Empirical Studies (Outcomes: Acute Care, CHC, ED, ICU, Lab, Outpatient, Pharmacy)

Primary research articles assessing health, process, satisfaction, and cost outcomes of Lean in healthcare organizations

Acute Care (Medical/Surgical)

Ellingson K., Muder R.R., Jain R. et al. (2011). ‘Sustained Reduction in the Clinical Incidence of Methicillin-Resistant Staphylococcus aureus Colonization or Infection Associated with a Multifaceted Infection Control Intervention’, Infection Control and Hospital Epidemiology, 32 (1), pp. 1–8.

Interrupted time-series analyses were used to assess the impact and sustainability of a multifaceted intervention to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission over 3 chronologically overlapping phases at 1 U.S. hospital. The researchers examined individuals admitted to acute care units between October 1, 1999 and September 30, 2008. They found that after the intervention’s initiation in 2001, clinical incidence of MRSA colonization decreased, culminating in a total 61% decrease in the 7-year post-intervention period (p=0.02). The intervention consisted of 3 elements: 1) Lean and positive deviance change strategies to promote adherence to infection control protocol, 2) enhanced emphasis on hand hygiene and environmental disinfection, and 3) active surveillance testing of anterior nares and open wounds within 48 hours after admission to identify patients asymptomatically colonized with MRSA for prompt initiation of contact precautions. The study demonstrated a significant and sustained intervention-associated reduction in hospital-wide MRSA transmission, as defined by clinical incidence of MRSA colonization or infection.

Community Health Clinics (CHCs) & Rural Facilities

Kanamori, S., Sow, S., Castro, M. et al. (2015). ‘Implementation of 5S management method for lean healthcare at a health center in Senegal: a qualitative study of staff perception’, Global Health Action, 8.

The authors attempted to assess the Lean 5S management method’s effect on the workplace, healthcare process and outcomes, and applicability to resource-poor settings based on a pilot intervention of the 5S program in a Senegal health facility. They conducted a qualitative study by interviewing 21 health center staff members 1 year after the pilot intervention. Staff were asked about their views on the changes brought on by the 5S program in their workplace, daily routines, and services provided. Interviews were then transcribed and organized by emerging themes using thematic analysis in the coding process. The authors concluded that the 5S management method was perceived to have improved the quality of healthcare services and staff motivation in a resource-poor healthcare facility with a disorderly work environment in Senegal.

Snyder, K.D. and McDermott, M. (2009). ‘A Rural Hospital Takes on Lean’, Journal for Healthcare Quality, 31 (3), pp. 23-28.

This paper discussed the journey a 99-bed rural hospital took to integrate Lean into its organization and the outcome. The first year focused on the development of healthcare-specific Lean training modules, honing change management skills and leadership training. The hospital CEO and senior management invited 52 personnel (a mix of managers, nurse supervisors, line staff, and business personnel) to be a part of the program. Team expectations included attendance at all workshops, participation in a Lean project, and willingness to be a trainer or mentor to future Lean teams. Senior management agreed to provide support to all team members, including time and scheduling commitment and assistance in reducing or eliminating barriers for success. Change management workshops were delivered by certified university facilitators. The hospital CEO defined 3 parameters for projects: meet the organization’s strategic mission, include a 70% clinical and 30% nonclinical project mix, and involve no large requests for new money. The first Lean project aimed to decrease time spent obtaining supplies from a particular supply room from entry to exit on the morning shift by 20%. Time savings of 6 minutes, 53 seconds/supply search and annual cost savings of $9851/year were observed. A second project aimed to reduce ED waiting times by 10% and resulted in 68 minute time savings from 230 minutes to 162 minutes after Lean. The third and last project worked to meet a standard the clinical information be documented in e-medical records within 30 minutes post-nursing assessment. Improvements resulted in reducing the average time that elapsed between taking a patient’s vitals and inputting data into the EMR from a high of 538 minutes after to within 30 minutes of taking the patient’s vitals. The authors found that these projects showed that similar improvements from Lean are possible within all aspects of the medical community.

