AOAC GFA Stakeholder Program Meeting Book (March 15, 2023)

4.2.3 Data Analysis and Reporting For the matrix / POD study, analyze the data for positive or negative responses, and prepare a table listing the matrix, gluten source, gluten level, number of samples tested ( N ), number of positive responses ( x ), POD and 95% lower confidence limit (LCL) and upper confidence limit (UCL) of the POD, as well as POD curves (LaBudde, R.A. (2009) Coverage Accuracy for Binomial Proportion 95% Confidence Intervals for 12 to 100 Replicates, TR297, Least Cost Formulations, Ltd, Virginia Beach,VA, http://www.lcfltd.com/Documents/tr297%20coverage%20accuracy%20bi nomial%20proportions.pdf). Gluten concentrations at and above the CDC must produce a POD of 0.95 or greater. Blanks samples must produce a POD of 0.05 or lower. To calculate LCL and UCL are artificial numbers and not helpful for a user of these kind of test kit; what is needed is a confidence level of a concentration and not of a POD LaBudde Tech reference – The Stats Committee is working on a revision to bring all qualitative stats up to the latest science. This TR from LaBudde will be obsolete soon. Better citation would be Appendix J and Appendix N of OMA.

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