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Table 12. BAX® System Presumptive vs. Confirmed Results – Environmentals
Sample Type Media
CFU/
sample
Test
Portions
BAX® Presumptive
BAX® Confirmed
dPOD
CP
e
95% CI
f
X
b
POD
CP
c
95% CI
f
X
b
POD
CC
d
95% CI
f
Ceramic tile
LB
Control
5
0
0
(0, 0.43)
0
0
(0, 0.43)
0
(-0.45, 0.45)
60
20
9
0.45
(0.26, 0.66) 9
0.45
(0.26, 0.66)
0
(-0.14, 0.14)
600
5
5
1.0
(0.57, 1.0)
5
1.0
(0.57, 1.0)
0
(-0.45, 0.45)
Ceramic tile
BPW
Control
5
0
0
(0, 0.43)
0
0
(0, 0.43)
0
(-0.45, 0.45)
60
20
6
0.30
(0.15, 0.52) 6
0.30
(0.15, 0.52)
0
(-0.14, 0.14)
600
5
5
1.0
(0.57-1.0)
5
1.0
(0.57, 1.0)
0
(-0.45, 0.45)
Plastic
LB
Control
5
0
0
(0, 0.43)
0
0
(0, 0.43)
0
(-0.45, 0.45)
107
20
13
0.65
(0.43, 0.82) 13
0.65
(0.43, 0.82)
0
(-0.14, 0.14)
1070
5
5
1.0
(0.57, 1.0)
5
1.0
(0.57, 1.0)
0
(-0.45, 0.45)
Plastic
BPW
Control
5
0
0
(0, 0.43)
0
0
(0, 0.43)
0
(-0.45, 0.45)
107
20
11
0.55
(0.34, 0.74) 11
0.55
(0.34, 0.74)
0
(-0.14, 0.14)
1070
5
5
1.0
(0.57, 1.0)
5
1.0
(0.57, 1.0)
0
(-0.45, 0.45)
b
X = Number of positive test portions
2
c
POD
CP
=
Candidate method presumptive positive outcomes divided by the total number of trials
3
d
POD
CC
= Candidate method confirmed positive outcomes divided by the total number of trials
4
e
dPOD
CP
= Difference between the candidate method presumptive result and candidate method confirmed result POD values
5
f
95% CI = If the confidence interval of a dPOD does not contain zero, then the difference is statistically significant at the 5% level
6
7
8
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