Weaver A., Greeno C.G., Goughler D.H. et al. (2013). ‘The impact of system level factors on treatment timeliness: utilizing the Toyota production system to implement direct intake scheduling in a semi-rural community mental health clinic’, Journal of Behavioral Health Services Research, 40 (3), pp. 294–305.

Previous research consistently demonstrated that treatment timeliness (the amount of time between consumers’ initial contact with mental health service providers and their first appointment) was an important predictor of whether consumers attended their appointments. Lean was thus evaluated as a method to change intake procedures on treatment timeliness within a semi-rural community mental health clinic. A team of administrators, clinicians, and staff conducted value stream mapping of the clinic’s intake process and identified non-value added elements, potential sources of error, and waste. They then designed a new intake process based on Lean that focused on specifying the process in detail, with unambiguous connections between each step, and a simple and direct pathway. The team found it important to understand average intake/day, times of day with heaviest intake, and months with higher intake volume in order to determine when more help was needed and how much time intake staff would have for other duties. For data analysis, 100 randomly selected cases opened the year before the change and 100 randomly selected cases opened the year after the change were examined using analysis of covariance (ANCOVA). The authors found that changing intake procedures using Lean significantly decreased the average number of days consumers waited for appointments from 11 days to 8 days (p = .03).

Emergency Department (ED)

Burström, L., Letterstål, A., Engström, M.L. et al. (2014). ‘The patient safety culture as perceived by staff at two different emergency departments before and after introducing a flow-oriented working model with team triage and lean principles: a repeated cross-sectional study’, BMC Health Services Research, 14, pp. 296.

A repeated cross-sectional study was conducted to determine the patient safety culture in a county hospital ED and a university hospital ED. The authors used the Hospital Survey On Patient Safety Culture questionnaire to assess this culture before and after a quality improvement project using Lean principles and team triage at both EDs. At the county hospital, a difference between baseline and follow-up was observed in three dimensions. For two of these dimensions, teamwork within hospital and communication openness, a higher score was measured at follow-up; information and support to staff at adverse events was rated lower at follow-up. At the university hospital, 3 dimensions were found as lower at follow-up: staffing, information and support to patients at adverse events, and patient safety grade. A higher score was measured at follow-up for teamwork across hospital units and teamwork within hospital. Overall, the authors concluded that the improvement project led to changes in self-estimated patient safety culture, with improvements in perceived teamwork and communication openness, and declines in perceived information and support to staff during adverse events.

Chan, H., Lo, S., Lee, L. et al. (2014). ‘Lean techniques for the improvement of patients’ flow in emergency department’, World Journal of Emergency Medicine, 5 (1), pp. 24–28.

A quantitative, pre- and post-Lean design study was conducted to evaluate a series of Lean methods implemented to improve admission and blood result waiting times at an ED. These methods included structured re-design process, priority admission triage (PAT) program, enhanced communication with medical department, and use of new high sensitivity troponin-T (hsTnT) blood test. Triage waiting time, consultation waiting time, blood result time, admission waiting time, total processing time and ED length of stay were compared before and after implementation. After Lean implementation, the triage waiting time and end waiting time for consultation were significantly decreased. The admission waiting time to the emergency medical ward (EMW) was also significantly decreased from 54.76 minutes to 24.45 minutes after implementation of the PAT program (P<0.05). The authors concluded that Lean management can improve the patient flow in ED, with adherence to lean principles being crucial to enhance high quality emergency care and patient satisfaction.

Dickson, E.W., Anguelov, Z., Vetterick, D. et al. (2009). ‘Use of Lean in the Emergency Department: A Case Series of 4 Hospitals’, Annals of Emergency Medicine, 54 (4), pp. 504-510.

