The Evolution of Lean Six Sigma Research in Hospitals: Trends, Themes, and Future Directions

Abstract

In response to the increasing complexity of healthcare services, hospitals have adopted systemized approaches to enhance operational performance while ensuring safe, high-quality patient care. Lean Six Sigma (LSS) has been widely applied in healthcare settings to improve processes, such as patient flow, discharge procedures, and hospital length of stay. However, the overall development of LSS research in hospitals, including the evolution and interrelationships of key research themes, has not been comprehensively examined. This study aimed to explore the current landscape of hospital-based LSS research with respect to publication trends, major research themes, collaboration characteristics, and research gaps. A total of 70 publications indexed in the Scopus database between 2016 and 2025 were analysed using the keywords “Lean Six Sigma” AND “Hospital”. Bibliographic data were analysed using Bibliometrix in R and VOSviewer to examine publication trends, keyword co-occurrence networks, collaboration networks, and thematic evolution. The results showed that publications increased at an annual growth rate of 18.19% indicating growing interest in hospital-based LSS research. Research efforts were primarily focused on operational efficiency, particularly patient flow, discharge processes, and length of stay. Three interconnected research domains emerged: operational efficiency, clinical quality, and organisational performance. Identified research gaps included the limited integration of digital technologies, the underrepresentation of low- and middle-income countries, limited international collaboration, and relatively less attention to patient safety and patient-centred outcomes. Although hospital-based LSS research continues to expand, it remains predominantly oriented toward operational improvement. Future research should focus on integrating digital technologies, broadening the range of healthcare contexts studied, strengthening international collaboration, and addressing clinical, safety, and patient-centred outcomes.Keywords: Lean Six Sigma, Healthcare Quality Improvement, Operational Efficiency, Patient Safety, Hospital Process Management, Bibliometric Analysis, VOSviewer.