Home   Resources   QC Articles   Saving Money While Improving Quality Control

Saving Money While Improving Quality Control

By John C. Yundt-Pacheco

One of the maxims of laboratory management is the ever-pressing need to do more with less, and to cope with an ever-shrinking budget. And let’s not forget the other constant of striving to increase the quality of the clinical diagnostic services provided. Here are three key suggestions for reducing expenditures while simultaneously increasing quality.

QC Design

QC design is the process of customizing quality control practices for each analyte. Just as the human body contains differing amounts of analytes with clinical interest, so too are there a wide variety of different quality specifications for those analytes. Analytes such as sodium are tightly regulated, while analytes such as iron are not. So a quality specification for sodium might be approximately 1%, with a corresponding 20% to 30% for iron.

A lab that uses the same QC strategy for sodium and iron, will be either over-controlling iron, or under-controlling sodium. With QC design, the lab can apply different QC strategies for sodium and iron, with tighter rules or higher QC frequency for sodium, and looser rules or lower QC frequency for iron.

QC design also allows the lab to optimize its quality control resources against the quality specifications or clinical utility of its test menu. The end result is less over-controlling (resulting in savings from a reduction of false rejections) and less under-controlling (resulting in an increase of quality).

QC Lot Sequestration

QC lot sequestration is the practice of working with a QC vendor to reserve enough QC material so the lab will have a supply that will last until the material expires. Prolonging the use of a given lot number allows the lab to maximize the value of its statistical history while reducing the frequency of crossover studies.

Unfortunately, what frequently happens is that a lab’s purchasing department will only issue a 12-month purchase order. If a lab is purchasing a QC material with a 36-month shelf life, a single purchase order will not work. Without making arrangements for lot sequestration, the same lot number of material may not be available when it is time to reorder. Even if it is available, the purchasing agent may try to acquire the lot number with the longest available expiration date—forcing the lab to switch lot numbers prematurely.

Labs can save time and money by entering into a lot sequestration agreement with its QC vendor to ensure that it won’t have to change lot numbers more frequently than necessary.

The 10-Day Crossover Study

Whenever QC material lot numbers are changed, a statistical ‘crossover study’ of the new material must be conducted to determine its statistical behavior.

Traditionally, statistical studies of this nature tend to be 20-day studies where the QC materials are evaluated repeatedly over that 20-day period. Crossover studies are conducted to estimate the mean (target), and standard deviation (range) of the material. Unfortunately, a 20-day study is generally insufficient to characterize the standard deviation (SD) with high confidence and can lead to overkill for computing the mean.

An alternative approach is to use an abbreviated study for 10 days with a focus on estimating the mean of the new material. Once the mean has been computed from 10 evaluations, the lab can use the coefficient (CV) from the old material that is closest to the mean to estimate the standard deviation of the new material.

CV = 100* SD/Mean, so SD = Mean*CV / 100.

Variation is generally thought to be a characteristic of the test method, unrelated to the lot number of the QC material, except that it has a dependency on concentration. Therefore, the lab can use the CV from the old lot number to estimate the SD of the new lot number.

When the lab has 60 or more evaluations of the new material, they can be used to update the initial estimate of the new lot number SD. This approach will cut the cost of changing QC lot numbers in half.

If applied regularly, the three suggested practices of utilizing QC design, using QC lot sequestration, and engaging in 10-day crossover studies—each easily incorporated into lab protocols—can lead to statistically significant increases in quality while simultaneously benefiting the bottom line.

John C. Yundt-Pacheco is a Scientific Fellow with the Quality Systems Division At Bio-Rad.

This article was originally published by Clinical Lab Products Magazine in September, 2019.

Your Privacy Matters

Before you visit, we want to let you know we use cookies to offer you a better browsing experience. To learn more about how we use cookies, please review our Cookie Policy, accessible from the Manage Preferences link below. We would appreciate your confirmation by either accepting all cookies or by declining and managing your cookie preferences under the Manage Preferences link below.


Cookie Preferences

We use various types of cookies to enhance and personalize your browsing experience on our website. You may review the various types in the descriptions below and decide which cookie preferences you wish to enable. If you wish to decline all non-essential cookies, you may browse our site using strictly-necessary cookies. To learn more about how we use cookies, please visit our Cookie Policy.

Strictly-Necessary Cookies

These cookies are essential for our website to function properly. They either serve as the sole purpose of carrying out network transmissions or they allow you to browse and use features, such as accessing secure areas of the site. These cookies are strictly necessary because services like the shopping cart and invoicing cannot be provided without these cookies. Since these cookies are strictly necessary in order for our website to function, no consent is required to enable them. If you wish to disable these cookies, please update your settings under your browser’s preferences. If these cookies are disabled, please be aware that you will not be able to access certain features of the site like purchasing online.

Functionality Cookies

These cookies improve your browsing experience and provide useful, personalized features. They are used to remember selections that you have made such as your preferred language, region, and username. They also remember changes that you made in text sizes, fonts, and other customizable parts of the Web. Together, this information allows us to personalize features on our website in order to provide you with the best possible browsing experience. The information that these cookies collect is anonymous and cannot track your activity on other websites.

Analytics Cookies

These cookies are used to help ensure that your browsing experience is optimal. They collect anonymous data on how you use our website in order to build better, more useful pages. For instance, we can recognize and count the number of visitors, see how visitors moved around the site, and we can identify which pages returned error messages. This information enables us to enhance your experience and helps us troubleshoot any issues that prevented you from reaching the content that you needed. In order to improve the performance of our site, we use products such as WebTrends OnDemand and Google Analytics to track site usage. You can find the list of products that we use to collect information that is relevant to Analytics Cookies here:

  • Google Analytics
  • Adobe Analytics
  • SessionCam
  • ForeSee
  • WebTrends On Demand

Targeting or Advertising Cookies

These cookies are used to deliver personalized content based on your interests through third-party ad services. This allows us to improve your online experience by helping you find products that are relevant to your interests faster. They remember websites that you have visited and the information is shared with other organizations such as advertisers. These cookies are also used to limit the number of times you see an ad and help measure the effectiveness of a marketing campaign. You can find the list of products that we use to collect information that is relevant to Advertising Cookies here:

  • Marketo
  • Kenshoo
  • Doubleclick

Log In / Register

Log In / Register