Effect of Internal Quality Planning using Sigma Metrics in Lean Management of a Clinical Chemistry Laboratory: An Analytical Study

Abstract

Introduction: Across the globe, quality control systems serve as the foundation for providing accurate and precise results, and also immediate error detection. However, many laboratories adhere to uniform Quality Control (QC) rules for all parameters, which may result in unnecessary overspending. The present study aimed to establish individual control rules and determine the number of control measurements for each of the 10 parameters using Westgard Entgegen-Zusammen (EZ) Rules 3 software. The cost-effectiveness and benefits of applying these new rules were evaluated, alongside the lot-to-date, lot-to-lot, and company-to-company Coefficient of Variation (CV) for quality control materials. Aim: To assess the impact of sigma-metrics-based internal quality planning on lean management in a clinical chemistry laboratory. Materials and Methods: This cost-effective and cost-effective analysis study was conducted using commercially available quality control materials. It was done in the Department of Biochemistry in the Super Specialty Block (SSB) Biochemistry laboratory at Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India, from June 2020 to June 2022. Initially, the existing practices were scored. Using Westgard EZ Rules 3 software, OPSpecs charts and power function graphs were plotted using Westgard EZ Rules 3 software, and control rules and the number of control measurements for 10 parameters (Urea, Creatinine, Calcium, Phosphorus, Magnesium, Uric acid, Aspartate Transaminase (AST), Alanine Transaminase (ALT), Alkaline Phosphatase (ALP), and Total protein) were determined. Cost-effective and cost-benefit analyses were conducted using quality cost worksheets. A comparison of lot-to-date (month to month), lot-to-lot, and company-to-company CV was performed using Statistical Package for Social Sciences (SPSS) Software version 19.0. Results: In the present study, it was found that ALP, calcium, and magnesium followed the 13S rule, whereas the remaining 7 parameters followed the 13S/22S/R4S/41S/10X rule with two control materials. The study revealed a decrease in cost by 95.8%, 92.3%, and 81.5% for ALT, AST, and creatinine, respectively, and by 71.1%, 68.8%, 59.8%, and 54.9% for uric acid, phosphorus, total protein, and urea, respectively, if the new control rules were followed instead of the existing ones. ALP, magnesium, and calcium showed no cost difference, indicating that the current control rules were similar to the newly framed ones. Furthermore, there was no significant difference in lot-to-date (month to month), lot-to-lot, and company-to-company CV on QC rules for most parameters despite changing reagent lots. Conclusion: In conclusion, the study demonstrated that the control rules for each of the 10 parameters (Urea, Creatinine, Calcium, phosphorus, magnesium, uric acid, AST, ALT, ALP, and total protein), as well as the comparison of QC material CV, proved to be cost-effective.

Keywords

• analysis of variance
• bias
• calcium
• cost-effectiveness analysis