Table 2
Accuracy of pH test under cut-offs 1–9
pH cut-offs
Sensitivity (stomach)
Specificity
(lung)
Specificity (oesophagus)
1
0.015
1
1
2
0.257
1
1
3
0.39
1
1
4
0.544
1
0.985
5
0.68
1
0.948
5.5
0.743
1
0.81
6
0.81
0.996
0.792
7
0.914
0.91
0.492
8
0.991
0.337
0.225
9
1
0.004
0.068