Table 1.
Baseline characteristics of patients with interstitial lung disease (n = 1972) and controls (n = 310,547)
| Variable | Interstitial lung disease No. (%) | Control No. (%) | P value | ||
|---|---|---|---|---|---|
| Sex | |||||
| Male | 1265 | (64.1) | 151,124 | (48.7) | < 0.001 |
| Female | 707 | (35.9) | 159,423 | (51.3) | |
| Age group (years) | |||||
| 40–49 | 354 | (18.0) | 136,576 | (44.0) | < 0.001 |
| 50–59 | 474 | (24.0) | 89,952 | (29.0) | |
| 60–69 | 662 | (33.6) | 57,189 | (18.4) | |
| ≥ 70 | 482 | (24.4) | 26,830 | (8.6) | |
| Baseline comorbidity | |||||
| Malignancy | 357 | (18.1) | 43,007 | (13.8) | < 0.001 |
| Diabetes | 479 | (24.3) | 48,507 | (15.6) | < 0.001 |
| Chronic renal failure | 27 | (1.4) | 2187 | (0.7) | < 0.001 |
| COPDa | 242 | (12.3) | 11,204 | (3.6) | < 0.001 |
| Past history | |||||
| Herpes (B00, B02) | 65 | (3.3) | 9997 | (3.2) | 0.85 |
| Tuberculosis (A15, A16, B90) | 102 | (5.2) | 5467 | (1.8) | < 0.001 |
| Pneumonia (J12-J18) | 98 | (5.0) | 6709 | (2.2) | < 0.001 |
| Hepatitis C (B18.2) | 28 | (1.4) | 2068 | (0.7) | < 0.001 |
| Hepatitis B (B18.0, B18.1) | 66 | (3.3) | 9859 | (3.2) | 0.66 |
| GERDb (K21) | 227 | (11.5) | 26,643 | (8.6) | < 0.001 |
| Smoker (ex-smoker or current smoker) | 748 | (37.9) | 93,573 | (30.1) | < 0.001 |
| Household income (Quartiles), % | |||||
| 81–100 | 870 | (44.1) | 131,363 | (42.3) | 0.11 |
| 41–80 | 635 | (32.2) | 107,310 | (34.6) | |
| 11–40 | 437 | (22.2) | 66,372 | (21.4) | |
| 0–10 | 30 | (1.5) | 5502 | (1.8) | |
aCOPD chronic obstructive pulmonary disease, b GERD gastroesophageal reflux disorder