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RegisterQC medium: short answer [Bioanalytics]
Hi haydonat and Helmut and others,
ok, the guideline suggests that medium QC is midway between LLOQ and ULOQ, but to be honest I don't think it is fully unreasonable to use a mean ("Medium") for QC that is closer to LLOQ than ULOQ. This is because it is not uncommon to see more observed values closer to the LLOQ than to the ULOQ. I am basing this on typical PK-profiles (often rapid increase towards Cmax, then rapid decrease) and intuition.
Add to this that a safety factor if often included for the ULOQ (expected Cmax plus a nice generous bit) to minimise the need for dilutions.
Thus I would expect a medium closer to LLOQ than ULOQ to be reflective of more samples than if it was just the average, and I would on that basis argue that such a QC value would be more relevant.
If the medium then should be calculated as the geometric mean or via some other sneaky method to make sure the QC level is representative of typical or expected samples, that of course remains to be discussed. Likewise, if someone has scientific arguments why a medium QCs should not reflect typical or expected values then I'd be happy to learn.
ok, the guideline suggests that medium QC is midway between LLOQ and ULOQ, but to be honest I don't think it is fully unreasonable to use a mean ("Medium") for QC that is closer to LLOQ than ULOQ. This is because it is not uncommon to see more observed values closer to the LLOQ than to the ULOQ. I am basing this on typical PK-profiles (often rapid increase towards Cmax, then rapid decrease) and intuition.
Add to this that a safety factor if often included for the ULOQ (expected Cmax plus a nice generous bit) to minimise the need for dilutions.
Thus I would expect a medium closer to LLOQ than ULOQ to be reflective of more samples than if it was just the average, and I would on that basis argue that such a QC value would be more relevant.
If the medium then should be calculated as the geometric mean or via some other sneaky method to make sure the QC level is representative of typical or expected samples, that of course remains to be discussed. Likewise, if someone has scientific arguments why a medium QCs should not reflect typical or expected values then I'd be happy to learn.
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Pass or fail!
ElMaestro
Pass or fail!
ElMaestro
Complete thread:
- determining the QC medium haydonat 2012-10-18 00:26 [Bioanalytics]
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- QC medium: short answer Helmut 2012-10-18 16:14
- QC medium: short answerElMaestro 2012-10-18 16:51
- QC medium: lengthy answer Helmut 2012-10-19 15:47
- QC medium concentration in 2014 Debbie 2014-06-10 19:42
- ~geometric mean of range Helmut 2014-06-17 14:30
- ~geometric mean of range nobody 2014-06-17 14:49
- ~geometric mean of range Helmut 2014-06-17 15:11
- ~geometric mean of range nobody 2014-06-17 18:26
- ~geometric mean of range Helmut 2014-06-18 16:07
- compromise ElMaestro 2014-06-18 17:43
- compromise Ohlbe 2014-06-18 20:00
- compromise Helmut 2014-06-19 01:13
- compromise Ohlbe 2014-06-19 11:15
- compromise Helmut 2014-06-19 01:13
- compromise Ohlbe 2014-06-18 20:00
- compromise nobody 2014-06-19 14:10
- compromise ElMaestro 2014-06-18 17:43
- ~geometric mean of range Helmut 2014-06-18 16:07
- ~geometric mean of range nobody 2014-06-17 18:26
- ~geometric mean of range Helmut 2014-06-17 15:11
- ~geometric mean of range nobody 2014-06-17 14:49
- ~geometric mean of range Helmut 2014-06-17 14:30
- QC medium concentration in 2014 Debbie 2014-06-10 19:42
- QC medium: short answer Helmut 2012-10-18 16:14
Ing. Helmut Schütz