Tools, Technologies and Training for Healthcare Laboratories

Signs of Six Sigma

A few years ago, Dr. Westgard was one of the first and only voices advocating the application of Six Sigma to healthcare processes. Times have changed. Six Sigma is starting to pop up everywhere. See where it's showing up today.

The timetable for adoption of Six Sigma Quality Management in healthcare organizations has been slower than I expected, but there are some signs of Six Sigma now (in the fall of 2002). Here are some references and resources that will keep you up to date with Six Sigma in Healthcare, stimulate your own interest, and hopefully help you gain interest from others in your workplace.

Editorial comments in Clinical Chemistry

The November issue of Clinical Chemistry has an editorial on "Striving for Perfection," written by Lucian L. Leape of the Harvard School of Public Health [1]. In discussing the results of studies on analytical errors for immunoassay tests, Dr. Leape points out that the rate of potentially serious errors in one study is 6.0% and 0.5% in another. Then makes the statement:

"Although the reported laboratory error rate of 5 incorrect results per 1000 tests seem commendable and is one-tenth that of clinical healthcare overall, it is also 10 to 100 times greater than is tolerated in almost any other industry. There is much room for improvement. We are far from a 'six sigma' level of quality."

The 0.5% error rate (or 5000 defects per million, DPM) corresponds to a sigma metric of approximately 4.05 (using the conventional conversion table for short term sigma that allows for a 1.5s shift). The benchmark for a typical business or industrial process is 4.0 sigma. The 6.0% error rate (60,000 DPM) corresponds to a 3.05 sigma process, which can be benchmarked against the value of 3.0 that is the minimum performance acceptable for a production process.

Note that these studies are dealing with analytical errors of sufficient size to cause potentially misleading test results and likely adverse clinical consequences. These errors were assigned to the non-specificity of the methods or interferences in the samples. The 0.5% error rate was observed in a study of thyroid-stimulating hormone and gonadotroping immunoassays [2]. The 6.0% error rate involved a study of 66 laboratories and 74 different analytes (21 hormones, 18 tumor markers, 8 therapeutic drugs, 5 cardiac markers, 4 proteins, 2 vitamins, 16 miscellaneous, antiviral or autoantibodies) [3].

We might expect better performance from our routine chemistry and hematology tests because of the higher levels of automation and the simpler measurement technology. Of course, we can also expect worst performance for new tests performed by emerging measurement technology.

A new book on healthcare applications

The American Society for Quality (ASQ) has just published a new book, "The Six Sigma Book for Healthcare: Improving outcomes by reducing errors" [4]. You can order this book online from Quality Press -

"Six Sigma is a management method that strives to move the organization in an orderly way from its current error rate, with the specific target being a mere 3.4 errors per million opportunities. The Six Sigma Book for Healthcare is for those manage healthcare care organizations who believe that eliminating defects and errors is good for patients, good for the community, good for the bottom line, and good for management and employees alike. While Six Sigma arose in the industrial sector, leading hospitals are now applying Six Sigma to their own operations with great success, and more applications can be expected to follow. Written for a general audience but with healthcare managers and practitioners in mind, this book provides a systematic methodology for doing root-cause analysis and rectification of you quality assurance system to the exacting standards of Six Sigma."

New ASQ courses for healthcare applications

ASQ has a special area of its website that is devoted to healthcare - see . Special training courses are available for healthcare organizations, i.e., Hospital System Failure Mode and Effects Analysis:

"This two-day FMEA course is designed to provide participants with knowledge and tools to effectively assist in the development of a FMEA as outlined in JCAHO's risk analysis requirement. As a management tool, the FMEA can reduce errors and sentinel events by prioritizing high-risk departments or components in a hospital or medical treatment facility. The course features lecture and interactive workshops to reinforce the concepts."

"This course is designed to meet the newest risk management requirements from JCAHO. The lecture and workshop is a hands-on session demonstrating the development of a system Failure Modes and Effect Analysis (FMEA). Participants will learn how a system FMEA is structured to identify which processes need improvement. Software will be used to assist students in organizing and developing a system FMEA."

While defects are counted or measured to characterize process performance on the Sigma scale, FMEA is aimed at preventing defects by identifying potential sources of problems before being encountered by patients. FMEA is an analysis tool or methodology to help you achieve Six Sigma performance.

Healthcare applications at national ASQ Six Sigma meeting

The ASQ Six Sigma Conference was held January 27-28, 2003, in Palm Springs, CA. The program included a number of presentations about Six Sigma applications in healthcare. Here are the abstracts that deal with healthcare applications.

Session A7. Reducing Healthcare-Acquired Bloodstream Infections Utilizing a Six Sigma Approach to Accelerate Progress. Teresa Garrison RN, MSN, CIC, Manager, Hospital Epidemiology, BJC Healthcare, St. Louis, MO

Do you have a better chance of getting your baggage at the airport or a healthcare-acquired infection while in the hospital? Much attention has been given to the discussion of quality and medical errors in healthcare. Yet healthcare has been slower than other industries to incorporate quality improvement into the production processes of clinical practice.

