Chapter 5 Choosing a Quality Control Product

Summary

Chapter 5 emphasizes the importance of selecting quality control products for laboratories, cautioning against the lure of low-cost options that may have limited shelf life and inadequate analyte levels. It advises understanding daily control usage to avoid waste and warns against misleading 'box pricing'. Laboratories should consider the diagnostic utility of products for their test menu, the reliability of results, and the value of additional services like interlaboratory comparison programs. The chapter concludes by stressing the need for accurate, reliable quality control to protect both the lab's reputation and patient health.

Takeaways

• 🧪 Laboratories have various quality control products available, but choosing the right one requires careful consideration.
• 💰 Opting for cheaper quality control products can lead to limitations such as a shorter shelf life and potential waste.
• ⚠️ Some quality control products are not similar enough to patient specimens, which can cause issues with certain test systems.
• 📦 'Box pricing' can be misleading; it's important to ask for quotes on a per mL basis rather than just the box price.
• ⏳ Laboratories should match the quality control product's shelf life with their daily usage to avoid wasting resources.
• 📉 Purchasing quality control products that don't align with the lab's diagnostic criteria can lead to inaccurate test results.
• 🔍 Selecting a quality control product that offers trilevel diagnostic utility is crucial for accurate lab results across different analytes.
• 🏥 Inaccurate lab results can damage a laboratory's reputation and, more importantly, harm patients.
• 📊 Participating in an Interlaboratory Quality Control Comparison Program is recommended to regularly verify the reliability of lab work.
• 🌍 The value of additional services provided by the quality control product manufacturer, such as interlaboratory comparison programs, should be considered when making purchasing decisions.

Q & A

What is the primary consideration when choosing a quality control product for a laboratory?

The primary consideration is to choose a product that matches the laboratory's needs in terms of stability, similarity to patient specimens, and analyte levels at medically relevant decision points.

Why might a laboratory face unnecessary waste with cheaper quality control products?

Laboratories might face unnecessary waste because cheaper products often have a shorter shelf life, which can lead to material not being used before it expires if the laboratory's usage rate is low.

How can 'box pricing' mislead laboratory administrators when purchasing quality control products?

Box pricing can mislead by quoting a price per box without specifying the price per mL, which may seem cheaper but can actually be more expensive when the volume per box is considered.

What is the importance of the shelf life of a quality control product in relation to a laboratory's usage rate?

The shelf life should match or exceed the laboratory's normal usage rate to prevent waste. If the shelf life is shorter than the time needed to use the product, it can result in significant waste and increased cost per mL.

Why is it crucial for quality control products to have analytes at medically relevant decision levels?

Having analytes at medically relevant decision levels ensures that the quality control product can adequately challenge the test system and provide accurate control for the full range of patient results.

What is the significance of a quality control product being similar to patient specimens?

Quality control products need to interact with the test system in a manner similar to patient specimens to ensure accurate and reliable test results.

How can a laboratory assess the value of a quality control product beyond its price?

A laboratory should assess the product's diagnostic utility across the entire test menu, the vendor's support services, the availability of interlaboratory comparison programs, and the reliability and ISO certification of the vendor.

What are the potential consequences of selecting a quality control product that does not adequately control low or high levels of analytes?

Selecting a product that does not adequately control analyte levels can lead to incorrect laboratory results, which can damage the laboratory's reputation and, more importantly, harm patients.

Why is participation in an Interlaboratory Quality Control Comparison Program recommended for laboratories?

Participation in such programs allows laboratories to verify the reliability of their work by comparing their results with other laboratories using the same instrument and method, thus improving overall quality control.

What additional services should a quality control purchaser consider when evaluating a vendor?

The purchaser should consider whether the vendor provides an interlaboratory comparison program, professional staffing for technical advice, comparative statistical reports, QC software that can import data, educational support, and ISO certification.

