How to Really Understand and Improve the System of Internal Quality Control and External Quality Assessment in the Accreditation Process of the Medical Laboratory?

Internal quality control (IQC) regarding process to monitor analytical stability has a long tradition in laboratory medicine. The satisfactory results with different quality specifications of the IQC ensure the acceptability of the examination results. Although the statistical IQC is satisfactory some problems exist, resulting in unreliable patients' results due several reasons (non-commutable control materials, lot to lot difference of reagents, false interpreting test results regarding autovalidation or autoverification, different analytical and clinical specifications or goals etc.). Therefore, the results and findings of IQC have to be connected with external quality assessment (EQA) in order to provide the system of measurement of uncertainty (MU) with correct interpretation of laboratory result and detection relevant and significant shifts and drifts in medical laboratory.