Baseline characteristics of the study sample, stratified according to use of home oxygen therapy
| Characteristics | Before matching (N=36 761) | After matching (1:1; N=2478) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Yes, n (%) | No, n (%) | p Value | Yes, n (%) | No, n (%) | p Value | |||||
| 1330 | (3.6) | 35 431 | (96.4) | 1239 | (50.0) | 1239 | (50.0) | |||
| Age (years), mean (SD) | 67.1 | (9.6) | 63.8 | (12.0) | <0.0001 | 67.4 | (9.7) | 68.0 | (9.9) | 0.14 |
| Sex | ||||||||||
| Male | 964 | (4.7) | 19 353 | (95.3) | <0.0001 | 884 | (49.2) | 912 | (50.8) | 0.21 |
| Female | 367 | (2.2) | 16 078 | (97.8) | 355 | (52.0) | 327 | (48.0) | ||
| Health insurance type | ||||||||||
| National health insurance | 1279 | (3.8) | 32 645 | (96.2) | <0.0001 | 1188 | (50.5) | 1163 | (49.5) | 0.02 |
| Medical aid | 51 | (1.8) | 2786 | (98.2) | 51 | (40.2) | 76 | (59.8) | ||
| Charlson Comorbidity Index* | ||||||||||
| 0 | 692 | (6.5) | 9983 | (93.5) | <0.0001 | 628 | (48.4) | 670 | (51.6) | 0.13 |
| 1 | 62 | (5.7) | 1021 | (94.3) | 57 | (47.1) | 64 | (52.9) | ||
| ≥2 | 576 | (2.3) | 24 427 | (97.7) | 554 | (52.3) | 505 | (47.7) | ||
| ICU use | ||||||||||
| Yes | 11 | (6.9) | 148 | (93.1) | <0.0001 | 9 | (39.1) | 12 | (60.9) | 0.30 |
| No | 1319 | (3.6) | 35 283 | (96.4) | 1230 | (50.1) | 1225 | (49.9) | ||
| Number of hospital admissions | ||||||||||
| 0 | 1147 | (3.5) | 31 923 | (96.5) | <0.0001 | 1067 | (51.5) | 1004 | (48.5) | 0.002 |
| 1 | 127 | (4.9) | 2486 | (95.1) | 119 | (40.6) | 174 | (59.4) | ||
| ≥2 | 56 | (5.2) | 1022 | (94.8) | 53 | (46.5) | 61 | (53.5) | ||
| Respiratory impairment rating | ||||||||||
| Grade 1 (predicted FEV1 ≤25% or PaO2 ≤55 mm Hg) | 163 | (43.2) | 214 | (56.8) | <0.0001 | 91 | (43.1) | 120 | (56.9) | 0.001 |
| Grade 2 (predicted FEV1 ≤30% or PaO2 ≤60 mm Hg) | 121 | (35.6) | 219 | (64.4) | 102 | (55.7) | 81 | (44.3) | ||
| Grade 3 (predicted FEV1 ≤40% or PaO2 ≤65 mm Hg) | 110 | (26.6) | 304 | (73.4) | 110 | (61.1) | 70 | (38.9) | ||
| No grade | 936 | (2.6) | 34 694 | (97.4) | 936 | (49.2) | 968 | (50.8) | ||
*Calculated comorbidity component; subtracted age scores.
ICU, intensive care unit.