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JohnsHopkinsUniversity

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Rapid HIV Validation Overview

Author:
Validation Committee / Document Number: / Equ35-F-01
Effective (or Post) Date: / 4 March 2011
Review History / Date of last review: / NA
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.
Rapid HIV Validation Overview / Document Number / 1100
Effective Date / 3 Jun 2009
Subject
Guidelines for validation of a Rapid HIV method / Page / 1 of 1
Supersedes / Version 1.0
Author(s) / Name, Title / Date
Mark Swartz, Heidi Hanes, Jo Shim, Penny Stevens, Anne Sholander / June 2009
Approved by / Name, Title / Date
SMILE Validation Committee / June 2009
Review History / Date of last review: / 15 February 2011
Reviewed by: / Anne Sholander
Revision History / Version # [0.0] / Revision Date [dd/mm/yy] / Description (notes)
1.1 / 02/15/2011 / Updated terminology in Diagnostic Sensitivity and Specificity section

Rapid HIV Validation Overview

Validation consists of an established set of required experiments. After completing all of the validation experiments, raw data and results should be compiled and filed in an organized manner. All validation records should be retained indefinitely. Avalidation summary should be prepared that containsthe signature of the Laboratory Director, indicating the validation has been reviewed and approved.

The following are the required components of validation:

  1. Precision is reproducibility –Not applicable for qualitativerapid tests.
  2. Accuracy is the true value of a substance being measured. Verification of accuracy is the process of determining that the test system is producing true, valid results.
  3. Determine your comparison or reference method
  4. The comparison method must be previously validated.
  5. The comparison method must be currently performing successfully on EQA
  6. Comparison to a method currently in use in the laboratory is preferred if the method meets the above criteria.
  7. Samples with known values, such as proficiency testing samples or commercial standards, may be used as the reference method.
  8. Sample Criteria
  9. A minimum of100 samples for each expected result.
  10. The accuracy study must include 100 confirmed positives and 100 confirmed negatives.
  11. HIV positive patient samples used for accuracy determination must be confirmed positive by a validated Western Blot or PCR method.
  12. HIV negative patient samples used for accuracy determination must be confirmed negative by a validated, FDA approved HIV EIA method or by two different validated, FDA approved rapid HIV methods.
  13. Patient, quality control, and proficiency testing materials may be used.
  14. Note: if testing will also be performed at clinic sites, it is acceptable to perform an abbreviated validation at the clinics with 20 positive and 20 negative samples provided a full validation has been performed on the same test kit and using the same patient population.
  15. Testing:
  16. Two levels of quality control must be run each day that testing is performed,not including controls internal to the kit cartridge/testing device.
  17. Testing should be performed by at least 2 different testing personnel.
  18. Acceptability criteria:
  19. The performance of qualitative tests is most commonly described in terms of sensitivity and specificity. The table below is a contingency table that compares the results of a qualitative test with the outcome of the diagnostic accuracy criteria. The entry in each cell of the table represents the number of specimens corresponding to the labels in the margins.

Method being Validated / Diagnostic Sensitivity and Specificity
(Results from Comparison Study) / Total
Positive / Negative
Positive / # true positive (TP) / # false positive (FP) / TP+FP
Negative / # false negative (FN) / # true negative (TN) / FN+TN
Total / TP+FN / FP+TN / N
  1. Calculate the estimatedDiagnostic Sensitivity (True positive rate) = 100 x [TP/(TP+FN)]
  2. Calculate the estimated Diagnostic Specificity(True negative rate) = 100 x [TN/(FP+TN)]
  3. Calculate the percent Positive Agreement (Positive Predictive Value)=100 x TP/(TP+FP)
  4. Calculate the percent Negative Agreement (Negative Predictive Value) =100 x TN/(TN+FN)
  1. Compare the results calculated above with the manufacturer’s stated claims for Sensitivity, Specificity and Agreement found in the test kit package insert.
  2. Results must be equal to, or greater than, the manufacturer’s claims for the method to be considered accurate.
  1. Linearitywith AMR and CRR–Not applicable for qualitative tests.
  2. Analytical Sensitivity is the lowest concentration of an analyte that can be measured. For an FDA approved, unmodified method, the manufacturer’s stated sensitivitywill be used.
  3. Analytical Specificity is the determination of the effect of interfering substances. For an FDAapproved, unmodified method, the manufacturer’s stated specificity will be used.
  4. Reference Ranges–Can be determined by the laboratory with laboratory director approval. Verification of manufacturer’s stated reference range is not required.
  5. Summary and Approval. See SMILE Rapid HIVValidation Summarytemplate.
  6. References
  7. GCLP Workshop and Workbook18-20 May 2008, Verification of Performance Specifications, pages 1-33.
  8. Clinical and Laboratory Standards Institutes (CLSI), User Protocol for Evaluation of Qualitative Test Performance; Approved Guideline--Second Edition. CLSI document EP12-A2 (ISBN 1-56238-654-9). Clinical and Laboratory Standards Institute, 940 West Valley Road, Suite 1400, Wayne, PA 19087-1898 USA, 2008.
  9. EP Evaluator Release 8, David G. Rhoads Associates Inc.,
  10. James O. Westgard, Online Validation Training, Westgard QC, Inc. Sections 11-Determining Bias,12- Estimating Trueness, and 13- Judging Method Acceptability.

1100_ SMILE Rapid HIV Validation Overview v. 1.1.doc Page 1 of 4 4 December 2018