Posted by Sten Westgard, MS
The German Rilibak Goals have been updated. But what are the changes?
Here's the list of changes present in the 2014 Rilibak edition:
- Alkaline Phosphatase: RMSD reduced from 13% to 11%; EQA goal reduced from 21 to 18%
- CA 19-9 is gone! In its place, CA 15-3
- FSH has been added
- Lipase has been deleted
- pCO2: goals have been made more complex
- FT4: goals have been simplified
- Transferrin: RMSD goal reduced from 9.5% to 8.0%; EQA goal reduced from 15% to 12%
- FT3: RMSD goal reduced from 14.5% to 13.0%; EQA goal reduced from 24% to 20%
- Vancomycin: EQA goal reduced from 21% to 18.0%
The goals for analytes in urine and cerebrospinal fluid have not been changed at all.
Just to be clear, the RMSD stands for Acceptable % Root Mean Standard Deviation, a calculation unique to the Germans that frankly no one else uses. The second numbers, acceptable difference for interlaboratory comparison, are analogous to the total allowable error goals like those of CLIA.
While a few analytes have been added, some have been removed, which is unusual. More disappointing still is that the overall number of analytes is still only a subset of those methods which laboratories can run. Rilibak covers just 67 analytes in plasma, serum, and whole blood, while the "Ricos goals" cover more than 350. Even CLIA covers more than 80 analytes.
Still, it's good to see that the Rilibak aren't carved in stone. The bad thing about the CLIA goals is that they've never been updated since they were issued in 1992. This has lead to widespread mistrust of those goals.
Always a headache in choosing Allowable Total Errors (TEa and ALE) from different professional authorities or individual expert recommendations...
What is the acceptable/allowable total error, as simple as the plasma glucose measurements? e.g.,
<5.5% (Ricos, biological variation)
<6.9% (NACB guideline)
<8.0% (RCPAQAP)
<10% (CLIA PT Limits)
<15% (Rilibak, inter-lab)
What else?
Think about: A plasma glucose of 7.0 mmol/L
At 5.5% is 6.61-7.38 mmol/L
At 15% is 5.95-8.05 mmol/L
The question is: Are these errors clinically acceptable???
Posted by: Richard Pang | November 27, 2014 at 02:28 AM