Table 3.

Univariate and multivariate analyses of the possible determinants of the introduction of antibiotic therapy upon admission of the 230 patients included in the study.

Category	Antibiotic therapy not introducedn = 104(45.2%)	Antibiotic therapy introducedn = 126(54.8%)		Univariate Analyses			Multivariate Analyses
			RR	95% CI	p-value	RR	95% CI	p-value
RSV (+)*	71 (48.6)	75 (51.4)	0.85	0.59-1.21	0.357	-		-
Age > 6 months	08 (20.5)	31 (79.5)	1.60	1.07-2.40	0.023	0.95	0.61-1.48	0.808
Male	56 (43.4)	73 (56.6)	0.93	0.65-1.32	0.676	-		-
Fever on admission	56 (37.3)	94 (62.7)	1.57	1.05-2.34	0.028	0.93	0.60-1.44	0.745
Thoracic radiography with opacification	18 (18.2)	81 (81.8)	2.41	1.65-3.52	<0.001	1.48	0.94-2.32	0.091
ICU	14 (35.9)	25 (64.1)	1.21	0.78-1.88	0.389	-		-
MV	02 (12.5)	14 (87.5)	1.67	0.96-2.91	0.070	1.30	0.74-2.28	0.370
AOM	00 (00.0)	12 (100)	1.91	1.05-3.47	0.033	4.66	2.28-9.51	<0.001
Pneumonia	01 (1.1)	94 (98.9)	4.17	2.79-6.23	<0.001	4.16	2.53-6.85	<0.001
Leukocyte count*<9,0009-13,000>13,000	15 (31.3)15 (32.6)16 (29.1)	33 (68.7)31 (67.4)39 (70.9)	1.02	0.81-1.28	0.890	-		-
Oximetry %mean (sd)	91 (0.4)	89 (0.4)	0.96	0.92-1.01	0.101	-		-

VIRUS(+) = etiological diagnosis of infection with any respiratory virus; RSV(+) = etiological diagnosis of infection with respiratory syncytial virus; ^*Result unavailable at the moment of introduction of antibiotic therapy; ICU = intensive care unit; MV = mechanical ventilation; AOM = diagnosis of acute otitis media; RR = relative risk; ^#Number of cells/ml; ^##Oximetry was analyzed as a continuous variable, whereas the other variables were categorized.