Outlines

00:00

🔬 Choosing the Right Quality Control Product

Chapter 5 emphasizes the importance of selecting a quality control product that fits the laboratory's needs. It warns against the pitfalls of choosing the cheapest option, which may lead to issues like short shelf life and increased waste. The chapter also discusses the importance of product similarity to patient specimens to ensure accurate test system interaction. The concept of 'box pricing' is introduced as a misleading practice, and the necessity of matching the shelf life of quality control products with the laboratory's usage rate is highlighted. The summary also touches on the need for quality control products to have all analytes at medically relevant levels and the value of interlaboratory comparison programs.

05:06

💡 Importance of Diagnostic Utility in Quality Control

Paragraph 2 delves into the challenges of finding a perfect quality control product and the need to assess the entire test menu when choosing a vendor. It stresses the risk of reporting incorrect results when a product does not provide adequate diagnostic utility across the test menu. The paragraph also underscores the significance of interlaboratory comparison programs in verifying the reliability of laboratory work and the value of additional services provided by manufacturers, such as technical advice, comparative statistical reports, QC software, and educational support. It concludes by urging laboratories to select quality control products that offer the best trilevel diagnostic utility to safeguard both reputation and patient health.

10:12

🌐 Resources for Laboratory QC Needs

The final paragraph serves as a call to action, directing laboratories to www.qcnet.com for all their quality control needs. It succinctly reiterates the key points from the previous paragraphs, reminding the reader of the importance of choosing quality control products that provide comprehensive diagnostic utility and the potential consequences of selecting inferior products. The paragraph ends with a clear directive for laboratories to seek out resources that can help them make informed decisions about their quality control products.

Keywords

💡Quality Control Product

A quality control product refers to materials used in laboratories to monitor and ensure the accuracy and precision of tests and analyses. In the script, it is emphasized that choosing the right quality control product is crucial for laboratories to maintain the integrity of their results. The importance of not compromising on quality for the sake of cost is highlighted, as cheaper alternatives may have limitations like short shelf life or inadequate analyte levels.

💡Shelf Life

Shelf life in the context of the script refers to the period during which a quality control product remains stable and effective after opening. It is a critical factor for laboratories with varying usage rates, as a product with a short shelf life can lead to waste if not fully utilized within the given time frame. The script warns against purchasing products with insufficient shelf life that do not match the laboratory's usage patterns.

💡Patient Specimens

Patient specimens include biological samples such as serum, urine, spinal fluid, or plasma collected from patients for diagnostic testing. The script mentions that quality control products should be similar to these specimens to ensure they interact with test systems in a manner that accurately reflects patient sample behavior, which is vital for reliable test outcomes.

💡Analytes

Analytes are the substances or chemicals being measured in a laboratory test. The script discusses the importance of quality control products containing all relevant analytes at medically significant decision levels. This ensures that the quality control process is comprehensive and can effectively monitor the performance of the laboratory's tests.

💡Box Pricing

Box pricing is a pricing strategy mentioned in the script where the cost of a quality control product is quoted per box rather than per unit volume (e.g., per milliliter). This practice can be misleading as it may not reflect the true cost per volume used by the laboratory. The script advises laboratories to always request pricing on a per milliliter basis to avoid overpaying.

💡Trilevel Quality Control

Trilevel quality control refers to a system with three distinct levels of control samples used to evaluate the performance of laboratory tests across a range of values. The script uses this term to illustrate the need for quality control products that can challenge the test system across low, normal, and high levels, ensuring accurate diagnostic utility.

💡Interlaboratory Comparison Program

An interlaboratory comparison program is a service that allows laboratories to compare their results with those of other laboratories using the same methods. The script recommends participation in such programs to verify the reliability of a laboratory's work and to ensure that the quality control measures are effective. It provides an example of the Unity™ Interlaboratory Program from Bio-Rad.

💡ISO Certification

ISO certification is an international standard that ensures a company's products and services meet quality and safety standards. In the script, it is mentioned as a factor to consider when evaluating a quality control product vendor, indicating that a vendor with ISO certification is more likely to provide reliable and high-quality products.

💡Linearity

Linearity in the context of laboratory testing refers to the ability of a test to provide accurate and precise results over a wide range of concentrations. The script discusses how quality control products should adequately challenge the upper limit of linearity of the instrument to ensure that the test system performs well across its entire measurement range.

