From: Screening for tuberculosis and the use of a borderline zone for the interpretation of the interferon-γ release assay (IGRA) in Portuguese healthcare workers
First QFT
Second QFT
Total
Negative
Positive
n
%
657
83.7
128
16.3
785
120
29.0
294
71.0
414
All
777
64.8
422
35.2
1,199
100.0