Iron plays important functions in the body such as the formation and functioning of hemoglobin and it’s disorders are among the most common diseases of human1. It is essential to ensure that its levels determination through laboratory tests are accurate and precise. The participation of laboratories in the External Quality Assessment (EQA) allows the increases of the quality level of the laboratory results and improvement of its performance.2This study was developed in the Portuguese Nacional EQA Program (PNAEQ) concerning the laboratories results from the Clinical Chemistry Scheme. The main objective of this study was to evaluate and improve the sigma quality level regarding the Iron parameter and reduce the variability of the laboratories results participating in the EQA program of Clinical Chemistry of the Nacional External Quality Assessment Program (PNAEQ). The mean Sigma quality level indicated that the Ferrozine method had a better performance compared with Ferene S method. Half of the control samples had a sigma quality level higher than 3.0, which is set as the minimum acceptable quality.3 Despite of the improved of the Sigma quality level in the Pilot Test, the results demonstrated a need to improved the analytical process performance and to identified more potential causes and implement new improvement actions. It becomes necessary to raise awareness with the laboratories, improving the Pilot Test participation frequency, resulting in a recurrent and current assessment of the laboratory activity performance. Developing Six Sigma projects on a periodic basis is important for continuously and progressively increasing the level of Sigma quality in laboratory examinations. The main advantage of quality assessment on the sigma scale is providing evidence of overall laboratory performance, taking into account random and systematic errors.N/
