Dear API Abby

Thank you for submitting your proficiency testing questions. API Abby is here with answers! The American Proficiency Institute (API) is pleased to share its technical expertise on all things proficiency testing. API, a global leader in proficiency testing programs, is dedicated to improving the accuracy and efficiency of clinical laboratory testing. Known for its constant innovation in the field, API offers technical expertise and checklists to help its laboratory customers become more proficient. Now let’s get to your questions!

Dear API Abby:

I’m seeking ways to enhance the performance of our laboratory. Even with a passing grade on our proficiency testing challenges, how might we use the resulting proficiency testing data to improve? 

Task Rabbit

Dear Task Rabbit:

This is a great question! I am so glad you have identified that proficiency testing is more than just a pass or fail test. Proficiency testing can help you identify problems before they turn into critical errors. By looking at your overall trend in performance you may notice that you are starting to show a bias, and that may help you identify shifts in calibration or missed maintenance before you detect an error in your controls. Similarly, looking at your trend analysis over multiple events can help you identify if you have an issue that is slowly affecting the outcome of your result.

Because proficiency testing should be run as close as possible to a patient test, proficiency testing can help to identify pre- and post-analytical errors as well. A result that seems like it may have been one random error may actually be identifying someone who is missing a critical step in the testing process.  For example, take a laboratory that reported urine susceptibility results and received a failure on a common antimicrobial drug. Upon investigation, the supervisor found that the technologist did not indicate the source when setting up susceptibility testing on their instrument-based test system. Without the source information, the system tested a drug that was inappropriate to report for a urinary tract infection. This investigation alerted the supervisor to do a chart review to ensure that patient samples did not include reports with inappropriate antibiotics. This also led to a training opportunity for the technologist. 

Dear API Abby:

I know, I know… thou shalt not share proficiency testing results!  However, without revealing who performed the test, is it permissible to discuss proficiency testing results with our laboratory team after the event?  Is there a teaching schematic we might use?

All Together Now

Dear All Together Now:

Every moment can be a teaching moment, and proficiency testing is no exception. It is important that you noted “after the event.” You should never discuss your proficiency testing results during the event, but afterwards there is much to learn.

For example, proficiency testing challenges that use virtual or paper images, such as blood cells or parasite challenges, may be shared with the laboratory team after the test event’s due date.  Ask their opinions and discuss the responses.  If there was a particularly challenging image or a source your laboratory does not view on a regular basis, this may be a great teaching moment.

Quantitative results can be just as educational. If you note that you are starting to trend above or below your peer group mean on a particular analyte, challenge your staff to do some problem solving. What is occurring that may cause your laboratory to trend lower or higher than your peers? As the team investigates, they will be learning about the analyte, the instrument, your control processes, and your procedures. These wonderful learning moments may benefit both new and seasoned technologists. 

Dear API Abby:

Does the recent court action on laboratory-developed tests (LDTs) impact proficiency testing? 

Inquiring Izzy

Dearest Izzy:

In response to the court decision, in September 2025, the Food and Drug Administration (FDA) reverted its regulatory text for laboratory-developed tests back to what was issued prior to May 2024. So, the short answer to your question is no, proficiency testing is not impacted. Accuracy and validation though proficiency testing or alternative assessments continue to be required for LDTs under CLIA regulations.

Dear API Abby:

How should my laboratory be assessing accuracy if no proficiency testing is available? Are there ways for us to request new proficiency testing programs?

An Enthusiast

Dear Enthusiast:

Kudos to you for recognizing that validating the accuracy and reliability of your assays is essential to your laboratory’s overall quality. While proficiency testing is one valuable way to document performance, it is not the only option. Alternative assessments may also be used to demonstrate accuracy and reliability, especially when proficiency testing is not required or available. To meet regulatory expectations, these assessments should be performed at least twice a year. The most commonly utilized options are split-sample analysis and exchanging samples with another laboratory. These exercises may document method comparability or linearity and verify accuracy.

