Table 3

OR for mortality

	OR	95% CI	χ²	P value
Age	1.08	1.02 to 1.15	7.22	0.007*
Clinical frailty score
CFS 1–4	Ref			0.617
CFS 5–9	1.56	0.27 to 11.09	0.25	0.617
Oxygen therapy prior to respiratory support
Moderate	Ref			0.088
High	4.18	0.81 to 29.70	2.91	0.088
Full proning
Unsuccessful	Ref			0.031^*
Successful	0.06	0.00 to 0.80	4.68	0.031^*
CPAP
Required transfer onto HFNO	Ref			0.761
Required CPAP only	0.76	0.13 to 4.88	0.09	0.761

Multivariate logistic regression (Firth bias reduced).
*p<0.05
CFS, clinical frailty score; CPAP, continuous positive airway pressure; HFNO, high flow nasal oxygen.