TABLE 3

Disease severity, complications and outcomes in the influenza and non-influenza viral infection groups

	Influenza viral infection^#	Non-influenza viral infection^¶	Mixed viral infection⁺	p-value
Patients	581	240	94
CURB-65 ≥3 on admission	28/571 (4.9)	9/238 (3.8)	3 (3.2)	0.486
P_aO₂/F_IO₂ <200 mmHg on admission	46/534 (8.6)	12/234 (5.1)	4/87 (4.6)	0.092
Complications during hospitalisation
Sepsis	233 (40.1)	95 (39.6)	39 (41.5)	0.890
Hypoxaemia^§	214/534 (40.1)	87/234 (37.2)	39/87 (44.8)	0.449
ICU admission	48 (8.3)	13 (5.4)	2 (2.1)	0.157
Invasive mechanical ventilation	30 (5.2)	5 (2.1)	1 (1.1)	0.056
Length of hospital stay days	10.0 (8.0–14.0)	10.0 (7.0–14.0)	11.0 (8.0–14.3)	0.986
In-hospital mortality	16 (2.8)	1 (0.4)	1 (1.1)	0.062
90-day mortality	22 (3.8)	4 (1.7)	2 (2.1)	0.174

Data are presented as n, n (%) or median (interquartile range), unless otherwise stated. CURB-65: confusion, urea >7 mmol·L⁻¹, respiratory rate ≥30 breaths·min⁻¹, blood pressure <90 mmHg (systolic) or ≤60 mmHg (diastolic), age ≥65 years; P_aO₂: arterial oxygen tension; F_IO₂: inspiratory oxygen fraction; ICU: intensive care unit. ^#: only influenza virus with or without co-infection; ^¶: any non-influenza respiratory viruses with or without co-infection; ⁺: any two or more viruses; ^§: P_aO₂/F_IO₂ <300 mmHg. p-values are for the influenza viral infection group versus the non-influenza viral infection group.