Basic instructions for participants in a proficiency testing scheme

Significance of Proficiency Testing

Proficiency testing (PT) is a cornerstone of laboratory quality management, enabling facilities to benchmark their analytical performance against peers and international standards. Accurate participation in PT schemes builds confidence in data reliability, supports accreditation requirements, and drives continuous improvement in routine testing.

Objectives and Scope of the Guide

This guide presents a structured checklist for laboratories preparing for and engaging in a proficiency testing scheme. It covers key phases from initial planning through receipt of materials, measurement execution, result reporting, evaluation, and corrective follow-up to ensure compliant and effective participation.

Methodology and Procedural Steps

The recommended workflow comprises six sequential stages:

1. Preparation before participation
   • Confirm provider contact, billing and shipping details
   • Establish or review internal procedures for result review, corrective actions, periodic performance review, and report storage
2. Receipt of PT items
   • Inspect package integrity and request replacements for compromised items
   • Review handling, storage, and preparation instructions
   • Register and label materials according to laboratory protocols
   • Store items under specified conditions
3. Measurement execution
   • Follow provider instructions and treat PT samples like routine tests
   • Meet any deadline requirements
4. Reporting of results
   • Allow adequate time and submit required information in the correct format (units, significant figures)
   • Verify data entries and confirm submission completion
5. Review of PT reports
   • Check report accuracy and discuss comments on performance
   • Document and store reports per internal procedures
6. Follow-up actions
   • Investigate any poor performance per the quality system
   • Assess impact on customer data and implement corrective measures
   • Use surplus PT samples for re-assessment where feasible
   • Monitor performance trends over time

Main Outcomes and Discussion

By applying this checklist, laboratories can minimize common errors such as improper sample handling, reporting mistakes, and delayed submissions. Systematic documentation of each step enhances transparency and supports accreditation audits. Reflecting on evaluation feedback fosters targeted improvements in analytical methods and quality systems.

Benefits and Practical Applications

Regular PT participation helps laboratories:

• Demonstrate comparability and traceability of measurement results
• Identify training needs and equipment calibration issues
• Enhance customer confidence and regulatory compliance
• Streamline corrective and preventive action processes

Future Trends and Applications

Emerging digital platforms promise more efficient enrollment, data submission, and interactive result review. Integration of statistical analytics and machine learning may offer deeper insights into performance patterns. Remote or on-demand PT schemes could increase accessibility for smaller or distributed laboratories.

Conclusion

Adherence to a structured proficiency testing protocol is vital for sustaining high analytical standards. This guide equips laboratories with practical steps to ensure accurate participation, robust result evaluation, and continual quality enhancement.

References

• Brookman B and Mann I, editors. Eurachem Guide: Selection, Use and Interpretation of Proficiency Testing (3rd ed., 2021).
• Eurachem. Selecting the right proficiency testing scheme for my laboratory (leaflet, Ed. 2, 2022).
• Eurachem. Proficiency testing – How much, and how often? (leaflet, Ed. 2, 2022).
• Eurachem. How to investigate poor performance in proficiency testing (leaflet, Ed. 2, 2022).
• Eurachem. Use of surplus proficiency test items (leaflet, Ed. 2, 2022).