Table 1. Comparison of baseline characteristics of the study population.
| Variable | Total (n=199) | QFT-GIT-negative group (n=36) | QFT-GIT-positive group (n=163) | P value |
|---|---|---|---|---|
| Age | 55.0 (33.5–73.0) | 65.5 (46.0–76.5) | 52.0 (32.0–72.0) | 0.060 |
| Sex, male | 126 (63.3%) | 20 (55.6%) | 106 (65.0%) | 0.381 |
| BMI, kg/m2 | 21.7 (19.4–23.5) | 21.1 (19.6–22.9) | 21.8 (19.4–23.8) | 0.445 |
| BMI <18, kg/m2 | 14 (7.0%) | 2 (5.6%) | 12 (7.4%) | 1.000 |
| Comorbidities | ||||
| Diabetes | 23 (11.6%) | 4 (11.1%) | 19 (11.7%) | 1.000 |
| ESRD | 15 (7.5%) | 6 (16.7%) | 9 (5.5%) | 0.034 |
| Autoimmune diseases† | 14 (7.0%) | 4 (11.1%) | 10 (6.1%) | 0.287 |
| Malignancy‡ | 7 (3.5%) | 1 (2.8%) | 6 (3.7%) | 1.000 |
| Liver cirrhosis | 5 (2.5%) | 2 (5.6%) | 3 (1.8%) | 0.223 |
| Haematologic malignancy§ | 24 (12.1%) | 8 (22.2%) | 16 (9.8%) | 0.049 |
| HIV infection | 1 (0.5%) | 1 (2.8%) | 0 (0.0%) | 0.181 |
| Pneumoconiosis | 8 (4.0%) | 4 (11.1%) | 4 (2.5%) | 0.037 |
| Smoking status | 0.071 | |||
| Never smoker | 137 (68.8%) | 27 (75.0%) | 110 (67.5%) | |
| Current smoker | 29 (14.6%) | 1 (2.8%) | 28 (17.2%) | |
| Former smoker | 33 (16.6%) | 8 (22.2%) | 25 (15.3%) | |
| Past TB history | 20 (10.1%) | 4 (11.1%) | 16 (9.8%) | 0.764 |
Categorical variables are presented as n (%). Continuous variables are presented as median (IQR). †, systemic lupus erythematosus, rheumatoid arthritis, ankylosing spondylitis, dermatomyositis, polymyositis, systemic sclerosis and ulcerative colitis were included in autoimmune diseases; ‡, bladder cancer, hepatocellular carcinoma, gastric cancer, ovary cancer and lung cancer were included in malignancy; §, lymphoma, acute myeloid leukaemia, acute lymphoblastic leukaemia, MDS, HLH, ITP and multiple myeloma were included in haematological malignancy. QFT-GIT, QuantiFERON-TB Gold In-Tube; BMI, body mass index; ESRD, end-stage renal disease; HIV, human immunodeficiency virus; TB, tuberculosis; IQR, interquartile range; MDS, myelodysplastic syndrome; HLH, hemophagocytic lymphohistiocytosis; ITP, immune thrombocytopenia.