Pop Quiz: If labs want to reach quality, do they need MAPS?

Posted by Sten Westgard, MS

In a recent issue of CCLM, an interesting opinion paper reported on a pilot study of the quality of UK laboratories.

Given 5,812 QC data points on 5 different platforms in 9 different laboratories measured over 6 months, and a quality goal of 7.0%  how many of those laboratories do you think achieved 5-Sigma quality?

• 100%
• 75%
• 50%
• 25%
• less than 25%

The answer, after the jump...

The answer, alas, is that less than 1 in 4 labs can achieve 5 Sigma or higher for HbA1c, given a quality requirement currently supported by NGSP/CAP (next year, by the way, that goal will tighten down to 6%).

This finding is from the following study:

Can current analytical quality performance of UK clinical laboratories support evidence-based guidelines for diabetes and ischaemic heart disease? - A pilot study and a proposal.  Nuthar jassam, John Yundt-Pacheco, Rob Jansen, Annette Thomas, and Julian H. Barth, Clin Chem Lab Med. 2013 Aug 1;51(8):1579-84.

MAPS is a new effort to generate Minimum Allowable Performance Specifications for laboratory testing. The study also noted the minimum allowable CV, as well as how many labs were able to achieve that goal, and also, what CV the median lab was achieving.

For HbA1c, MAPS offered two goals, 6.3% and 7.0% (the latter goal being defined by the NGSP program, which CAP supports in its PT program). The allowable CV based on that is 2.3 to 2.5%, and more than half of the laboratories were able to achieve that. The median CV of labs was 1.9%.

When you use 2.5% and 1.9% as your measurements for imprecision, given a goal of 7.0%, you quickly see that the Sigma-metric of median and majority of labs is right around 2.8 to 3.7 (and that, only if we assume zero bias). Performance in that range means a lot of defective test results are being generated, and even if labs are using robust "Westgard Rules" they aren't going to be able to catch them in the first run all the time. This is what a majority of labs are producing right now.

Part of the proposal recognizes that labs alone can't improve quality - the manufacturers need to make improvements in the design and performance of the methods: "Collective and cooperative efforts should be made by the EQA schemes, the diagnostic industry and the MAPS group to set graded quality specifications that are tightened over time and with improvements in technology."

Better methods. Better QC. Better quality. That's what we need.