Regulatory Open Forum

Annex XIII, 2.3.2 of the IVDR mentions all the items that must be covered in the CPSP. One of them (point q) are ''decision algorithms''. What does the IVDR mean by this? And what would I be expected to write down here? When is something a software, and when is it a ''decision algorithm''? Can someone please elaborate on what manufacturers are expected to hand in here, and what the content of this section should be?

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Lisanne Karbaat
MSc.
Enschede
Netherlands
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Annex XIII, 2.3.2 of the IVDR mentions all the items that must be covered in the CPSP. One of them (point q) are ''decision algorithms''. What does the IVDR mean by this? And what would I be expected to write down here? When is something a software, and when is it a ''decision algorithm''? Can someone please elaborate on what manufacturers are expected to hand in here, and what the content of this section should be?

Hi Lisanne,

Agree with you that as worded in the Annex XIII for CPSP 2.3.2 point q is very vague - decision algorithm in a CPSP is very broad.  It could mean for example the algorithm to call a sample result based on positive and negative and internal control test results as part of the assay (perhaps these are not incorporated into software, or perhaps they are).  It could also mean as described by Rajeswari below discriminating between qualitative results by means of showing what constitutes 'positive' vs. 'negative' or describing it in terms of staining (i.e. number of minimal viable cells, staining and scoring interpretation, tumor proportion score, or %stain).  I believe this is left broad on purpose to cover the wide range of assay types within in vitro diagnostics.  

Kind Regards,

Annex XIII, 2.3.2 of the IVDR mentions all the items that must be covered in the CPSP. One of them (point q) are ''decision algorithms''. What does the IVDR mean by this? And what would I be expected to write down here? When is something a software, and when is it a ''decision algorithm''? Can someone please elaborate on what manufacturers are expected to hand in here, and what the content of this section should be?

Many thanks to you both!

So is my understanding correct if I say that the decision algorithm can be literally anything and any action that contribute to the making of a decision. For example for a PCR test, sample taking, sample preparation, running the analysis, setting a threshold and then comparing the Ct value results to those of a control. All of these together form the ''decision algorithm''. Part of this can be in software, but it does not necessarily has to be software. Any other factors influencing the decision (positive or not), but outside the PCR test itself, (for example other clinical data from the patient) are also part of the decision algorithm, because they influence the final positive/negative result. 

Correct? Or am I still missing something?

Hi Lisanne,

Agree with you that as worded in the Annex XIII for CPSP 2.3.2 point q is very vague - decision algorithm in a CPSP is very broad.  It could mean for example the algorithm to call a sample result based on positive and negative and internal control test results as part of the assay (perhaps these are not incorporated into software, or perhaps they are).  It could also mean as described by Rajeswari below discriminating between qualitative results by means of showing what constitutes 'positive' vs. 'negative' or describing it in terms of staining (i.e. number of minimal viable cells, staining and scoring interpretation, tumor proportion score, or %stain).  I believe this is left broad on purpose to cover the wide range of assay types within in vitro diagnostics.  

Kind Regards,

Annex XIII, 2.3.2 of the IVDR mentions all the items that must be covered in the CPSP. One of them (point q) are ''decision algorithms''. What does the IVDR mean by this? And what would I be expected to write down here? When is something a software, and when is it a ''decision algorithm''? Can someone please elaborate on what manufacturers are expected to hand in here, and what the content of this section should be?