Is there a list anywhere of IS conversion factors for different labs? I've been trying to find out the CF for my lab (Barts) since the results I get from there seem to be 'raw' (but might not be), while the Hammersmith ones I get are IS (I'm told). I've had no luck in getting it - generally fobbed off by doctors there talking about raw ratios which I am sure are important but I don't see how I can compare PCRs against ELNet guidance without an IS conversion.
David.
Hi David,
You're absolutely right, you cannot convert to IS without the local lab (in this case Bart's) giving you their conversion factor. If I were you I would take the HH labs results- if they are indeed given on the IS- and use them as your standard. You can check whether they are given on the IS by contacting the HH lab and asking if they do give your result converted to the IS.... I can try to find out for you or you can contact HH yourself?
The method for finding a labs conversion factor is on page 17 of the Q-PCR booklet with 3 examples. However you will need the Bart's lab to be more communicative!
Sandy
Thanks Sandy,
The results I get from HH are IS - I know that. I just don't get them done as frequently as those from Barts. That said, blood went over to HH just the other day so I should get a result from there soon.
I'll have to work harder on the Barts lab to get their conversation factor. None of the consultants / reg's seem to be up on it. Worryingly, the reg I spoke to at clinic the other day seemed to find it news to her that you would need a conversion factor!
For example, back this time last year I got a 0.04% from HH and a 0.37% from Barts. Quite a different raw figure! That said, I'm now down to a 0.05% at Barts, so hopefully that is a good omen for the next HH result.
David.
The HH results are given on the front sheet as a IS level although the listings on your page of pcr results are on there own standard.
For the IS Standard for the Hammersmith the conversion factor is to multiply by 0.299
