Application of Six Sigma Methodology in Clinical Biochemistry Laboratories: A Mini-review

Preanalytical PhaseThe preanalytical phase includes patient identification, specimen collection, labeling, transport, and storage.Errors during this phase commonly arise from incorrect patient identification, improper collection techniques, hemolysis, delayed transport, or inappropriate storage conditions.These errors may significantly affect biochemical measurements even before analysis begins.Effective QA measures in this phase include standardized protocols, staff training, adherence to labeling procedures, and continuous monitoring of specimen handling practices. Analytical PhaseThe analytical phase involves the measurement of analytes using calibrated instruments and validated methodologies.Quality control procedures are central to ensuring accuracy and precision.Internal QC samples with known concentrations are analyzed alongside patient samples to detect systematic and random errors.Statistical tools such as Levey-Jennings charts and Westgard rules assist in identifying trends, shifts, and outliers.Analytical QA also includes instrument calibration, reagent validation, and periodic maintenance. QualIty assurance I n clInIcal BIochemIstry laBoratorIesQuality assurance in clinical biochemistry is a comprehensive system designed to prevent, detect, and correct errors throughout the testing cycle.It integrates procedural standardization, internal quality control (QC), external quality assessment, documentation systems, and continuous performance monitoring.