Participants in 2 academic and 2 community EDs that instituted Lean as their single process improvement strategy made observations of their behavioral changes over time. They also measured the following metrics related to patient flow, service, and growth from before and after implementation: time from ED arrival to ED departure (length of stay), patient satisfaction, percentage of patients who left without being seen by a physician (2 EDs), the time from ordering to reading radiographs (1 ED), and changes in patient volume. The authors found that one year post-Lean, length of stay was reduced in 3 of the EDs despite an increase in patient volume in all 4. Each observed an increase of patient satisfaction lagging behind by at least a year. They additionally noted that the narratives indicate that the closer Lean implementation was to the original Toyota principles, the better the initial outcomes. The immediate results were also greater in the EDs in which the frontline workers were actively participating in the Lean-driven process changes. A factor that considerably affected the outcomes in the second and third year post-implementation was the level of continuous leadership commitment to Lean.

El Sayed, M.J., El-Eid, G.R., Saliba, M. et al. (2015). ‘Improving Emergency Department Door to Doctor Time and Process Reliability: A Successful Implementation of Lean Methodology’, Medicine, 94 (42), e1679.

This study aimed to determine the effectiveness of Lean management on improving emergency department (ED) door-to-doctor times at an academic, urban tertiary care hospital. The authors performed a before and after study at the ED after implementing a series of Lean-driven interventions over a 20-month period. A convenience sample from the pre-intervention phase (February 2012) was compared to another from the post-intervention phase (mid-October to mid-November 2013). Individual control charts were used to assess process stability. Post-intervention, a statistically significant decrease in mean door-to-doctor time (40.0 mins ± 53.44 vs 25.3 mins  ± 15.93, P < 0.001) was found. Length of stay of both admitted and discharged patients dropped from 2.6 to 2.0  hours and 9.0 to 5.5  hours, respectively. All other variables including emergency department visit daily volumes, hospital occupancy, and left-without-being-seen rates were comparable.

Ford A.L., Williams J.A., Spencer M. et al. (2012). ‘Reducing door-to-needle times using Toyota’s Lean manufacturing principles and value stream analysis’, Stroke, 43 (12), pp. 3395–3398.

Earlier tissue-type plasminogen activator (tPA) treatment for acute ischemic stroke was previously shown to improve the efficacy of tPA, urging national efforts to reduce door-to-needle times. To this end, the authors used Lean process improvement to develop a streamlined intravenous tPA protocol. A multidisciplinary team conducted value stream analysis (VSA) of the acute ischemic stroke patient pathway. 132 stroke patients treated with tPA before VSA and 87 patients treated with tPA after VSA were directly compared on baseline characteristics, protocol metrics, and clinical outcomes. VSA exposed several tPA protocol inefficiencies, which were then addressed through roll-out of a new protocol designed to minimize delays. Average door-to-needle time dropped 21 minutes from 60 to 39 minutes post-VSA (p < 0.0001), and the % of patients treated <= 60 minutes from hospital arrival increased from 52% to 78% post-VSA (p < 0.0001), with no change in hemorrhage rates. The paper concluded that future studies should be implemented to determine whether this intervention is sustainable across various hospital settings.

Kelly A., Bryant M., Cox L. et al. (2007). ‘Improving emergency department efficiency by patient streaming to outcomes-based teams’, Australian Health Review, 31 (1), pp. 16-21.

A pre-post study was conducted at an emergency department (ED) at a 300-bed, community teaching hospital in Melbourne, Australia. It aimed to describe the procedure and results of a process redesign based on task analysis and Lean thinking approaches aimed at improving ED efficiency. The study compared 12-month periods before and after the process redesign for total episodes of ambulance bypass, waiting times (overall and by triage category) and total ED time (overall and by triage category). Time data were then analyzed using non-parametric methods. While the years were broadly comparable, there was an 8.4% increase in total hours of care delivered (a marker of ED workload) in the year after the change. Episodes of ambulance bypass reduced by 55% (120 v. 54). There were statistically significant waiting time reductions for triage categories 3 and 5 (median reductions 5 and 11 minutes respectively). There was an increase in total ED time for triage category 3 (median increase 7 min) and a decrease for categories 4 and 5 (median reduction 14 and 18 min, respectively). The authors concluded that process redesign using task analysis and Lean could improve ED efficiency.

