A dubious six sigma claim

In the first part of these Six Sigma articles, it was noted that Six Sigma is a collection of quality tools and procedures.

Recently, there was a interference problem in BD Vacutainer test tubes that led to significant biases for a variety of immunoassays affecting a huge number of patients, and which led to retesting (1-2).

The problem was detected by an endocrinologist at NIH and initially investigated by clinical chemists at NIH.

What was striking was the following quote from a vice president of quality at BD Diagnostics Preanalytical Systems (1):

Through the application of Six Sigma methods, BD scientists and engineers have been able to identify an interference between a constituent of our product an a limited number of assays

The most beneficial use of Six Sigma is to prevent problems, for example through tools such as FMEA (Failure Mode and Effects Analysis). Thus, one could call this a failure to effectively use Six Sigma. I’m sure that BD scientists studied the problem, developed corrective actions, and looked at ways to preventing this type of problem in the future. This too is Six Sigma but hardly qualifies as a Six Sigma success as implied in the quote in light of the failure prevention.

  1. Parham S. Test tub interference shows ‘chink in armor’ CAP Today 2005;19:1, 68, 70, 72, available on line at http://www.cap.org/apps/docs/cap_today/feature_stories/0105Tubes.html
  2. Raffick A.R. Bowen, Yung Chan, Joshua Cohen, Nadja N. Rehak, Glen L. Hortin, Gyorgy Csako, and Alan T. Remaley Effect of Blood Collection Tubes on Total Triiodothyronine and Other Laboratory Assays doi:10.1373/clinchem.2004.043349 available at http://www.clinchem.org/papbyrecent.shtml

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