It starts so innocently with a question to colleagues – in this instance a post on the AACC Artery community. Yet it highlights one of the complexities in laboratory testing: given the lack of definitive guidance, we all must rely on our best judgement to do what is best for patient care. Everyone has his or her go-to references, such as a textbook, colleague or favorite search engine (the latter only hopefully a starting point, not the finish line). In this specific example, the question is “what constitutes a major move regarding laboratory instrumentation?”
We start with the easiest – everyone knows a major move would include a different building or even a different floor of the same building. From there, however, it gets more complicated. Same room but a different location (e.g., North Wall to South Wall)? Only a few feet to the right or left? What about a few inches or relocation of a subcomponent of an instrument? In civil law, the concept of the “Reasonable Person” is pervasive in determining legal consequences. Applying this same “Reasonable Person” idea to the current scenario, what might a “Reasonable Lab Director” or RLD be expected to do?
As an example, a laboratory moved an instrument a few feet to place a new system. Based on the above, this constitutes a minor move and perhaps our RLD would use the “mini validation” concept proposed by some using a handful of QC points and a small number of patient comparisons. That said, this RLD revalidated for precision and accuracy using control materials, AMR, and patient correlations for all tests. Some days later, a beta hCG was reported that raised concern about a possible miscarriage. It turned out that the buffer used to dilute the beta hCG was at the furthest ancillary position and was not being pipetted. The RLD called for a repeat of all beta hCG samples tested since the move occurred. Words of Wisdom from this RLD: Consider the instrument design, reagent positions, etc. when designing your mini-validation should one choose to truncate the revalidation.
In this Artery thread, the argument was made that determining nothing bad happened to the instrument during a move is often inappropriately entangled with if an assay works after a move. Certainly, it is important that an assay still works after a move but revalidating an assay does not necessarily address the concerns of overall instrument performance. However, there is common guidance available in what is done during an instrument installation, which is by definition part of a “move”: the IQ/OQ/PQ process. In simple terms, this process helps to answer three fundamental questions:
Installation Qualification: Was the instrument installed according to manufacturer's defined specs?
Operational Qualification: Does the instrument perform according to manufacturer's defined specs?
Performance Qualification: Does the instrument perform according to the laboratory's defined specs?
It is not difficult to argue that running the assay and assuming QC informs us that everything is fine may be missing the mark. For low volume tests, it may be weeks before QC identify an issue, if ever. In addition, given the wide range in acceptance criteria for validation experiments (yes we all do accuracy, but what is the de facto acceptable slope?) it is easy for a post-move error to go unaddressed.
Using the above IQ/OQ/PQ criteria, a lab can easily determine if the move compromised any functions of the instrument based on function checks, daily maintenance, or other historic data. Modifying the original IQ/OQ/PQ process leverages vendor expertise and lab expertise to ensure the equipment is working - separate from assay performance.
The above occurrence is unfortunately not unique. Even applying the RLD standard we are sure to find an error in what others would consider reasonable. Instrument moves happen pretty fast. If we don't stop and look around once in a while, we could miss it.
The Artery is a private online community of laboratory medicine professionals accessible only to AACC members. Forums on the Artery offer collaborative spaces for AACC members to ask questions, share knowledge, and refine ideas by connecting with their peers.