On repeating out-of-control quality control measurements in medical laboratories

QC repetition should therefore be regarded as an exception rather than a routine response to an out-of-control event. The objective of QC is not merely to generate acceptable control values but to ensure the reliability of patient results. A pragmatic approach includes: temporarily pausing the reporting of patient results; assessing potential pre-analytical and analytical issues; repeating QC only when a plausible non-analytical or transient technical explanation exists (as outlined above); and initiating a full investigation and appropriate corrective actions when QC rejection rules are met.