Table 3.

Cox regression analysis in multiple-imputation data set

Parameter	Univariable Cox regression			Multivariable Cox regression
	HR	95% CI	P-value	HR	95% CI	P-value
Sex	1.125	0.720–1.757	0.650
Age (years)	1.075	1.055–1.096	<0.001	1.068	1.043–1.093	<0.001
Comorbidities
Current smoker	0.735	0.246–2.197	0.581
Obesity (BMI > 25)	0.779	0.498–1.218	0.273
Diabetes type II	1.317	0.835–2.077	0.237
Hypertension	1.838	1.156–2.920	0.010	1.136	0.692–1.865	0.613
Cardiovascular disease (any)	3.493	2.248–5.427	<0.001	1.246	0.711–2.183	0.442
Chronic obstructive pulmonary disease	1.682	0.935–3.024	0.082
Asthma	0.829	0.261–2.627	0.750
Hypo-/hyperthyroidism	1.196	0.617–2.319	0.597
Chronic renal insufficiency	3.466	2.205–5.448	<0.001	1.579	0.937–2.662	0.086
Chronic liver disease	0.689	0.252–1.883	0.468
Malignancy	1.978	1.163–3.364	0.012	2.054	1.184–3.561	0.010
Symptoms at admission
Asymptomatic	0.401	0.105–1.527	0.180
Fatigue	1.054	0.690–1.610	0.806
Cough	0.634	0.414–0.972	0.036	0.850	0.537–1.346	0.489
Fever	1.324	0.838–2.091	0.229
Requirement of oxygen	2.077	1.306–3.304	0.002	1.639	1.001–2.682	0.050
Dyspnoea	1.205	0.788–1.842	0.389
Diarrhoea	0.583	0.301–1.130	0.110
Sore throat	0.185	0.027–1.259	0.085
Nausea or vomiting	0.897	0.449–1.791	0.758
Vital Signs at admission
Temperature (°C)	0.882	0.698–1.114	0.291
Pulse rate (beats per minute)	0.988	0.973–1.003	0.128
Systolic arterial pressure (mmHg)	0.997	0.986–1.008	0.637
Diastolic arterial pressure (mmHg)	0.989	0.968–1.010	0.290
Respiratory rate (b.p.m.)	1.006	0.981–1.033	0.633
SpO2 at ambient air (%)	0.933	0.881–0.988	0.017	1.038	0.957–1.125	0.368
COVID-19 classification at admissiona	1.654	1.303–2.099	<0.001	1.639	1.234–2.176	0.001
Clinical characteristics
Admission to ICU	1.161	0.738–1.827	0.517
Invasive ventilation	1.196	0.722–1.982	0.487
Anticoagulation
LMWH	0.413	0.270–0.634	<0.001	0.561	0.348–0.906	0.018
NOAC	0.750	0.376–1.495	0.413
Additional treatment
Corticosteroids	0.611	0.366–1.019	0.059
Remdesivir/Favipiravir	1.082	0.648–1.805	0.764
Lopinavir/Ritonavir	0.475	0.219–1.031	0.060
Camostat	0.044	0.001–1.829	0.101

BMI, body mass index; CI, confidence interval; HR, hazard ratio; ICU, intensive care unit; LMWH, low-molecular-weight heparin; mmHg, millimetre mercury; NOAC, non-vitamin K oral anticoagulants; SpO₂, peripheral capillary oxygen saturation.

^aCOVID-19 classification was performed according to the guidelines issued by the WHO in mild (fever <38°C, no dyspnoea, no pneumonia), moderate (fever, respiratory symptoms, pneumonia), severe (respiratory distress with respiratory rate ≥30 b.p.m., SpO₂ < 93% at rest), and critical (respiratory failure with requirement of mechanical ventilation, requirement of ICU).