Mazzocato P., Holden R.J., Brommels M. et al. (2012). ‘How does Lean work in emergency care? A case study of a Lean-inspired intervention at the Astrid Lindgren Children’s hospital, Stockholm, Sweden’, BMC Health Services Research, 12 (1), pp. 28.

The authors aimed to address the gap in knowledge of how and why lean interventions succeed or fail. They utilized a mixed methods design to evaluate an in-depth case study of a Lean-inspired intervention in a Swedish hospital, particularly in its pediatric Accident & Emergency (A&E) Department – the largest of 3 pediatric A&Es in Stockholm. The study aimed to compare performance before and after lean intervention as well as explain how and why lean worked. The hospital’s weekly average data on waiting times and patient volume were collected for 52 weeks before and 104 weeks after Lean implementation for quantitative analysis. Additionally, qualitative data from interviews and documents were retrospectively collected from the intervention-planning phase and prospectively collected during the implementation phase. Analysis of variance (ANOVA) was used to assess differences in performance pre- and post-Lean, revealing an increase in % of patients completing their A&E visit within 4 hours from 67% to 80% [95% CI (65.5, 69.7), (78.2, 82.4)] that was maintained 2 years after the intervention. Average time to first physician consultation also decreased by 24% from 67 to 51 minutes [95% CI, (61.7, 71.5), (46.5, 56.3)] and was sustained 2 years post-Lean at 54 minutes [95% CI, (49.4, 59.2)]. The authors explained that Lean was effective because it reduced work ambiguity, created clear connections between caregivers who were dependent on each other, developed seamless and uninterrupted flow, and enabled continuous improvement through worker empowerment. Barriers to greater improvements from Lean were cited: these were job mismatch, discomfort with being monitored or with inter-professional collaboration, and some employees’ distance from change-related decision-making, leading to a feeling of being inadequately informed. The authors suggested further research into which Lean changes contribute most to performance improvement, claims of contextual conditions critical to further success, and the effects of Lean on employee working conditions.

Murrell, K.L., Offerman, S.R., Kauffman, M.B. (2011). ‘Applying Lean: Implementation of a Rapid Triage and Treatment System’, Western Journal of Emergency Medicine, 12 (2), pp. 184-191.

Lean principles were used to implement emergency department (ED) process improvements in 1 U.S. hospital, leading to the development of a Rapid Triage and Treatment (RTT) system. A retrospective, observational study was then conducted comparing electronic medical record data 6 months before and after implementation to determine whether Lean principles had an effect on ED metrics. The researchers found that changes in ED processes using Lean thinking and available resources improved efficiency. Mean ED length of stay was reduced by 36 minutes and the % of patients leaving without being seen by a doctor was reduced from 4.5% to 1.5% (95% CI). Months prior to any changes, weekly process improvement meetings with front-line staff and department leadership were conducted to gain staff input and plan process changes. Value stream mapping was used to analyze the flow of patients through the ED. Non-value-adding steps were identified and then streamlined to remove waste; weekly process meetings continued after implementation to constantly re-evaluate and modify as needed. The researchers emphasized staff and physician involvement throughout the process.

Ng, D., Vail, G., Thomas, S. et al. (2010). ‘Applying the Lean principles of the Toyota Production System to reduce wait times in the emergency department’, Canadian Journal of Emergency Medicine, 12 (1), pp. 50-57.

In recognition of patient wait times, and deteriorating patient and staff satisfaction, the authors set out to improve these measures in the emergency department (ED) without adding any new funding or beds. Lean techniques such as value stream mapping, just-in-time delivery techniques, workplace organization, reduction of systemic wastes, use of the worker as the source of quality improvement, and ongoing refinement of process steps formed the basis of the project. This resulted in major improvements in departmental flow without adding any additional ED or inpatient beds. The mean registration to physician time decreased from 111 minutes to 78 minutes. The number of patients who left without being seen decreased from 7.1% to 4.3%. The length of stay (LOS) for discharged patients also decreased from a mean of 3.6 to 2.8 hours. Lastly, an improvement in ED patient satisfaction scores was noted following the implementation of Lean principles.

