Lean Six Sigma to Reduce Healthcare-Associated Infections in Surgery

Montella and colleagues (2016) applied Lean Six Sigma (LSS) to reduce the risk of healthcare-associated infections (HAIs) in the surgery departments of the “Federico II” University Hospital in Naples. Their study, published in the Journal of Evaluation in Clinical Practice, is a clear example of how an industrial improvement method can be used to tackle a clinical quality problem.

Background and rationale

Monitoring and preventing HAIs is a priority for health systems, and particularly so in Italy, where healthcare accounts for more than 7% of GDP and about 80% of regional budgets. HAIs are a key indicator of healthcare quality, and reducing them improves both patient outcomes and resource use. Managerial tools are increasingly used in hospitals, although healthcare poses specific challenges: outcomes are hard to measure with standard indicators, many variables such as age and gender cannot be controlled, and care processes are variable and prone to human error. The hospital already used surveillance, epidemiological guidelines, procedures and training, and adopted LSS as part of an integrated infection-reduction strategy.

Aims

The study aimed to reduce the number of surgical patients colonised by sentinel bacteria and therefore at risk of HAI, to identify and implement corrective actions that improve the care process, to analyse the contribution of each risk factor to colonisation, and to reduce inpatient days.

The method: Lean Six Sigma and DMAIC

LSS combines Lean, which originated in Japanese manufacturing and focuses on process effectiveness and waste removal, with Six Sigma, which focuses on efficiency, variation and statistical control. The study followed the DMAIC cycle: Define, Measure, Analyse, Improve, Control.

Define. A multidisciplinary team of physicians from the Healthcare Directorate, biomedical and managerial engineers, and surgical nurses defined the problem. The dependent variable was colonisation by sentinel bacteria (at least one positive sample); independent variables included the number of procedures, DRG, total hospital days, preoperative days and age. A project charter, Gantt chart and SIPOC analysis set out the scope and process boundaries.

Measure. Data covered more than 20,000 surgical patients between January 2011 and December 2014, drawn from the departmental information system and the QUANI surveillance programme. In the preliminary phase, 43 of 11,555 patients (0.37%) were colonised, and mean total hospital stay was 45 days (SD 30.78), with a highly skewed distribution around 2σ.

Analyse. Control charts, histograms, chi-square and Fisher exact tests, and scatter plots were used to study risk factors. Pseudomonas aeruginosa was the most common sentinel organism. The number of procedures had the strongest association with colonisation and with longer stays. An Ishikawa diagram and a questionnaire to the Hospital Infection Committee grouped root causes into materials, processes, healthcare staff and management.

Improve. Corrective actions were selected using the study results, literature standards and expert opinion. They included reviewing perioperative antibiotic prophylaxis, adopting instrument sterilisation protocols, computer-based surveillance, clinical pathways and wound management protocols, preoperative screening and decolonisation, staff training, and hand hygiene and immunisation campaigns.

Control. A feedback system monitored the effect of the changes, using three process indicators: hospital days, appropriateness of diagnostic and therapeutic procedures, and days between admission and first procedure.

Results

The share of colonised patients fell from 0.37% before the intervention to 0.21% in the control phase. Mean hospital stay fell from 45 days (SD 30.78, around 2σ) to 36 days (SD 15.68, around 3σ), indicating both shorter and less variable stays.

Implications

The study shows that LSS can reduce HAIs and length of stay in surgical departments. Patients benefit from shorter stays and better care; hospitals benefit from lower costs and better quality. LSS also helps managers use limited resources rationally and offers a structured way to analyse, improve and monitor complex clinical processes from both clinical and economic perspectives. It complements, rather than replaces, surveillance, guidelines and staff training.

APA Reference:

Montella, E., Di Cicco, M. V., Ferraro, A., Centobelli, P., Raiola, E., Triassi, M., & Improta, G. (2016). The application of Lean Six Sigma methodology to reduce the risk of healthcare–associated infections in surgery departments. Journal of Evaluation in Clinical Practice, 22(6), 1198–1205. https://doi.org/10.1111/jep.12662