Posted by Sten Westgard, MS
Earlier this month, we posted about an interesting survey of laboratory quality control practices. The study was so interesting, it's worth revisiting the topic.
Just to review, here's the citation:
What we'd like to point out in this post is what happened after the survey was completed. Based on the results, the authors of the study proposed a set of standards for quality control for the laboratories in their region:
- IQC policies should cover 24 hour period.
- Target values and ranges for IQC material should be assigned locally for each instrument. Manufacturer target levels and ranges should not be used.
- Labs should use IQC material from a third party source.
- Use EP5-A2 or equivalent to determine IQC values within each individual laboratory.
- Encourage method specific rules (single and multi) based on the required quality of the assay, and known method bias and coefficient of variation.
- Discourage inappropriate use of single rules, but when used ensure they have required degree of error detection.
- Review grades of staff accepting and rejecting IQC
- If IQC policies are robust, and the correct IQC with appropriate error detection is used, failed IQC should not be accepted (e.g. to continue processing patients' samples).
- For analysers that have multiple modules, each module should be assessed individually with IQC on each assessment.
For frequent visitors and readers of Westgard Web, few of these proposed standards should come as a surprise.
Just to find out a bit more, we contacted the authors of this study to ask about the reaction and impact of their findings. Dr. David Housley was gracious enough to send this reply:
[personal communication, 3/5/2009]
It's heartening to see such recommendations coming from an Audit and Quality Assurance Group. Somewhere in the world QC is still being taken seriously. If a similar survey of US laboratories were conducted and found similar results, I'm afraid our US regulators would generate the opposite recommendations: that IQC is too hard and thus, we need to dismantle IQC and replace it with something that the laboratories can more easily achieve (i.e. Equivocal QC).