Internal Quality Control SOP template (ISO 15189:2022)

An internal quality control procedure explains how the laboratory monitors examination performance during routine work and decides whether patient results can be released. It brings together control material selection, scheduling, review and response to unacceptable performance. The document should reflect the examinations and instruments in use rather than apply one unexplained control frequency or rule to every method.

A good version identifies suitable control levels, preparation and storage conditions, lot changes and the basis for assigned targets and limits. It explains which acceptance rules apply, who reviews control results and when controls must be assessed relative to patient testing. Include how trends, shifts and other concerning patterns are considered even when an individual result is not outside a limit.

The failure pathway needs particular care. Describe when testing or reporting stops, how the problem is investigated and what evidence permits work to restart. Repeating a control without understanding the result should not become the default instruction. The procedure should also address patient results generated since the last acceptable performance check, including review and escalation where necessary. Records must link control observations, decisions, troubleshooting and authorisation to resume routine work.