User Verification of Lab Precision (CLSI EP15-A3)

📌 Purpose of the tool

This Excel template has been developed for medical laboratories that need to perform user verification of precision for analytical methods, in compliance with the Clinical and Laboratory Standards Institute (CLSI) EP15-A3 guideline.
It provides a structured and automated solution for evaluating repeatability (within-run precision) and reproducibility (between-day precision) using experimental data collected over 5 consecutive days × 5 replicates per day, across up to three different control levels.

This verification step is essential for laboratories working under ISO 15189:2022 accreditation, ensuring that the analytical methods perform within the manufacturer’s claimed precision and meet international quality requirements.

🔬 Experimental design

Number of days: 5

Replicates per day: 5

Total measurements per control level: 25

Control levels: 2 or 3 levels ( you get 2 excel files)

📊 What this Excel calculates automatically

Repeatability (within-run precision)

Standard deviation (SD) of replicate results for each day

Coefficient of variation (CV%) within each run

Overall intra-run CV%

Reproducibility (between-day precision)

Variation of daily means across the 5 days

Total variance including within-run and between-day components

Overall total CV%

Comparison against manufacturer’s claims

User enters the claimed intra-run CV% and total CV% (from manufacturer’s datasheet)

The program automatically checks whether the laboratory results are within the acceptance criteria

Final decision

The tool provides a clear verdict: VERIFIED / NOT VERIFIED for both intra-run and total precision, in accordance with CLSI EP15-A3 acceptance rules.

📑 Structure of the file

Level 1 – Data entry and calculations for the first control level

Level 2 – Data entry and calculations for the second control level

Level 3 – Data entry and calculations for the third control level

Instructions – Step-by-step guide on how to use the template correctly

Copyright – Terms of use and license

🌟 Why this tool is valuable for your lab

✔ Ensures compliance with CLSI EP15-A3 requirements
✔ Supports ISO 15189:2022 accreditation by documenting method precision
✔ Provides ready-to-use automated calculations (no manual statistics required)
✔ Saves significant time in validation and verification studies
✔ Produces professional documentation suitable for audits and quality management systems
✔ User-friendly format – only basic Excel knowledge is needed

📌 Who should use this file

Medical laboratories validating new analytical methods

Quality managers and laboratory supervisors

Professionals preparing for ISO 15189 accreditation or re-accreditation

Educators and students in laboratory medicine learning method validation techniques

📚 References

CLSI EP15-A3: User Verification of Precision and Estimation of Bias; Approved Guideline – Third Edition

ISO 15189:2022 – Medical laboratories – Requirements for quality and competence

✨ Format

2 files Excel template (.xlsx)

Language: English

Ready for immediate download and use

Author: Dr. Valeria Mureșan, Medical Doctor in Laboratory Medicine