Characteristics of the index admission between those with expiratory flow limitation and those without, in the upright position
| Characteristics | All patients | Patients with EFL | Patients with no EFL | p-value |
| Subjects n | 82 | 32 | 50 | |
| Male | 40 (49) | 13 (41) | 27 (54) | 0.31 |
| Female | 42 (51) | 19 (59) | 23 (46) | |
| Age years | 71±10.4 | 70.2±10.2 | 72±10.6 | 0.49 |
| BMI kg·m−2 | 24 (20–29) | 27 (21–36) | 23 (19–26) | 0.03 |
| Current smoker | 24 (29) | 10 (31) | 14 (28) | 0.68 |
| Ex-smoker | 58 (71) | 22 (69) | 36 (72) | |
| Smoking history (pack-years) | 42 (29–56) | 38 (27.5–53) | 42.5 (29–61) | 0.84 |
| Number of exacerbations (within past 12 months) | 2 (1–4) | 3 (1–4) | 2 (1–4) | 0.92 |
| Number of hospitalised exacerbations (<12 months) | 2 (1–3) | 1 (1–3) | 2 (1–3) | 0.61 |
| Pulmonary rehabilitation (<12 months) | 28 (34) | 16 (50) | 12 (24) | 0.02 |
| Charlson Comorbidity Index | 4.3±1.6 | 4.1±1.3 | 4.4±1.7 | 0.23 |
| FEV1 L | 0.86±0.34 | 0.74±0.30 | 0.94±0.36 | 0.01 |
| FEV1% | 34.3±12.4 | 32±12 | 36±13 | 0.25 |
| FVC L | 2.2±2.3 | 1.7 ±0.55 | 2.1 0.63 | 0.009 |
| FVC % | 61±16.7 | 59 ±16.1 | 63 ±17.5 | 0.45 |
| FEV1/FVC % | 43.5±11 | 42±11 | 44±11 | 0.52 |
| IC L | 1.3 (1–1.8) | 1.2 (1–1.8) | 1.4 (1–1.8) | 0.84 |
| PIFR L/m | 60 (50–85) | 60 (50–88) | 62 (50–85) | 0.72 |
| Length of stay in days | 7 (4–10.3) | 7.5 (4.2–11.5) | 8 (5–10.7) | 0.93 |
| CAT score | 31 (27.7–34) | 31 (27–34) | 32 (28.5–34) | 0.52 |
| mMRC | 4 (3.7–4) | 4 (4–4) | 4 (3–4) | 0.54 |
| REFS | 10 (9–12.2) | 10 (10–12) | 10.5 (9–12) | 0.54 |
| Depression | 11 (7–14) | 8 (5.2–12.7) | 11.5 (7.2–14) | 0.08 |
| Anxiety | 9 (6.7–11) | 9 (6.2–12) | 9 (6.2–11) | 0.82 |
| WBCs (109/L) | 10.6 (7.9–14.5) | 10.5 (8–15) | 11 (7.8–14) | 0.70 |
| Eosinophils (109/L) | 0.07 (0.02–0.24) | 0.06 (0.02–0.17) | 0.1 (0.01–0.40) | 0.43 |
| Neutrophils (109/L) | 8 (5.1–11.6) | 8 (5–12) | 8 (6–11) | 0.75 |
| CRP mg·L−1 | 20 (6–62) | 15 (6–70) | 21 (5–70) | 0.61 |
| eGFR mL·min−1 | 85 (65–90) | 70.5 (60–90) | 90 (68–90) | 0.06 |
Data are presented as n (%), mean±sd or median (IQR). BMI: body mass index; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; FEV1/FVC: calculated ratio between both measurements; IC: inspiratory capacity; PIFR: peak inspiratory flow rate; CAT: COPD Assessment Test; mMRC: modified Medical Research Council dyspnoea scale; REFS: Reported Edmonton Frail Scale; WBCs: white blood cells; CRP: C-reactive protein; eGFR: estimated glomerular filtration rate. Data in bold: p<0.05.