Table 4.

Factors associated with pneumonia occurrence (n = 385) among hospitalized patients with influenza-like illness in multivariable logistic regression (excluding patients infected with both respiratory syncytial virus (RSV) and influenza virus)

	n/N (%)	Crude OR (95% CI)	p	Adjusted OR (95% CI)	p
Agea	—	1.1 (0.9–1.5)	0.20	1.0 (0.9–1.1)	0.20
Chronic respiratory disease			0.7		0.9
No	206/784 (26)	1		1
Yes	179/657 (27)	1.1 (0.8–1.3)		1.0 (0.8–1.2)
Chronic cardiac disease			0.03	—	—
No	205/835 (25)	1
Yes	180/606 (30)	1.3 (1.0–1.6)
Diabetes			0.9	—	—
No	291/1025 (27)	1
Yes	94/356 (26)	0.9 (0.7–1.3)
Chronic renal failure			0.001		0.001
No	313/1249 (25)	1		1
Yes	72/192 (38)	1.8 (1.3–2.5)		1.8 (1.3–2.5)
Cancer			0.15	—	—
No	314/1210 (26)	1
Yes	71/232 (31)	1.3 (0.9–1.7)
Immunosuppressive treatment			0.6	—	—
No	323/1222 (26)	1
Yes	62/220 (28)	1.1 (0.8–1.5)
Influenza vaccination			0.5	—	—
No	205/783 (26)	1
Yes	177/640 (28)	1.1 (0.9–1.4)
Active smoking			0.02		0.02
No	170/705 (24)	1		1
Yes	212/722 (29)	1.3 (1.0–1.7)		1.3 (1.0–1.7)
RSV infection			0.005		0.008
No	362/1390 (26)	1		1
Yes	23/52 (44)	2.3 (1.3–3.9)		2.1 (1.2–3.8)
Influenza virus infection			0.4	—	—
No	228/882 (26)	1
Yes	157/760 (28)	1.1 (0.9–1.4)	0.4

The outcome analysed was the occurrence of pneumonia during the hospital stay (n = 385).

The multivariate model was adjusted for 'chronic respiratory disease' and 'age >65'.

^aContinuous variable.