SMILE

Johns Hopkins University

Baltimore, MD USA

Author:
Validation Committee / Document Number: / Equ35-C-04
Effective (or Post) Date: / 18 June 2009
Review History / Date of last review: / 11 August 2010
Reviewed by: / Heidi Hanes
SMILE Comments: This document is provided as an example only. It must be revised to accurately reflect your lab’s specific processes and/or specific protocol requirements. Users are directed to countercheck facts when considering their use in other applications. If you have any questions contact SMILE.

Precision Requirements-Coagulation

Precision Requirements-Coagulation / Document Number / Equ35-C-04
Effective Date / 18 June 2009
Subject
Guidelines for precision testing for a coagulation method / Page / 1 of 1
Supercedes / New
Review History / Date of last review: / 18 June 2009
Reviewed by: / Penny Stevens
Revision History / Version # [0.0] / Revision Date [dd/mm/yy] / Description (notes)

SMILE Coagulation Precision Requirements

PRECISION is reproducibility - the agreement of the measurements of replicate runs of the same sample. Replication experiments are performed to estimate the imprecision or random error of the analytical method.

I.  Short -Term (Within Run/Day)

A.  Sample:

1.  Two levels (Low / High or Normal / Abnormal)

2.  Patient or quality control

B.  Testing: Run each sample 20 times on the same run, if possible, or at a minimum within the same day.

C.  Acceptability criteria:

1.  Calculate the coefficient of variation (CV) for each level using 20 data points.

2.  Compare to manufacturer’s stated precision claims found in the package insert.

3.  If manufacturer’s precision cannot be met, it is acceptable to attain precision that is <25% of SMILE criteria for total error. Refer to the SMILE Precision Requirements Appendix 1 SMILE Coagulation TE Table.

4.  If Short -Term precision is unacceptable, consult instrument manufacturer for assistance.

II.  Long-Term (Between Day)

A.  Sample:

1.  Two levels (Low/High or Normal/Abnormal)

2.  Patient or control serum. A lab may already have this data on hand from their daily QC runs.

B.  Testing: Run each sample two times per day for 10 days for a minimum of 20 total data points for each level of material used.

C.  Acceptability criteria:

1.  Calculate the CV for each level using 20 data points

2.  Compare to manufacturer’s stated precision claims found in the package insert.

3.  If manufacturer’s precision cannot be met, it is acceptable to attain precision that is <33% of SMILE criteria for total error. Refer to the SMILE Performance Criteria for DAIDS Analytes, Appendix 1.

4.  If Long-Term precision is unacceptable, consult instrument manufacturer for assistance.

III.  References

A.  GCLP Workshop and Workbook18-20 May 2008, page 16

B.  E. Piwowar-Manning, et. al., HIV Prevention Trials Network Microbicide Trials Network Laboratory Manual, Version 1.0, Release Date: 15 November 2006

C.  Clinical and Laboratory Standards Institute (CLSI). User Verification of Performance for Precision and Trueness: Approved Guideline-Second Edition. CLSI document EP15-A2 (ISBN 1-56238-574-7). Clinical and Laboratory Standards Institutes, 940 West Valley Road, Suite 100, Wayne, Pennsylvania 19098-1898 USA, 2005.

D.  NCCLS. (Currently CLSI) Evaluation of Precision Performance of Quantitative Measurement Methods; Approved Guideline—Second Edition. NCCLS document EP5-A2 (ISBN 1-56238-542-9). NCCLS, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898 USA, 2004.

E.  James O. Westgard, Online Validation Training, Westgard QC, Inc. www.westgard.com, Module 10: Determining Imprecision.

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