and cost per patient-hour from RM283.16 to RM233.80 (-17.4%; p=0.14). These findings provide empirical evidence that a systematically designed Lean intervention can produce measurable front-end flow improvements while enhancing cost efficiency under increased service demand. This study provides a reproducible framework for system- level redesign in resource-constrained ED settings. Keywords: Lean healthcare; Emergency Department; Quasi-experimental; Interrupted Time Series; Economic evaluation