In addition to basics like how to obtain samples and which test results will be compared, laboratories performing alternate assessments should consider the credentials of any other laboratories providing results, the clinically allowable difference between results, and the levels of analytes to be tested. There are also services that might simplify some decisions, like a sample exchange registry that allows laboratories to obtain split samples for analytes that are complex, or for specialty testing panels, and provides results back to each participating laboratory. In any case, your laboratory director should approve and document the plan for each alternate assessment performed.

Your feedback on what you need to maintain laboratory compliance is valued by proficiency testing providers. After all, no one understands your laboratory’s needs better than you! By communicating with your proficiency testing provider via a phone call, email, request form, chat, etc., they can conduct an evaluation and begin researching the analyte, the platforms used for testing, relevant target ranges, regulatory requirements, and possible sample types to potentially offer a program. The sooner your proficiency testing provider hears of a need, the sooner they can work to create a proficiency program for that analyte. 

Dear API Abby:

My reagent is on backorder, and I don’t know when more will come in. Do I still have to do the proficiency test, or should my patient samples take priority?

Patience Counts

Dear Patience:

Of course you want to put patients first! However, sometimes that means making hard choices, and this is one of those times. Providing the best patient care means keeping up all your usual quality measures. You wouldn’t skip your routine controls, so if you are currently testing patients, you must also perform proficiency testing as scheduled. Proficiency testing may be one of the few times you test a sample with an abnormal result, or culture a bacteria species that might show up in a patient a few months from now. It is important to know that your systems are all running as intended.

Backorders always happen at the worst times, though. If you do find yourself out of reagent when your proficiency testing is scheduled, the basics are to notify your proficiency testing provider, document the situation, and save your samples. You can usually notify your provider as part of reporting your other results, indicating which tests you cannot perform. This avoids a 0% score for failing to participate. Your documentation should include the dates of the proficiency testing event, when patient testing stopped, and a record of the supplies being on backorder. Finally, if you save your samples and test them when you have supplies again, it will help to document how you would have performed.

Here’s hoping your supplies come in soon!

Dear API Abby:

My friend who works in another laboratory said they made changes after a recent inspection and added a process we do not follow where I work. My manager said we do not need to change, that their process could be due to a different requirement. This made me wonder, if all laboratories follow CLIA, how can there be “different” requirements?

Claire N. Consistent

Dear Claire:

It does seem like the rules should be the same for everyone, right? Rest assured there is no unfairness here. Different requirements can be due to differences between laboratories, but another common reason is laboratories choosing to be accredited. Accreditation usually replaces your state CLIA inspection and can include additional requirements your laboratory agrees to meet.

There are several laboratory accreditation organizations that review CLIA compliance in addition to their own accreditation requirements. CMS ensures that these approved organizations follow CLIA requirements. Other than that, the accreditation bodies are allowed to employ their own approaches for adding value. They may add requirements designed to further improve laboratory quality, such as additional proficiency testing, staff training, or laboratory procedures. They may monitor proficiency scores differently to help prevent small issues from becoming bigger problems. They may also use different terminology or add different expertise to the teams that visit laboratories. All these differences are allowed as long as the CLIA rules, at a minimum, are followed. 

Dear API Abby:

MLO polled its readers on the following question: While reviewing proficiency test results for hemoglobin A1c, you observe your laboratory’s values are consistently lower than expected. Which of the following is the most likely source of error?

A) Problem with the most recent calibration.

B) Change in reagent manufacturer or formulation.
C) Results were not transcribed onto the result forms correctly.
D) An issue with the sample storage temperature before testing.

Which is the correct answer?

MLO Reader

Dear MLO Reader:

The answer is A, a problem with the most recent calibration is the most likely source of error.  While all of the answers are important issues to investigate, calibration should be your first check when observing lower than expected values for hemoglobin A1c. 

A majority of poll respondents (64%) answered correctly with “A.”  16% answered “B,” 2% answered “C,”  and 19% answered “D.”