Table I.

Characteristics and outcomes of all inpatients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or influenza virus infection (all)/subgroup of patients with acute respiratory main diagnosis (RMD)

	SARS-CoV-2 waves					Influenza virus
	Pre-Omicron			Omicron
	Wild-type	Alpha	Delta	BA.1/BA.2	BA.5
In-hospital stay
Number of cases (all/RMD)	176/128	128/103	133/101	320/95	370/91	182/86
Acute RMD (%)	73%	80%	76%	30%	25%	47%
Mean length of stay (days) (all/RMD)	10.8/11.2	10.4/11.3	10.2/11.6	7.2/9.2	6.2/7.2	8.3/7.7
Demographic data
Mean age (years) (all/RMD)	67.5/67.6	62.3/64.7	63.4/67.0	60.7/68.6	64.4/76.0	66.0/69.4
Male gender (%) (all/RMD)	59.7/66.4	46.9/52.4	51.9/55.4	43.1/58.9	44.9/57.1	51.1/57.0
Comorbidities
Diabetes mellitus (%) (all/RMD)	31.8/28.1	27.3/29.1	23.3/25.7	23.8/27.4	22.2/33.0	28.0/36.0
Arterial hypertension (%) (all/RMD)	74.4/77.3	65.6/70.9	63.9/70.3	49.1/58.9	51.6/79.1	56.6/65.1
Cancer (%) (all/RMD)	4.5/3.1	0.8/1.0	3.8/3.0	6.6/1.1	5.4/3.3	3.3/2.3
Chronic renal failure (%) (all/RMD)	28.4/29.7	25.0/25.2	24.1/29.7	22.2/34.7	18.9/28.6	23.6/29.1
Haematological disease (%) (all/RMD)	1.7/2.3	3.1/3.9	4.5/5.9	2.2/4.2	4.3/4.4	4.4/5.8
Neurological disorder (%) (all/RMD)	24.4/23.4	17.2/16.5	15.8/14.9	22.5/23.2	18.6/28.6	19.2/17.4
Respiratory disorder (%) (all/RMD)	10.8/11.7	16.4/18.4	15.0/14.9	13.4/20.0	10.8/16.5	22.0/29.1
Chronic heart disease (%) (all/RMD)	32.4/33.6	20.3/24.3	21.8/20.8	18.8/25.3	22.4/37.4	34.1/32.6
Outcomes
Death (%) (all/RMD)	19.3/22.7	17.2/16.5	15.0/17.8	9.1/12.6	7.0/12.1	8.8/10.5
ICU admission (%) (all/RMD)	27.3/33.6	18.0/21.4	17.3/20.8	8.1/7.4	3.2/3.3	7.1/5.8
Requirement for MV (%) (all/RMD)	18.2/25.0	7.8/9.7	7.5/9.9	3.1/2.1	1.6/2.2	2.7/2.3
Requirement for ECMO (%) (all/RMD)	4.0/5.5	0.8/1.0	1.5/2.0	0.0/0.0	0.0/0.0	0.0/0.0

ICU, intensive care unit; MV, mechanical ventilation; ECMO, extracorporeal membrane oxygenation.