💡Diagnostic Utility

Diagnostic utility refers to the effectiveness of a quality control product in supporting the diagnostic process by providing accurate control levels that reflect real patient samples. The script emphasizes the importance of selecting quality control products with the best trilevel diagnostic utility to ensure that laboratory tests are reliable and clinically meaningful.

💡Laboratory Information System (LIS)

A Laboratory Information System (LIS) is a software system used by laboratories to manage and process test results and other data. The script mentions the importance of QC software packages that can import data from instruments or LIS systems, indicating that integration with these systems is a valuable feature for streamlining the quality control process.

Highlights

Choosing the right quality control product is crucial for laboratories and requires careful consideration.

Inexpensive quality control products may have limitations such as short shelf life after opening.

Products not similar to patient specimens can cause issues with test systems.

Some quality control products lack medically relevant decision levels for all analytes.

Laboratory administrators can be misled by 'box pricing', which may not reflect the true cost per mL.

It's important to know the approximate volume of control used daily to avoid waste.

Quality control shelf life should match or exceed the laboratory's normal usage rate.

Box pricing can be misleading; always ask for quotes on a per mL basis.

Laboratories should compare relevant clinical levels to those provided in the quality control product.

Trilevel quality control should meet diagnostic criteria and challenge the upper limit of linearity.

Cheaper products may not provide adequate control across the entire test menu.

Inadequate quality control can lead to incorrect laboratory results, damaging reputation and potentially harming patients.

Laboratories should select quality control products that provide the best trilevel diagnostic utility.

Participation in an Interlaboratory Quality Control Comparison Program is highly recommended.

Unity™ Interlaboratory Program from Bio-Rad is one such program that benefits over 15,000 laboratories worldwide.

When evaluating a quality control product, consider the value of services provided by the manufacturer.

Manufacturers should provide interlaboratory comparison programs, professional staff, and comparative statistical reports.

The quality control purchaser should evaluate the reliability, ISO certification, and value of the product and services.

For all your laboratory QC needs, consider visiting www.qcnet.com for more information.

Transcripts

Welcome to Chapter 5: Choosing a Quality Control Product. Many different quality control products

are available for laboratories. Choosing the right quality control product requires careful

consideration.

Sometimes laboratory decision makers yield to the temptation of purchasing the most inexpensive

product. Unfortunately, the cheaper alternative often exhibits significant limitations such

as a short shelf life after opening. A reduced shelf life can result in unnecessary waste

if the laboratory cannot use all the material. Other products are not sufficiently similar

to patient specimens (serum urine, spinal fluid, or plasma). This can cause some problems

with certain test systems because these products do not interact with the test system in the

same manner as a patient sample. Some inexpensive quality control products don’t have all

analytes at medically relevant decision levels. In some cases, laboratory administrators are

misled by “box” pricing. This “Box Pricing” topic is described more thoroughly in this

module.

When purchasing a quality control product, it is necessary to know the approximate volume

of control to be used each day. For example, general chemistry control products are usually

sold in 10 mL vials. Laboratories that use 10 mL or more per day, generally are not concerned

with stability. But for those laboratories that use a low volume of control (1 mL/day

for example), shelf life becomes an important issue.

Your quality control shelf life should match or exceed the laboratory’s normal usage

rate or money will be wasted.

For example, a laboratory that purchases a quality control product that offers only a

5 day stability, when their usage rate would require 10 days to fully use the product,

will waste 50% of the product.

Consequently, if the laboratory paid $0.18/mL for the product, their actual cost based on

usage is $0.36/mL. A better purchase choice would have been a more expensive quality control

product ($0.28/mL) that offered a 10 day shelf life stability for all analytes.

Box pricing is a misleading quoting practice that many laboratories fall into at one time

or another. Assume a laboratory is negotiating prices with two vendors for an expensive quality

control product. One vendor offers the product at $8.00 per mL or $144 per box, and the other

vendor offers the product at $120 per box without quoting a per mL price. The first

vendor provides 18 mL for $144, while the second vendor only provides 12 mL for $120.

