Variable | Univariate analysis p value | Multivariate analysis | |||
---|---|---|---|---|---|

Odds ratio | p value | ||||

At enrolment | |||||

H^{+}
| <0.001 | 1.23 (1.05 to 1.43) per nmol/l | <0.01 | ||

Pao_{2}
| 0.035 | ||||

Paco
_{2}
| <0.001 | 1.77 (1.28 to 2.45) per kPa | <0.01 | ||

Allocation to NIV | 0.038 | ||||

At 1 hour | |||||

Fall in H^{+}
| 0.119 | ||||

Change in Pao
_{2}
| 0.193 | ||||

Change in Paco
_{2}
| 0.276 | ||||

Change in respiratory rate | 0.209 | ||||

At 4 hours | |||||

Fall in H^{+}
| 0.035 | 0.89 (0.82 to 0.97) per nmol/l | <0.01 | ||

Change in Pao
_{2}
| 0.896 | ||||

Change in Paco
_{2}
| 0.104 | ||||

Change in respiratory rate | 0.009 | 0.92 (0.84 to 0.99) per breath/min | 0.04 |

Paco

_{2}, Pao_{2}= arterial carbon dioxide and oxygen tensions; NIV = non-invasive ventilation.