Table 2b. Factors associated with weaning failure; multivariate analysis*.

Weaning failure: n = 6339; chi² (12) = 391.95; p < 0.0001	Odds ratio (95% CI)
Reason: postoperative ARI	0.72 [0.59; 0.87]
Reason: acute exacerbation of COPD	1.33 [1.13; 1.56]
Reason: neuromuscular (acute on chronic)	2.98 [1.88; 4.73]
Age at admission (absolute value in years)	2.96 [1.87; 4.69]
Body mass index (absolute value in kg/m2)	0.38 [0.26; 0.58]
Duration of invasive ventilation prior to transfer to weaning center (days)	4.73 [3.25; 6.89]
ECOG performance status	2.17 [1.73; 2.72]
Pre-existing long-term non-invasive ventilation	1.98 [1.64; 2.40]
COPD	1.20 [1.04; 1.40]
Restrictive thoracic disease	1.57 [1.26; 1.95]
Neuromuscular disease	1.87 [1.43; 2.43]
Arterial hypertension	1.29 [1.04; 1.60]

*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.

ARI, Acute respiratory insufficiency; CI, confidence interval; COPD, chronic obstructive pulmonary disease; ECOG, Eastern Cooperative Oncology Group (the ECOG performance status roughly describes function, activities of daily life, and any dependencies)