Appraisal of six sigma in pre-analytical phase of clinical biochemistry laboratory

Objectives: The aim of the study is to measure the performance of pre-analytical phase of a clinical biochemistry laboratory using sigma metrics and the six sigma scale. Materials and Methods: The study included documented data of blood sample rejection from March 2023 to February 2024 and follow-up data from March 2024 to August 2024. International Federation of Clinical Chemistry and Laboratory Medicine developed Quality Indicators (QIs) used are QI-9 Wrong tubes; QI-10 Hemolyzed samples; QI-11 Clotted samples; QI-12 Insufficient samples; QI-14 Damaged samples in transport; and QI-15 Mislabeled samples. Based on “Six Sigma Quality Design and Control” established by Dr. Westgard, the sigma metric was calculated for the above-mentioned QIs. Statistical analysis: Obtained data were entered and analyzed using Microsoft Excel 2021. Results: Out of 162,380 received samples, 547 samples were rejected as not satisfied with the sample acceptance criteria. The most common pre-analytical error in the observed QIs is hemolyzed samples (458), followed by insufficient sample volume (55). The Sigma score of QI-10 was determined to be 4.81, whereas QI-9, QI-11, QI-12, and QI-15 were well maintained and graded excellent. Following training sessions, the follow-up month revealed a sigma score of 4.98 for QI-10. Conclusions: Six sigma metrics are a competent means to measure the performance of pre-analytical QIs in a clinical biochemistry laboratory. The observed QIs were effectively managed (>4 σ).