Univariate analyses of association between independent variables and readmission
| Variable | Day 14 | Week 6 | Month 3 |
| Admissions in previous year | p=0.02 (OR 2.3, CI 1.1 to 4.7) | p=0.014 (OR 2.0, CI 1.2 to 3.5) | p=0.027 (OR 1.8, CI 1.0 to 3.0) |
| Long-term oxygen therapy | p<0.05 (OR 1.95, CI 0.9 to 3.8) | p<0.001 (OR 3.84, CI 2.2 to 6.7) | p<0.001 (OR 3.5, CI 1.9 to 6.3) |
| Portable oxygen | p=0.51 (OR 1.33, CI 0.6 to 2.9) | p=0.02 (OR 2.76, CI 1.5 to 5.1) | p <0.001 (OR 3.28, CI 1.7 to 6.3) |
| Home nebuliser | p=0.43 (OR 1.38, CI 0.6 to 3.1) | p=0.36 (OR 1.3, CI 0.71 to 2.5) | p=0.24 (OR 1.4, CI 0.8 to 2.7) |
| Oxygen saturation <92% on room air | p=0.28 (OR 1.51, CI 0.7 to 3.3) | p=0.005 (OR 2.17, CI 1.4 to 3.3) | p=0.02 (OR 1.7, CI 1.2 to 2.4) |
| Pack-year history ≥50 | p=0.78 (OR 1.07, CI 0.35 to 3.3) | p=0.03 (OR 3.25, CI 1.5 to 6.9) | p=0.01 (OR 2.86, CI 1.3 to 6.2) |
| Borg scale ≥3 | p=0.026 (OR 2.47, CI 1.2 to 5.1) | p <0.001 (OR 3.23, CI 1.7 to 6.0) | p <0.001 (OR 3.23, CI 1.7 to 6.1) |
| MMRC scale ≥3 | p=0.02 (OR 2.56, CI 1.1 to 5.7) | p=0.01 (OR 2.0, CI 1.1 to 3.6) | p=0.01 (OR 2.0, CI 1.1 to 3.4) |
| Vaccination status (pneumococcal and influenza) | p=0.65 (OR 1.2, CI 0.58 to 2.4) | p=0.8 (OR 1.1, CI 0.61 to 1.9) | p=0.83 (OR 0.94, CI 0.55 to 1.6) |
Pack-year history, number of packets of cigarettes smoked per day × total number of years smoking; Borg scale refers to level of dyspnoea at enrolment; MMRC (modified Medical Research Council) scale ≥3 refers to level of dyspnoea at enrolment.