Proficiency testing (PT) is vital for every laboratory to assess their own performance and identify areas of testing that need some special attention. It helps to spot small changes and trends in testing that, if un-monitored, could affect the patient outcomes. PT helps to ensure that laboratory results are accurate and reliable.

Naturally, many labs have a love-hate relationship with PT. We all understand the critical importance of these tests. But, all too frequently, biennial inspections and surveys show that laboratories struggle with citations related to PT outcomes. In this two part blog, I would like to share some insights and tips to help your lab become proficient in proficiency testing by identifying the reducing the occurrence of these citations.

When adding a new analyte to your laboratory menu, be certain that subscribing to an Approved Proficiency Testing (PT) provider service is part of the process.

For Regulated Analytes, performance of Proficiency Testing is a requirement.  Providers will send five challenges for the regulated analytes at approximately equal intervals three times per year.  Non-regulated analytes are required to be challenged twice per year, either by PT or some scientifically defensible means of comparison, such as split-sample analysis.

I recommend you perform Proficiency Testing rather than split sample analysis.  All too frequently laboratories that rely on split samples fail to perform the analyses in a timely fashion.  For waived testing, I strongly urge that PT be performed to monitor successful test performance in your laboratory.

Be certain your PT procedure is complete and is understood by all testing personnel.

The PT procedure need not be elaborate and long, but it is essential that it include all the criteria listed in CLIA ’88 regulations.  (The examples are much of what follows.)

The PT specimens should be incorporated into the routine patient workload.

Be certain that your staff treat each PT sample as a patient sample while undergoing the testing process.  If the laboratory does not have a written policy to repeat a test when a given result is obtained, the PT sample cannot be repeated to “just check the result”.  However, if the laboratory has a policy to repeat patient samples with given results e.g. white count >20,000, and this policy is followed, a PT sample, treated the same as a patient may be repeated when the WBC is >20,000.

Do not delegate the performance of PT to select personnel.

If possible, all testing personnel should perform PT at some point during the year.  Understandably, in some of the larger laboratories this may not be possible.  For each testing event, the Laboratory Director and each of the testing personnel performing the testing must sign a statement attesting that the PT challenges were handled in the same manner as a patient specimen.

Do not, under any circumstances, send a PT sample to another laboratory.

This prohibition includes laboratories which may be related to your practice. Even in instances where a comparable patient sample would be sent to a reference laboratory, either for confirmation or supplementary testing, the PT sample cannot be sent to the reference laboratory.   When reporting your PT results, there will be an option on the reporting form that you should mark to indicate that a patient specimen of this type would normally be referred.    I realize this seems contradictory to our discussion about treating PT samples just as you would a patient sample, but this is a strict CLIA regulation and violations can potentially lead to the loss of a laboratory license for a year and inability of the Laboratory Director to hold that position for two years.

Ensure laboratory staff is educated on the CLIA Regulation regarding communication to other laboratories.

It is imperative that laboratory staff is aware that, when testing a PT sample, no communication can take place with any other laboratory (including other laboratories in your practice) prior to the cut-off date for submission of the PT results.  Note that this is not after the submission of results from your laboratory to the PT provider but rather after the date established by the PT provider for the submission of the results.

Submit the PT results on-time.

It is important that the laboratory submit results to the PT provider within the required time frame.  The laboratory will receive a grade of zero percent for the entire testing event if results are not submitted by the cut-off date indicated by the PT provider.

Double-check your PT reporting form.

In submitting the results of PT testing, be certain that the correct codes are entered for instrument/methodology so that appropriate peer group is used for comparison of results.


I hope you find one or more of these points helpful and of assistance in avoiding some of the pitfalls which can occur with Proficiency Testing. In part 2 of this series we will explore what you can do AFTER you’ve submitted your PT results, especially if you did not receive the results you had expected.