Statistical quality control: IQC management and troubleshooting errors

In the previous eight articles we developed an approach to internal quality control (IQC) using a tailored assay performance-oriented system. This included expectations of our methods and how we monitor them to assure ourselves those standards are being achieved. Next, we must decide on actions when processes deviate beyond expected variation. It is that subject – troubleshooting IQC failure – that concludes the series on statistical quality control (SQC).

Monitoring the process

Managing the review of IQC can be a challenge, particularly in larger 24/7 services with high levels of automation. Internal quality control will be run at any time, based on pre-set time intervals, number of samples, or as part of reruns following failure. Often, set times are favoured to coincide with shift changes and/or analyser maintenance. Reviewing results is easier. All quality control (QC) can be validated at a given time. Nevertheless, dedicated IQC review meetings help to maintain engagement with assay performance and detect, at an earlier stage, developing issues. Daily laboratory meetings are commonplace and are a suitable place for this to be discussed, as well as monthly review meetings. Escalation of poor performance through a predefined governance structure informs clinicians of developing issues.