Table 4.

Mixed-effects Weibull proportional hazard regression analyses for 3-month mortality (aHR (95% CI, p-value))

	Model-1	Model-2	Model-3
ADL continuous	0.84 (0.80–0.89, p < 0.001)	0.91 (0.87–0.96, p 0.001)	0.88 (0.82–0.94, p < 0.001)
ADL binary (ADL < 6)	1.83 (1.50–2.21, p < 0.001)	1.34 (1.09–1.65, p 0.006)	1.53 (1.19–1.97, p 0.001)
ADL binary (ADL < 5)	1.75 (1.44–2.13, p < 0.001)	1.23 (0.99–1.52, p 0.060)	1.57 (1.21–2.03, p 0.001)
Frailty or disability (ADL < 6 or CFS ≥ 5)	1.77 (1.39–2.25, p < 0.001)	1.51 (1.22–1.88, p < 0.001)	1.88 (1.47–2.40, p < 0.001)
Frailty and disability	2.43 (1.87–3.16, p < 0.001)	1.58 (1.19–2.10, p 0.002)	1.94 (1.39–2.71, p < 0.001)

aHR adjusted hazard ratio, ADL Activities of Daily Living, CFS Clinical Frailty Scale, ICU intensive care unit, SOFA Sequential Organ Failure Assessment

Model-1: Individual ICU as random effect, and ADL/CFS as fixed effects

Model-2: Model-1 plus SOFA, gender, age

Model-3: Model-2 plus ICU beds per 100.000 per country and the local COVID-19 incidence on the day of ICU admission