AOAC ISPAM Stakeholder Panel Meeting Book 9-24-17

Quantitative Microbiology Validation Acceptance Criteria

ƒ Suggested acceptance criteria has been • < 0.5 Log 10 difference between candidate and reference method is acceptable.

· Where does this come from? Why not 0.25 or 0.75? • If the confidence interval for the difference of means contains the point 0, methods are considered equivalent at that level

Quantitative Microbiology Validation Acceptance Criteria

ƒ Example 1: Independent Lab Study for 1 Matrix. • One Level with a statistical difference according to workbook • <0.5 Log 10 difference between methods

95% Confidence Intervals (LCL, UCL) (Log 10 )

Mean Difference a (Log 10 )

Reference Method

Matrix Contamination Level

-0.1434, 0.0264 -0.4981, -0.0539 -0.0794, 0.0953

Low

-0.0585

Raw Fish

FDA/BAM

Medium

-0.2760

High

0.0800

• Low DOM but still significantly different due to low standard deviations between replicates