Hi everyone,

 

I am learning about instrument correlation right now, and am wondering a couple of things.

 

1. what parameters of a CBC must be monitored? I have heard that CAP only requires the WBC, RBC, HGB, HCT, PLT, and MCV but not the differential.

 

2. When you have a parameter failing the allowable error, where do you start? What is the best way to see which anaylzer is the one at fault for the fail? And once you establish, how do you get to match if you have done all the checks for maintance and QC is looking good for the faulting one...do you adjust the cal factor so they are alined?

 

3. When dealing with different manufacturers for your analyzer comparison, they should match the total allowed error regardless of type and brand of hemo analyzer?

 

 

Thanks for the help!

In general, you would need to correlate whatever is measured directly by the analyzer.  For hematology, that would be: WBC, HGB, RBC, MCV and PLT, along with the % diff (retics too, if those are reported).  If a correlation shows a significant variance for a particular parameter, you have to look at possibly changing it's reference range for the new analyzer.  Normal ranges need to be determined by a normal range study, which should be done with a new analyzer anyway.

 

Scott

I agree with SMiller.  I have a related question though.  I'm trying to learn Excel so I can make nice graphs of correlations for several reasons but I cannot seem to find a good reference with hospital lab examples to complete the task.  Sysmex was helping me with correlating instrument diffs to manual diffs but they seemed to be reluctant this time to help me.  They use PC evaluator I believe and so does Seimens which makes very nice pretty graphs but I "think" I can do the same thing with Excel.  If anyone uses excel can help me I'd appreciate it or perhaps point me to the correct reference.  If anyone uses pc evaluator is it worth the money.  My director says we can "try" to buy it if I thojught it was worth it, however, I'm sure the CFO would complain about the price.

Thanks

 I'm trying to learn Excel so I can make nice graphs of correlations for several reasons but I cannot seem to find a good reference with hospital lab examples to complete the task. 

 

If you go on the Westguard website - they have links to approved programs

 

https://www.westgard.com/downloads.html

Thanks Auntie-D