Table 2c. Factors associated with the need for long-term NIV; multivariate analysis*.

Initiation of NIV: n = 7207; chi² (17) = 1357.5; p <0.0001	Odds ratio (95% CI)
Reason: postoperative ARI	0.77 [0.64; 0.91]
Reason: obesity hypoventilation (acute on chronic)	2.78 [1.76; 4.39]
Reason: acute exacerbation of COPD	1.84 [1.59; 2.14]
Reason: neuromuscular (acute on chronic)	3.64 [2.16; 6.14]
Reason: ALI/ARDS	0.71 [0.51; 0.99]
Reason: trauma/burns	0.36 [0.17; 0.74]
Reason: other	0.76 [0.62; 0.93]
Age at admission (absolute value in years)	0.32 [0.21; 0.49]
Body mass index (absolute value in kg/m2)	3.68 [2.41; 5.63]
Pre-existing long-term non-invasive ventilation	6.28 [5.13; 7.67]
COPD	2.02 [1.77; 2.30]
Restrictive thoracic disease	1.82 [1.44; 2.30]
Obesity [ever]	1.30 [1.12; 1.52]
Coronary heart disease	0.88 [0.77; 0.99]
Arterial hypertension	1.87 [1.54; 2.28]
Delirium	0.70 [0.60; 0.81]
Other [ever]	0.81 [0.72; 0.91]

*Significant parameters are only shown in the final model.

OR values <1 are given in black, OR values > 1 in red.

For continuous parameters, the OR values refer to the maximal range of the parameter from minimum to maximum value; no categorization was undertaken. Wald‘s Chi-square values and p-values are presented in eTable 5.

ALI, Acute lung injury; ARDS, acute respiratory distress syndrome; ARI, acute respiratory insufficiency; CI, confidence interval; COPD, chronic obstructive pulmonary disease; NIV, non-invasive ventilation