| Acute exacerbation pepsin low | Acute exacerbation pepsin high | p-value | |
| Subjects n | 16 | 8 | |
| Clinical characteristics | |||
| Age yrs | 65±10 | 63±8 | 0.72 |
| Male | 69% (11) | 100% (8) | 0.13 |
| Ever-smoker | 75% (12) | 88% (7) | 0.63 |
| Body mass index | 25.9±4.0 | 23.6±3.8 | 0.19 |
| Prednisone use | 56% (9) | 75% (6) | 0.66 |
| Intubated | 13% (2) | 0% (0) | 0.54 |
| Survival time days | 75 (21–459) | 65 (10–615) | 0.78 |
| Alive at follow-up | 12% (2) | 25% (2) | 0.58 |
| Radiological characteristics | |||
| Hiatal hernia prevalence | 69% (11) | 63% (5) | 0.55 |
| Hiatal hernia diameter cm | 1.5 (0–1.6) | 1.2 (0–1.6) | 0.39 |
| Hiatal hernia height cm | 2 (0–3) | 1 (0–2.3) | 0.34 |
| Ground-glass opacity score % | 18 (6–33) | 18 (7–26) | 0.82 |
| Consolidation score % | 0 (0–2) | 2 (0–8) | 0.16 |
| Honeycombing score % | 10 (3–12) | 4 (2–7) | 0.23 |
| Reticulation score % | 8 (5–27) | 13 (8–24) | 0.50 |
| Overall CT score % | 45 (28–63) | 43 (24–58) | 0.65 |
| BAL fluid characteristics | |||
| Pepsin concentration ng·mL−1 | 30.3 (6–46.8) | 148.4 (92.0–227.0) | <0.01 |
| Total cell count cells·mL−1 | 235 (144–372) | 340 (150–400) | 0.53 |
| Neutrophils % | 23 (8–32) | 10 (2–13) | 0.10 |
| Lymphocytes % | 8 (5–18) | 38 (26–65) | <0.01 |
| Alveolar macrophages % | 57 (38–65) | 46 (22–56) | 0.11 |
| Eosinophils % | 2 (0–7) | 3 (0–6) | 0.83 |
| Red blood cell count cells·mL−1 | 770 (244–5875) | 390 (130–750) | 0.24 |
Data are presented as mean±sd or median (interquartile range), unless otherwise stated. CT: computed tomography.