| Variable | Controls (n = 166) (n (%)) | Cases (n = 83) (n (%)) | OR (95% CI) | p Value |
| Diabetes mellitus | 30 (18.1) | 30 (36.1) | 2.598 (1.40–4.81) | 0.002 |
| Hypertension | 109 (65.7) | 63 (75.9) | 1.771 (0.93–3.38) | 0.082 |
| Coronary artery disease | 97 (58.4) | 53 (63.9) | 1.371 (0.72–2.61) | 0.339 |
| Heart failure | 60 (36.1) | 24 (28.9) | 0.651 (0.34–1.25) | 0.198 |
| Immunosuppression | 2 (1.2) | 4 (4.8) | 6.606 (0.72–60.86) | 0.096 |
| Chronic renal failure | 4 (2.4) | 2 (2.4) | ||
| Hepatic insufficiency | 2 (1.2) | 2 (2.4) | 2.000 (0.28–14.19) | 0.488 |
| Asthma | 10 (6.0) | 8 (9.6) | 1.600 (0.63–4.05) | 0.322 |
| COPD | 14 (8.4) | 15 (18.1) | 2.689 (1.15–6.31) | 0.023 |
| Smoking | 83 (50) | 56 (70) | 2.43 (1.31–4.51) | 0.005 |
| Alcohol | 40 (24) | 28 (35) | 1.86 (1.00–3.50) | 0.055 |
ALI, acute lung injury; COPD, chronic obstructive pulmonary disease.