Risk analysis approach for PT participation

The standards ISO/IEC 17025 [1] and ISO 15189 [2] both require laboratories to monitor their performance by comparison with results of other laboratories. But to what extent do laboratories have to participate. At what level and which frequency should a laboratory participate in PT schemes? To facilitate this question, a risk analysis approach should be applied by the laboratory. The EA (European co-operation for Accreditation) advisory document EA-4/18 (Guidance on the level and frequency of proficiency testing participation) [3] first published in June 2010 was revised in 2021 to include as one of the objectives, the concept of the risk analysis approach for PT participation. Risk analysis can be a nebulous concept so how can it be applied to PT participation? What criteria are important to take into consideration, can it be standardized, how do you train assessors to assess the suitability of a participation in PT strategy based on a risk analysis approach? To obtain feedback to such questions above, a survey was prepared and sent out to the EA accreditation bodies (Abs) to understand how this risk analysis approach is being implemented in their jurisdictions. In this survey, the following questions were posed:

• Are common risk-based principles used?

• What training is given to the assessors to ensure harmonization?

• What are the mains risks that are considered?

• At what frequency is the suitability of the laboratory’s risk-based approach (strategy) assessed?