VALITEST - D5.2 Guidelines on an approach to undertake horizontal proficiency testing

The 5th work package of the VALITEST project aimed at developing guidelines on a horizontal approach allowing the laboratories to undertake proficiency testing (PT) without having to participate in proficiency tests for all the tests they use. After identifying the needs and expectations of the laboratories, the acceptability of this approach has been discussed with representatives of an accreditation body. According to them, the views of experts collected previously do not constitute a sufficient level of evidence and the suitability of the approach should be demonstrated based on the analysis of proficiency testing results. Based on existing datasets it was possible to draw some conclusions but not to demonstrate the suitability of the approach. The most appropriate approach identified to limit the PT participation plan is to group the tests and evaluate the proficiency for these groups as described by the European guidance document EA-4/18. However, the identification of the groups of tests can only be done by the laboratory itself taking into account all its specific parameters. As a follow-up to the work carried out within VALITEST, a case study will be developed to accompany the EA-4/18 guidance document and facilitate the implementation of this approach by laboratories