Proficiency Testing and Interlaboratory Comparisons
Proficiency testing evaluates laboratory performance by comparing results on common samples.
Benefits
It can reveal:
- calibration bias
- method differences
- reporting errors
- analyst variability
- matrix effects
- reference-standard differences
Study design
A useful comparison requires homogeneous and stable samples, clear instructions, statistical analysis, and appropriate peer grouping.
Interpretation
An outlying result should trigger investigation, not automatic blame.
Frequently asked questions
Is proficiency testing the same as method transfer?
No. Proficiency testing evaluates ongoing performance across laboratories.
Can one successful round prove competence?
No. Repeated performance is more informative.
What if no formal program exists?
A controlled bilateral or multilaboratory comparison may be used.
Should laboratories know the assigned value in advance?
Usually not, because blind testing better evaluates routine performance.
Key takeaways
External comparison is a strong tool for detecting hidden bias and confirming laboratory competence over time.
References
- FDA. Data Integrity and Compliance With Drug CGMP: Questions and Answers.
- OECD Principles of Good Laboratory Practice.
- ISO/IEC 17025 overview.
TSMS Labs educational disclaimer: For laboratory research and educational purposes only. Not for human consumption. This content is not medical, clinical, or regulatory advice.