The Six Sigma approach to quality improvement accelerates development of long-lasting interventions to reduce healthcare-acquired infections. Case studies will highlight two teams' successful Six Sigma work in reducing bloodstream infections related to central venous catheters in the surgical intensive care unit (SICU) and medical intensive care unit (MICU). The model presented provides a repeatable set of steps a team can learn and follow in any healthcare setting.

Session B8. Taking Performance to a Higher Level-How Six Sigma Helped a Rural Hospital Achieve a Cultural Transformation. Greg Stock, CEO of Thibodaux Regional Medical Center, South Louisiana

Big changes don't necessarily come in big packages. This is especially true for Thibodaux Regional Medical Center, a relatively small nonprofit hospital in southern Louisiana. At Thibodaux, we're beginning the third wave of our journey to excellence-a journey that has already produced impressive results in patient satisfaction, cost savings and quality improvement. Six Sigma is one of several breakthrough strategies the hospital implemented at the beginning of this journey more than 2 years ago. This presentation will share the successes of Six Sigma at our hospital and is targeted to anyone interested in learning how Six Sigma impacts the culture of an organization.

Session C3. Improving the Patient Experience in a Healthcare Facility. Brian Jackson, Argent Global Services. Mark Nash, Argent Global Services

This session will showcase a six sigma case study from a doctor's clinic located in the southwest United States. The practice employs several general practitioners (GPs) and physician's assistants (PAs) and treats approximately 150 patients per weekday. A key organizational initiative was to improve the patient experience. The patient experience, to include customer service, was not a priority beyond the traditional healthcare definition. The organization redefined this traditional definition and created a new model for healthcare delivery through the use of the six sigma methodology.

Session C8. Acute Rehab Services Assessment. Adrienne Elberfeld, Black Belt, Operations Improvement department, Virtua Health.

In the year 2000, Virtua Health made a strategic cultural decision as an organization to implement Six Sigma to reduce the variations throughout the organization in order to better meet the needs of their customers. Three years ago, two hospital systems merged to create Virtua. The rehabilitation departments were some of the first to integrate their services throughout the organization. The opportunity to have an integrated team of physical therapists from multiple sites, nursing and case management personnel, and leadership to serve as change agents utilizing the tools of Six Sigma, combined with the use of CAP and Work-Out, was of high focus for others in the system. The effects on the daily operation of the therapists through the practical use of these tools, communicated to other departments at Virtua that change through statistical analysis held many opportunities to address the CTQs of their customers.

The Acute Rehab Services Six Sigma project was started in the third wave of projects at Virtua. It was one of first to look at an ancillary department within an acute care setting. In addressing the "Voice of the Customer", the team looked at two main Ys to measure: the percentage of physician consults completed within a 24 hour period, and the percentage of therapist time spent in direct patient care. Sub-Ys as per the sponsors of the project were to look at the employee opinion surveys, Press Ganey results, and the percentage of non-billable nursing screen conversions to billable physician consults. The sponsors scoped the project to one site, which looked at developing a model that could be implemented across the system. Potential benefits identified by the team were to improve patient care that may directly effect length of stay, while streamlining the processes to increase productivity of the therapist. Team members from several Virtua sites and various levels of expertise accomplished the collaborative assessment of best practices. This, combined with the statistical data collection of current and new procedures, gave the process owners and sponsors the opportunity to drive changes through the organization to best meet customer specifications.

And as we go to press!

If you still aren't convinced that Six Sigma is on its way, then consider today's breaking news that the "Feds may unleash Six Sigma on terrorism." See the USA Today website -

This will bring Six Sigma to even wider attention of the general public and will further highlight the issues of safety. Why not safety in healthcare?


  1. Leape LL. Striving for perfection. Clin Chem 2002;11:1871-2.
  2. Ismaill AAA, Walker PL, Barth JH, Lewandrowski KC, Jones R, Burr WA. Wrong biochemistry results: two case reports and observational study in 5310 patients on potentially misleading thyroid-stimulating hormone and gonadotropin immunoassay results. Clin Chem 2002;48:2023-9.
  3. Marks V. False-positive immunoassay results: a multicenter survey of erroneous immunoassay results from assays of 74 analytes in 10 donors from 66 laboratories in seven countries. Clin Chem 2002;48:2008-16.
  4. Barry R, Murcko A, Brubaker C. The Six Sigma Book for Healthcare: Improving Outcomes by Reducing Errors. ASQC, Milwaukee, WI, 2002, 735 pages.

James O. Westgard, PhD, is a professor of pathology and laboratory medicine at the University of Wisconsin Medical School, Madison. He also is president of Westgard QC, Inc., (Madison, Wis.) which provides tools, technology, and training for laboratory quality management.