Vermeulen M.J., Stukel T.A., Guttmann A. et al. (2014). ‘Evaluation of an Emergency Department Lean process improvement program to reduce length of stay’, Annals of Emergency Medicine, 64 (5), pp. 427–438.

Researchers sought to determine the effects of a Lean Emergency Department (ED) process improvement program on ED wait times and quality of care. They directed a retrospective cohort study of all ED visits at program and control sites during 3 waves from April 2007 to June 2011 in Ontario, Canada. The authors then conducted time series analyses comparing pre- and post-Lean implementation at program sites as well as difference-in-differences analyses comparing changes in program sites versus control sites. They found that while median ED waiting times did decrease at program sites, those benefits were diminished or disappeared when compared to control sites, which were exposed to system-wide initiatives such as public reporting and pay-for-performance. Further research was suggested to evaluate the effectiveness of Lean methods in the ED before warranting widespread use.

Intensive Care Unit (ICU)

Muder R.R., Cunningham C., McCray E., et al. (2008). ‘Implementation of an industrial systems-engineering approach to reduce the incidence of methicillin-resistant Staphylococcus aureus infection’, Infection Control Hosp Epidemiol, 29, pp. 702-708.

A before-after intervention study was conducted to measure the effectiveness of a Lean approach to implementing a methicillin-resistant Staphylococcus aureus (MRSA) prevention program. The study took place in an ICU and a surgical unit in the Pittsburgh Veterans Administration hospital and included all patients admitted to these units. The MRSA prevention program was comprised of 4 elements: 1) the use of standard precautions for all patient contact, with emphasis on hand hygiene; 2) the use of contact precautions for interactions with patients known to be infected or colonized with MRSA; 3) the use of active surveillance cultures to identify patients who were asymptomatically colonized with MRSA; and 4) use of Lean to facilitate consistent and reliable adherence to the infection control program. The rate of healthcare-associated MRSA infection in the surgical unit decreased from 1.56 infections per 1,000 patient-days in the 2 years before the intervention to 0.63 infections per 1,000 patient-days in the 4 years after the intervention (a 60% reduction; P = .003). The rate of healthcare-associated MRSA infection in the ICU decreased from 5.45 infections per 1,000 patient-days in the 2 years before to the intervention to 1.35 infections per 1,000 patient-days in the 3 years after the intervention (a 75% reduction; P = .001). The combined estimate for reduction in the incidence of infection after the intervention in the 2 units was 68% (95% confidence interval, 50%-79%; P < .001).


Cankovic, M., Varney, R.C., Whiteley, L. et al. (2009). ‘The Henry Ford Production System: LEAN Process Redesign Improves Service in the Molecular Diagnostic Laboratory: A Paper from the 2008 William Beaumont Hospital Symposium on Molecular Pathology’, The Journal of Molecular Diagnostics: JMD, 11 (5), pp. 390–399.

Lean was used in a molecular diagnostic laboratory to assess inefficiencies and improve speed of result generation. Baseline data analysis revealed that the greatest challenge to timely result generation occurred in the pre-analytic phase of specimen collection and transport; as such, efforts focused primarily on re-designing pre-analytic processes using Lean principles. The lab’s goal was to complete greater than 90% of the molecular tests in less than 3 days. The authors stated that Lean processes resulted in fewer steps, approaching the ideal of a one-piece flow for specimens through collection/retrieval, transport, and different aspects of the testing process. Lean created a 44% reduction in molecular test turnaround time for tissue specimens, from an average of 2.7 to 1.5 days. In addition, extending Lean principles to clinician suppliers resulted in a markedly increased number of properly collected and shipped blood specimens (from 50 to 87%). These continuous quality improvements were accomplished by empowered workers in a blame-free environment and are now being sustained with minimal management involvement.

