Tools, Technologies and Training for Healthcare Laboratories

Westgard Sigma Verification of Performance Program

Do you know the performance of your laboratory methods? Can you prove it? Do you want help? The Westgard Sigma VP program may be right for you.

Sigma Verification of Performance (Sigma VP) Program

James O. Westgard, PhD and Sten Westgard, MS

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Westgard Sigma Verification of Performance at Innovative Diagnostics, Singapore

"Everyone complains about the weather, but nobody does anything about it." This classic remark, made first by Charles Dudley Warner, and then later attributed to people as diverse as Mark Twain and Yogi Berra, applies to a lot of the academic discussions about the quality of laboratory methods.

Another relevant saying, one that perhaps applies more directly to the Westgard website, is the Hagar the Horrible cartoon where someone scolds Hagar, "It's better to light a candle than curse the darkness." To which Hagar replies, "But I enjoy cursing the darkness."

At Westgard Web, we have certainly written a lot about the quality of testing methods. We have even "cursed" in our own way some of the methods out there that aren't very good. And we've haven't held back our opinions about the shortcomings of different regulatory policies and proposed QC schemes.

But it's time we try and do something about it.

With that in mind, we're introducing a new initiative, the Westgard Sigma Verification of Performance program. This is an opportunity to highlight laboratories that are doing the right thing: they have the right methods, they have the right staff and training, they have the right QC implementation, and they have the right test results. For laboratories that are seeking new ways to validate the performance of their instruments, here is a chance to show the difference between a good laboratory and a merely compliant one.

We should be clear upfront what this program is not. This is not an accreditation program, nor does it replace any required regulatory compliance. It is not as broad as ISO 15189, nor as checklist-oriented as CAP. But where a lot of accreditation and regulatory systems leave off, the Sigma VP program steps in. While accreditation programs are satisfied if you have a written policy for QC and can prove that you are implementing that QC, the Sigma VP program will ask and demand that you do the Right QC. Where laboratory inspectors will not challenge the quality of the instrument your laboratory is using, the Sigma VP program will require that you provide quantitative evidence that the instrument is performing not just adequately, but at a 4-Sigma level or higher. Most other programs advise that you set quality goals without telling you how to set those goals. Westgard QC will provide you with a set of total allowable errors for use in benchmarking the quality of your tests.

In other words, this program is not positioned at the high, abstract altitude of "Quality System" - it's much more focused on the bottom line of your method's true Quality Performance. That said, the two concepts work hand in hand. You can't really have a Quality System without actually having appropriate method performance. And if you want to get the right method performance, having a Quality System is going to help you accomplish that much more easily.

A brief outline of the process:

  1. Application submission
  2. Optional pre-assessment
  3. GAP Analysis (through document review)
  4. Initial Assessment
  5. Corrective Actions (if needed)
  6. Final Assessment and Decision on Granting of Verification.

The Sigma Verification will require your data and the use of Sigma-metric tools:

  1. Designate the necessary Quality Managers to learn and implement Six Sigma tools
  2. Adopt a standard set of quality goals, provided by Westgard QC
  3. Evaluate analytical performance
  4. Assess quality on the Sigma-scale
  5. Redesign QC based on the Sigma-metrics
  6. Apply and Request a review of laboratory data
  7. Implement and integrate Sigma-metric policies and procedures into the laboratory's Quality Manual
  8. Establish a continuous quality improvement plan to assess and update method Sigma-metrics

An important distinction is that this is a Verification program, not a certification, not an accreditation, not an award. This is not going to reward past behavior - it's about verifying and proving that your current method performance is appropriate for patient care, and assuring that a system and staff are in place to continuously assure this level of quality. As such, the verification duration is only a year. Laboratories that successfully achieve verification of their Sigma performance will be required to continuously improve, to add more tests to their list of verified methods, to prove that level of performance every year. There will also be a random audit during the year to provide an additional check of the performance.

Ultimately, Westgard QC wants to find partner laboratories that are dedicated to high performance and that are willing to invest in their staff and their methods in order to achieve that performance. As we said, this program is not going to be an award for past performance. We're trying to establish collaborations that will extend into the future.

Laboratories that have already succeeded in this verification program include:

If your laboratory wants to prove their method quality in a very data-driven way, to stand out from the pack of compliance-minded, lowest common denominator quality competition, to work on real performance, not just going through the motions of quality, the Sigma Verification of Performance program is for you.

If your laboratory is interested, we invite you to contact Westgard QC at This email address is being protected from spambots. You need JavaScript enabled to view it.