AOAC-RI ERP Book MICRO Sept 2016.pdf

Document 2 of 2 – 3M Petrifilm Salmonella Express PTM Study Report

Table 30. Statistical Analysis (POD) of 3M Salmonella Petrifilm Method Confirmed vs. Reference Method 1 (Independent Laboratory Data) 2

3M Petrifilm SALX Method Confirmed

MPN a /25g (or 100g for egg)

Reference Method

dPOD C f

N b

95% CI g

Matrix

X c

d

X c

e

POD c

95% CI

POD R

95% CI

-0.435- 0.435 -0.237- 0.326 -0.435- 0.435 -0.322- 0.233 -0.435- 0.435

N/A h

5

0

0.000

0.000-0.435

0

0.000

0.000-0.435

0.000

Ground Chicken

0.79

20

12

0.600

0.387-0.781

11

0.550

0.342-0.742

0.050

N/A h

5

0

0.000

0.000-0.435

0

0.000

0.000-0.435

0.000

Pasteurized Liquid Egg

0.80

20

7

0.350

0.181-0.567

8

0.400

0.219-0.313

-0.050

N/A h

5

0

0.000

0.000-0.435

0

0.000

0.000-0.435

0.000

Stainless Steel -0.317- 0.226 a MPN = Most Probable Number is based on the POD of reference method test portions using the AOAC MPN calculator, with 95% confidence interval b N = Number of test portions c x = Number of positive test portions d PODC = Confirmed candidate method positive outcomes divided by the total number of trials e PODR = Confirmed reference method positive outcomes divided by the total number of trials f dPODC = Difference between the candidate method and reference method POD values g 95% CI = If the confidence interval of a dPOD does not contain zero, then the difference is statistically significant at the 5% level h N/A = Not applicable N/A h 20 6 0.300 0.145-0.519 7 0.350 0.181-0.567 -0.050

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