I have previously commented that many CLSI evaluation standards at some point ask the question “is the assay performance good enough” and answer that question with “it’s up to the lab director.”
The problem is that lab directors are not clinicians and do not treat patients. Note that most lab directors are either PhD clinical chemists or pathologists and although pathologists are MDs, they are not clinicians because they do not treat patients.
Of course, lab directors do have a great deal of knowledge about assay performance but in my experience – especially in working on CLSI standards – lab directors tend to focus on analytical errors whereas only total error is of importance to clinicians and the source of errors that contribute to total error is a combination of analytical, pre- and post-analytical error.
So how should the “is it good enough” question be answered? An example appeared recently in the literature (1) where clinicians were surveyed as to what size glucose meter errors would start to cause problems for diabetics under several scenarios. The results provided limits for a glucose meter error grid. Note that there was no attempt to identify error limit sources – the limits simply reflect the observed error, regardless of its source.
- Klonoff DC, Lias C, Vigersky R, et al The surveillance error grid. J Diabetes Sci Technol. 2014;8:658-672.