This Excel package is designed to support internal verification of analytical precision in medical laboratories, in accordance with CLSI EP15-A3. The product includes two Excel files, implementing the EP15-A3 5 × 5 experimental design (5 days × 5 replicates/day), adapted for: two control levels (low / high), and three control levels (low / normal / high).
This Excel package is designed to support internal verification of analytical precision in medical laboratories, in accordance with CLSI EP15-A3.
The product includes two Excel files, implementing the EP15-A3 5 × 5 experimental design (5 days × 5 replicates/day), adapted for:
two control levels (low / high), and
three control levels (low / normal / high).
Together, these files allow laboratories to perform precision verification that is both efficient and robust, depending on the number of control levels available and the desired depth of verification.
Both Excel files automatically calculate repeatability and within-laboratory (total) precision and determine method acceptability using Upper Verification Limits (UVL) derived from chi-square statistics at 95% confidence, with appropriate adjustment for the number of control levels tested.
Acceptance is expressed through a clear PASS / FAIL decision by comparing observed CV% values with statistically derived UVL values, fully aligned with CLSI EP15-A3 principles. No manual calculations, statistical tables, or external tools are required.
EP15-A3 5 × 5 precision verification
Two QC levels (typically low and high)
Calculation of:
repeatability SD and CV%
within-laboratory (total) SD and CV%
UVL at 95% confidence, adjusted for two levels
PASS / FAIL decision for each precision component
Suitable for routine verification and minimal experimental burden
EP15-A3 5 × 5 precision verification
Three QC levels (low, normal, high)
Advanced statistical handling, including:
variance component estimation
effective degrees of freedom (Satterthwaite approximation)
UVL at 95% confidence, adjusted for three levels
PASS / FAIL decision for each precision component
Suitable for enhanced documentation and audit-robust verification
Fully compliant with CLSI EP15-A3
5 × 5 study design (5 days × 5 replicates/day)
Automatic calculation of:
repeatability and total imprecision
CV%
Upper Verification Limits (UVL)
Level-adjusted statistical confidence (95%)
Clear, unambiguous PASS / FAIL interpretation
No lookup tables or advanced statistical knowledge required
Print-ready format for documentation and audits
Internal method verification
Introduction of new analysers, methods, or reagent lots
Routine quality assurance activities
Support for ISO 15189–compliant laboratory documentation
This Excel package is intended for internal verification of analytical precision in accordance with CLSI EP15-A3. It does not replace extended method validation and does not constitute a clinical decision tool. Interpretation of results remains the responsibility of the laboratory professional, in accordance with the laboratory quality management system.