Table 3 The association between oxygen therapy and all-cause in-hospital mortality in subgroup analysis
Characteristics | No. of total | No. Ambient Air (No. of deaths) | No. Oxygen Therapy (No. of deaths) | OR (95% CI) | P value |
|---|---|---|---|---|---|
Duration of oxygen therapy (days) | |||||
  ≤ 3 | 741 | – | 741 (40) | 0.87 (0.60–1.27) | 0.472 |
 3–6 | 322 | – | 322 (28) | 1.45 (0.94–2.25) | 0.092 |
  > 6 | 167 | – | 167 (30) | 3.34 (2.15–5.20) | <  0.001 |
Median SpO2 during treatment period (%) | |||||
 90–95 | 753 | 431 (33) | 322 (26) | 1.06 (0.62–1.81) | 0.832 |
  > 95 | 2169 | 1261 (71) | 908 (72) | 1.44 (1.03–2.03) | 0.034 |
Age (years) | |||||
  ≤ 72 | 1498 | 856 (41) | 642 (38) | 1.25 (0.79–1.97) | 0.334 |
  > 72 | 1424 | 836 (63) | 588 (60) | 1.39 (0.96–2.02) | 0.079 |
de novo AHF (n) | |||||
 Yes | 1155 | 659 (58) | 496 (58) | 1.37 (0.92–2.22) | 0.111 |
 No | 1767 | 1033 (46) | 734 (40) | 1.24 (0.85–1.82) | 0.258 |
AF (n) | |||||
 Yes | 668 | 381 (28) | 287 (34) | 1.69 (1.00–2.87) | 0.049 |
 No | 2254 | 1311 (76) | 943 (64) | 1.18 (0.84–1.67) | 0.337 |
MI (n) | |||||
 Yes | 561 | 331 (33) | 230 (22) | 0.96 (0.54–1.69) | 0.874 |
 No | 2361 | 1361 (71) | 1000 (76) | 1.49 (1.07–2.09) | 0.019 |
Stroke (n) | |||||
 Yes | 301 | 178 (14) | 123 (17) | 1.88 (0.89–3.97) | 0.099 |
 No | 2621 | 1514 (90) | 1107 (81) | 1.25 (0.92–1.70) | 0.161 |
Hypertension (n) | |||||
 Yes | 1869 | 1041 (61) | 828 (59) | 1.23 (0.85–1.79) | 0.268 |
 No | 1053 | 651 (43) | 402 (39) | 1.52 (0.97–2.39) | 0.070 |
CKD (n) | |||||
 Yes | 775 | 451 (40) | 324 (36) | 1.28 (0.80–2.07) | 0302 |
 No | 2147 | 1241 (64) | 906 (62) | 1.35 (0.94–1.94) | 0.102 |
RRT (n) | |||||
 Yes | 149 | 102 (4) | 47 (6) | 3.59 (0.96–13.38) | 0.057 |
 No | 2773 | 1590 (100) | 1183 (92) | 1.26 (0.94–1.69) | 0.128 |