AOAC ISPAM Stakeholder Panel Meeting Book 3-13-18

Quantitative Microbiology Validation Acceptance Criteria

ƒ Revised Appendix J Guidelines ƒ Log 10

transform data using updated equation

Log 10 [CFU/unit + (0.1)f] f is the reported CFU/unit corresponding to the smallest reportable result

ƒ Modification to Log 10

transformation is to normalize the data and can be

used to evaluate uninoculated control levels (data results with 0) ƒ Plot all data, candidate (Y axis) vs. reference (X axis) – Identify outliers ƒ Perform outlier tests (Cochran and Grubbs) - If data is an outlier can you exclude? Need to justify ƒ Calculate repeatability/standard deviation (s r ) and reproducibility (Collaborative study only) ƒ Additional requirements for OMA methods

Quantitative Microbiology Validation Acceptance Criteria

Statistical Changes

ƒ p value no longer calculated ƒ Difference of Means between candidate and reference method for each contamination level along with 95% Confidence Interval ƒ Report the Reverse Transformed Mean Difference and 95% confidence interval ƒ Workbook provided by AOAC – • Has some limitations • Calculates DOM and 95% CIs but not RTDOM or 95% CIs