ỨNG DỤNG THANG SIX SIGMA VÀ CHỈ SỐ MỤC TIÊU CHẤT LƯỢNG TRONG QUẢN LÝ CHẤT LƯỢNG XÉT NGHIỆM HOÁ SINH LÂM SÀNG

Abstract

Background: The Six Sigma scale aids in evaluating the analytical performance of clinical biochemistry testing methods, while the Quality Goal Index (QGI) further enhances laboratory testing quality. Objectives: To assess the analytical performance of seven biochemical tests (Glucose, Urea, Creatinine, Uric Acid, AST, ALT, and Calcium) and to identify potential issues within the laboratory using the QGI index. Materials and methods: A cross-sectional descriptive study was conducted. Sigma metrics were calculated based on TEa%, CV%, and Bias% derived from internal quality control (IQC) and external quality assessment (EQA) data collected over three months. The QGI index was determined using sigma values and CV%. Results: According to the Biological Variation database, ALT exhibited the highest analytical performance (16.7) at IQC level 2, whereas Creatinine demonstrated the lowest performance (2.5) at IQC level 1. Based on CLIA criteria, Glucose and Uric Acid achieved “World-Class” analytical performance at IQC level 1, while Urea was classified as “Unacceptable” at both IQC levels. Tests with QGI < 0.8, including Creatinine and Calcium (IQC level 1) and Uric Acid (IQC level 2), indicated issues with imprecision. Tests with QGI between 0.8 and 1.2, including Urea (IQC level 1) and Urea, Calcium (IQC level 2), showed both imprecision and inaccuracy. QGI > 1.2 for AST (IQC level 1) reflected problems with inaccuracy. Conclusions: The application of Six Sigma and QGI effectively identified performance issues, particularly in Creatinine, Urea, and Calcium tests. This enables the development of appropriate quality control procedures and ensures more reliable results for patient care.