The product cost per mL from the second vendor is equal to $10 per mL, or $2 per mL more

than the box quoted at $144. Always ask for quality control product quotes on a per mL

basis and not the box price.

This aspect of quality control products is important. It requires the laboratory to compare

the relevant clinical levels for each test to those provided in the quality control product.

For example, the laboratory objective is to purchase a trilevel (three level) quality

control that will allow the lab to “control” (evaluate) the method curve for low TSHs,

normal TSHs, and abnormal high. A quality control vendor offers an immunoassay control

with three levels. This product meets the laboratory’s diagnostic criteria. It contains

three distinct levels at the decision limits used by the laboratory and adequately challenges

the upper limit of linearity of the instrument. A second vendor also offers a trilevel product

for a reduced price. In this case, the cheaper product does not “control” low TSH because

the level is higher than the laboratory decision limit. Furthermore, it does not provide adequate

control on the high end of the curve because the level for the high control is too near

the instrument linearity limit and may often exceed the limit. The price is lower but the

product provides less or no value.

CAUTION: It is often impossible to find a perfect quality control product for every

instrument, kit or method available. When deciding on a quality control vendor, assess

the entire test menu of the instrument or department. For example, the immunoassay instrument

used in the laboratory has a test menu that includes about 50 different hormones and therapeutic

drugs. One quality control product which may be more expensive provides trilevel diagnostic

utility for 45 analytes. A less expensive product may provide true trilevel utility

for only 30 of the 50 analytes or 60% of the test menu. Whenever a test result cannot be

adequately verified, the laboratory runs the risk of reporting a result which may be incorrect.

Incorrect laboratory results can damage laboratory reputation, but more importantly they may

harm patients. Whenever possible, a laboratory should select the quality control product

that provides the best trilevel diagnostic utility.

Participation in an Interlaboratory Quality Control Comparison Program is highly recommended.

Without such programs the laboratory becomes a statistical island and has no means to regularly

verify the reliability of its work. One of the easiest methods to assess reliability

and imprecision is to compare the within-laboratory method means and standard deviations to other

laboratories using the same instrument and method (peer group). Over 15,000 laboratories

worldwide benefit from their participation in the Unity™ Interlaboratory. Program from

Bio-Rad. Find out more at www.QCNet.com.

While pricing and the appropriateness of analyte concentrations is important, the quality control

product purchase decision should also take into consideration the value of other services

provided by the manufacturer. The quality control purchaser should have the following

in mind when evaluating a quality control product. Does the manufacturer provide an

interlaboratory comparison program? Is the interlaboratory program professionally staffed

in order to provide the optimal technical advice or help? How many laboratories use

the program? What kind of comparative statistical reports are provided and are they easily readable

and understandable? Are comparative reports returned quickly? Does the manufacturer provide

a QC software package? Can the software package import QC data from instruments or LIS systems?

Does the vendor provide any educational support? Are the product and services reliable? Is

the vendor ISO certified? Does the vendor provide a high quality product at a good value?

We have reached the end of this module. Let’s review some basic points. Sometimes laboratory

decision makers yield to the temptation of purchasing the most inexpensive product. Often

cheaper products exhibit significant limitations. A reduced shelf life can result in unnecessary

waste. Some products are not sufficiently similar to patient specimens (serum urine,

spinal fluid, or plasma). Box pricing is a misleading quoting practice that many laboratories

fall into at one time or another. Always ask for quality control product quotes on a per

mL basis and not the box price. Some inexpensive quality control products don’t have all

analytes at medically relevant decision levels.

When deciding on a quality control vendor, assess the entire test menu of the instrument

or department. Whenever a test result cannot be adequately verified, the laboratory runs

the risk of reporting a result which may be incorrect. Incorrect laboratory results can

damage laboratory reputation, but more importantly they may harm patients. Whenever possible,

a laboratory should select the quality control product that provides the best trilevel diagnostic

utility.

For all your laboratory QC needs go to www.qcnet.com.