Blog Review

May 26, 2017

I started this blog 13 years ago in March 2004 – the first two articles are about six sigma, here and here. The blog entry being posted now is my 344th blog entry.

Although the blog has an eclectic range of topics, one unifying theme for many entries is specifications, how to set them and how to evaluate them.

A few years ago, I was working on a hematology analyzer, which has a multitude of reported parameters. The company was evaluating parameters with the usual means of precision studies and accuracy using regression. I asked them:

  1. a) what are the limits that, when differences from reference are contained within these limits, will ensure that no wrong medical decisions would be made based on the reported result (resulting in patient harm) and
  2. b) what are the (wider) limits that, when differences from reference are contained within these limits, will ensure that no wrong medical decisions would be made based on the reported result (resulting in severe patient harm)

This was a way of asking for an error grid for each parameter. I believe, then and now, that constructing an error grid is the best way to set specifications for any assay.

As an example about the importance of specifications there was a case for which I was an expert witness whereby the lab had produced an incorrect result that led to patent harm. The lab’s defense was that they had followed all procedures. Thus, as long as they as followed procedures, they were not to blame. But procedures, which contain specifications, are not always adequate. As an example, remember the CMS program “equivalent quality control”?


Transferring older posts

May 15, 2017

I have started the process of transferring older posts, which were in my now defunct website, to this blog. It will take a little while and additionally it will take some time for the search engines to catch up.


I’ve retired – sort of

May 11, 2017

As of the end of 2016, I stopped consulting. I still follow lab medicine topics that interest me, and will still publish both papers in journals and entries on my blog.

I ended my website KrouwerConsulting.com – it doesn’t work anymore – and I realize that some of my earlier blog entries can’t be accessed because they were on KrouwerConsulting.com (written before I started my current blog). I will fix this and transfer all of these entries to my current blog, as soon as I figure it out!

I want to thank all of my clients. Their problems kept me thinking and I enjoyed both the technical tasks and meeting people to discuss a variety of issues.