Table 2. Hazard ratios for the association of baseline variables with hazard of death.

Group	Variable1	HR2	95%CI	HR3	95%CI	HR4	95%CI
Demographic variables	Male	1.34	0.80–2.27
	Age1	1.09	1.07–1.12	1.09	1.07–1.11	1.03	1.01–1.06
	Retirement home	1.19	0.64–2.22
Comorbidities and medications on admission	BADL dependence	2.98	1.57–5.64	2.51	1.38–3.94
	Hypertension	1.48	0.80–2.71
	Diabetes mellitus	2.55	1.53–4.26	2.33	1.38–3.94	2.42	1.43–4.09
	Prior lung disease	0.93	0.52–1.64
	Chronic kidney failure	0.97	0.51–1.83
	Cardiovascular disease	1.93	1.08–3.46
	Multiple medications	1.57	0.90–2.74
Symptoms on admission	Low-grade fever	0.61	0.32–1.16
	Cough	1.40	0.69–2.84
	Productive cough	1.02	0.57–1.80
	Haemoptysis	0.94	0.13–6.84
	Dyspnoea	1.64	0.94–2.84
	Anosmia	0.26	0.06–1.09
	Ageusia	0.11	0.02–0.83	0.11	0.02–0.83
	Headache	1.25	0.40–3.88
	Nausea	0.64	0.28–1.44
	Muscle tiredness	0.75	0.45–1.26
	Myalgia	0.60	0.33–1.09
	Odynophagia	1.73	0.74–4.04
	Diarrhoea	0.57	0.27–1.22
	General malaise	1.28	0.74–2.21
	Gastrointestinal symptoms	0.58	0.29–1.16
	Fatigue	0.76	0.46–1.26
	Duration of symptoms (days)1	0.98	0.91–1.05
Physical exam on admission	Fever	2.00	1.11–3.60
	Baseline SatO21	0.93	0.91–0.95
	Need for O2	5.17	2.35–11.41
	FiO21	1.05	1.03–1.07
	SatO2/FiO21	0.43	0.33–0.56	0.44	0.34–0.58	0.57	0.43–0.77
X-Ray findings on admission	Opacities	2.93	1.24–6.92
	Interstitial opacities	2.37	1.28–4.40	2.36	1.24–4.49
	Hilar congestion	1.28	0.71–2.32
	Pleural effusion	1.21	0.60–2.43

¹ Quantitative variables. Hazard ratios are expressed as increments in the hazard of death per unit increase in the variable. For dichotomous variables, the reference category was No or Absent.

² Hazard ratios adjusted by age.

³ Hazard ratios obtained with stepwise regression models including age and the remaining variables in each group.

⁴ Hazard ratios obtained with a stepwise regression model including all variables retained in the models fitted for each group of variables.

BADL, Basic activities of daily living.