EP15-A3 Precision Verification Excel – (5 × 5 Design) for 2 and 3 levels of QC

Product description

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 CLSI 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.

For proper functionality, this workbook must be used with Microsoft Excel 2010 or later.

What’s included

📄 Excel file for  2 Control Levels

• EP15-A3 5 × 5 precision verification

• Two QC levels (normal, pathologic)

• 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

📄 Excel file for 3 Control Levels

• 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

Key features (both files)

• 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

Intended use

• Internal method verification

• Introduction of new analysers, methods, or reagent lots

• Routine quality assurance activities

• Support for ISO 15189–compliant laboratory documentation

Regulatory note

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.

© Dr. Valeria Mureșan – Laboratory Medicine. All rights reserved.

This professionally developed Excel workbook is intended for laboratory verification studies based on CLSI EP15-A3 guidelines.

Any unauthorized reproduction, redistribution, modification, or commercial use is prohibited without written permission from the author.

Only designated input cells are editable. All formulas, calculations, and automated functions are protected to maintain data integrity.

Digitally protected workbook. Compatible with Microsoft Excel 2010 or later.