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Document 2 of 2 – 3M Petrifilm Salmonella Express PTM Study Report
Table 29. Statistical Analysis (Chi Square) of 3M Salmonella Petrifilm Method Compared to the BAM Method for
1
Detection of Salmonella on Stainless Steel (Independent laboratory Data)
2
Matrix
Level of
Target
Total
Samples
b
Presumptive
Positive
Confirmed
Positive
c
Reference
Positive
d
X
2e
Relative
Sensitivity
False
Positive
Control
5
0
0
0
-
-
Low
20
6
6
7
0.11
100
0.0
Stainless
Steel
3M Petrifilm SALX Method
3
b
Number of test assay positive samples not considering subsequent confirmations
c
Number of test assay positive samples subsequently confirmed
d
Number of samples positive by reference method
e
Mantel-Hansezel chi square
f
Test sensitivity rate is defined as the number of confirmed positive test results divided by the number of test screened
positive results, expressed as a percentage.
g
Test false positive rate is 100 – test specificity rate. Not calculated where the number of samples negative by both
methods is 0.
4
5
6
7
8
9
10
11
12
13
14
15