Sigma Metric Analysis
We recently received a set of data for a chemistry analyzer. An analysis of these numbers gives us an eye-opening glimpse of real-world performance. On some tests, there were Sigma-metrics higher than 20! And yet on one test, the Sigma metric was actually below 1.0!! See which tests were good, which ones were great, and which ones were just plain ugly.
Now that we know how to translate the manufacturer's performance claims into Six Sigma metrics, let's take a hard look at some real-world data. With a performance study supplied by a "near-patient" chemistry anlayzer, we find out just how good (and how bad) performance of tests are when they're at the POC.
A remarkable study by Lenters-Westra and Slingerland in early 2010 found that 6 out of 8 HbA1c POC methods did not meet generally accepted analytical performance standards. What happens when one of those failed methods asks for a "do-over"?
A study in the September 2009 issue of Point of Care examined three different devices that measured lipid profiles and compared them to reference methods. Using that data, we evaluate performance on a Sigma-scale and determine the implications for laboratory QC.
Continuing in our series on translating method validation studies into Six Sigma metrics, we examine a Roche Integra 400+ chemistry analyzer, with data provided by St. Joseph Hospital in Houston, Texas.