Application of clinical goals and the Six Sigma model in the evaluation of quality control in Clinical Chemistry

Introduction: With the aim of providing clinically relevant results, the clinical laboratory must implement a sufficiently good internal quality control system in order to achieve analytical goals with the highest possible standards. Materials and methods: A retrospective, descriptive, and longitudinal study was performed in order to study the internal quality control results of the Clinical Chemistry area of a Mexican laboratory obtained during the period from July to December 2016. Results: The Clinical Laboratory Improvement Amendments (CLIA) goals of maximum total allowable error were achieved in 100% of the analytes studied. In the case of biological variation goals, desirable or optimal goals were achieved for in 89% of the analytes studied, with inferior results being obtained in these analytes with a low biological variability index. Finally, as regards the results of sigma values, our results varied considerably depending on the analytical specifications used, achieving the lowest values in those analytes with the lowest biological variability index. Conclusions: Based on our results we can suggest that an adequate quality control model in Clinical Chemistry could initially include the establishment of analytical specifications based on CLIA for those analytes with low biological variation, and the desirable goals of biological variation for the rest of the analytes. Both goals can be achieved by the instruments used in this study.