Reference Range and Waived Testing

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Hi, 

Our waived clinics have adopted a new HbA1c instrument and the manufacturer insert has a reference range for HbA1c that is different from our current accepted range. 

Do we have to adjust our range to the manufacturer’s? 

We are CLIA accredited for waived testing only. 

Thanks! 

7 Replies

Very frequently, different platforms give slightly different results for the same specimen for the same analyte.... 
Best course of action would be to run a comparison study between the old and new instruments.  You may find there is a clinically significant difference in results between the two platforms.  This would then require the reference range to be modified for the new platform when you go-live with it.

Hi, we typically do run an initial comparison study. My concern is if we are required to follow the manufacturer’s instructions then wouldn’t not adopting their stated reference range be considered a violation of that requirement, making the waived test a now high complexity test? 

Modifying the manufacturers reference range is not modifying *how* the test itself is performed per IFU. (Provided you do not extend the range outside of the manufacturer's stated AMR).  So, no, that would not change its category to a high complexity test.
You will want to have your documentation of how you determined what your reference range will is, (and signed by your Medical Director). 

Hi, great answer. Additional question. If the reference range is outside of the instrument AMR but the result would be reported as a < less than according to that AMR, would that be a problem? 

For instance, our reference range for HbA1c goes as low as 3.5% but the instrument only reads as low as 4%. Our options are to change our reference range, report out less than 4% if the instrument indicates so, or cancel the test and suggest testing via an alternative method. 

Correct.
If the stated manufacturer's AMR only when down to 4.0 but you reported the 3.5 that would make it high complexity.   Easiest solution to prevent this is to have it report <4.0 and yes, change your reference range.  I wouldn't cancel the test, it would have already been ran, costs accrued.... and you'd likely be giving them the result <4.0 without any documentation to the effect.  I would have a canned comment added to the effect if it was required to have more specific result than the <4.0,  XX test should be ordered.

The problem with changing our reference range is we are trying to maintain standardization amongst reference ranges with our core lab. Could you not just turn out <4 and keep the 3.5 reference range? I like the comment idea! 

I'm not entirely clear on how CLIA would interpret that, at a minimum I would expect regulatory to question the differences and you would have to respond.  I would expect that your patient care givers (physicians) would question this discrepancy as well.  Also, it goes without saying that trending patient results using different platforms should also be discouraged.

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