Proficiency testing

Evaluating how well a medical laboratory performs a particular test in comparison to another laboratory using pre-established criteria.

Why does the DAP require proficiency testing in a medical laboratory?

The DAP requires proficiency testing to protect patients and the public.

Proficiency testing is critical to evaluating the quality of test results produced by the medical laboratory. Without proficiency testing, medical laboratories might perform tests and release results without knowing they might be inaccurate. By requiring labs perform proficiency testing, the DAP enhances public safety and gives confidence to health-care providers using laboratory services in BC.

To determine if laboratory A is accurately measuring blood glucose, it requests a pre-measured sample from laboratory B, runs that sample through its systems, and compares the results. If the measurement obtained by laboratory A is the same as the measurement obtained by laboratory B, then laboratory A is performing its test correctly.

This is a simple example and, in today’s world, proficiency testing is a much more sophisticated and formalized operation, with pre-measured samples coming from commercial suppliers that specialize in providing samples and statistical analysis for PT. However, the principle is the same: by comparing results across laboratories, patients, customers and laboratories themselves can be confident in the quality of services offered.

The DAP on-site assessments of medical laboratories occur once every four years. In between these on-site assessments, the DAP requires that laboratories perform PT for all applicable tests within their scope of accreditation, usually by working with a professional, third-party proficiency testing supplier.

The DAP requires laboratories participate in a minimum of two PT testing events (challenges) per year for each test within their scope of accreditation.  

Throughout the accreditation cycle the DAP receives and reviews copies of PT reports for each laboratory. Unacceptable PT results are flagged so the DAP can monitor that laboratories are submitting a PT Investigation Response Form for DAP reportable exceptions.

The laboratory investigates unacceptable PT results under the guidance of their medical director. If the unacceptable results meet the DAP reportable exceptions criteria the laboratory sends the DAP a PT Investigation Response Form which summarizes the investigation and corrective actions taken. If the results are not reportable to the DAP, the laboratory retains the investigation records as part of their quality management system records.

In cases where the medical laboratory demonstrates ongoing, unacceptable PT performance, the matter is referred to the DAP Committee for reconsideration of that medical laboratory’s accreditation award.

Forms and resources

Resource Description File type
Laboratory Medicine Proficiency Testing Manual Describes the processes, forms, and requirements of PT in accredited laboratory medicine facilities

PDF manual

Available Proficiency Testing Providers List of accredited and non-accredited PT vendors PDF list
Reportable Measurands by Service Measurands that must be monitored by formal PT programs and are reportable to the DAP

PDF list

Proficiency Testing Investigation Response Form Form to provide a summary the investigation of PT exceptions to submit to DAP PDF form
Proficiency Testing Investigation: Sources of Error Form Checklist to collate sources of errors PDF checklist