Isaac-Renton, J.L., Chang, Y., Prystajecky, N. et al. (2012). ‘Use of Lean Response to Improve Pandemic Influenza Surge in Public Health Laboratories’, Emerging Infectious Diseases, 18 (1), pp. 57–62.

Multidisciplinary response and rapid implementation of process changes based on Lean methods were used at a provincial public health laboratory in British Columbia, Canada, to improve laboratory surge capacity in the 2009 influenza H1N1 pandemic. In the face of a 10-fold increase in demand for influenza testing without approval for additional staff, the lab needed to improve efficiency by changing workflow processes. Before the onset of the pandemic, PHMRL staff had been trained in Lean methods, and many had participated in activities to enhance laboratory processes. A Lean Team comprising medical, scientific, senior, and bench-level technical staff and some administrative and support personnel was set up to apply Lean methods to the influenza laboratory workflow. They created a visually displayed value stream of all discrete steps in the lab workflow for influenza detection. Review of ‘waste’ steps was conducted and a kaizen session performed by lab staff, culminating in the creation of a scalable and standardized work process. Observed and computer simulating evaluation results from rapid process changes showed that use of Lean tools successfully expanded surge capacity, which enabled response to a 10-fold increase in testing demands.

Samuel, L., and Novak-Weekley, S. (2014). ‘The Role of the Clinical Laboratory in the Future of Health Care: Lean Microbiology’, Journal of Clinical Microbiology, 52 (6), pp. 1812–1817.

This article aimed to provide commentary on Lean’s applications to microbiology labs, while discussing at length the development and results of a Lean program at the HFHS Department of Pathology and Laboratory Medicine. In 2007, the HFHS Department of Pathology and Laboratory Medicine used a Lean management approach to consolidate 4 microbiology labs into 1 lab with a projected 55 full-time staff conducting 700,000 tests annually. In using this approach, the department was able to achieve consolidation and take on additional work during the integration process, without a comparable increase in staffing. The authors concluded that Lean management practices have brought standardization, savings, and quality to many different industries; Lean management practices within the clinical microbiology laboratory could help to address the many economic, political, and medical challenges that labs face today and in the future.

Outpatient Care

LaGanga L.R. (2011).‘Lean Service Operations: Reflections and New Directions for Capacity Expansion in Outpatient Clinics’, Journal of Operations Management, 29 (5), pp. 422–433.

A Lean process improvement project was implemented that aimed to increase capacity to admit new patients into a healthcare service operation system. Analysis of 1,726 appointments in outpatient services for the year before and after the project found a 27% increase in capacity to intake new patients and a 12% reduction in patient no-show rates as a result of changes in service processes from the improvement project.


Hintzen, B.L., Knoer, S.J., Van Dyke, C.J. et al. (2009). ‘Effect of lean process improvement techniques on a university hospital inpatient pharmacy’, American Journal of Health-System Pharmacy, 66 (22), pp. 2042-2047.

The effect of Lean process improvement on an inpatient university hospital pharmacy, the University of Minnesota Medical Center (UMMC), was evaluated. Workflow in the sterile products area (SPA) was improved through the creation of accountability, standard work, and movement toward one-piece flow. Increasing the number of IV batches decreased pharmaceutical waste by 40%. Through SPA environment improvements and enhanced workload sharing, two FTE technicians from the SPA were redistributed within the department. SPA waste reduction yielded an annual saving of $275,500. Quality and safety were also improved, as measured by reductions in missing doses, expired products, and production errors. In the inventory area, visual control was improved through the use of a double-bin system, the number of outdated drugs decreased by 20%, and medication inventory was reduced by $50,000. Benefits of this process included an estimated annual cost saving of $289,256 due to waste reduction, improvements in workflow, and decreased staffing requirements.