Table 1.

 Demographic characteristics of infants hospitalized with bronchiolitis grouped according to severity (percentages are within groups)

Demographic characteristics	Group 0 (n = 193)	Group 1 (n = 53)	Group 2 (n = 48)	Group 3 (n = 16)	p
Birth weight (kg)*	3.1 ± 0.5	3.1 ± 0.4	3.3 ± 0.5	2.8 ± 0.4†	0.02
Gestational age (weeks)*	38.9 ± 1.3	38.8 ± 1.3	38.8 ± 1.4	37.9 ± 1.2‡	0.05
Male gender (%)	58.5	39.6	58.3	43.8	0.07
Cesarian section (%)	46.8	54.7	57.4	75.0†	0.11
Weight on admission (kg)*	5.5 ± 0.2	4.9 ± 0.1	4.7 ± 0.16	3.9 ± 0.8‡	0.001
Postnatal age (days)*	88.6 ± 63.3	63.1 ± 49.7	57.8 ± 52.8	37.4 ± 22.6‡	0.001
Siblings (%)	47.2	50.0	66.7	73.3	0.03

p between groups.

*Mean ± SD.

^†p < 0.05 group 3 vs groups 0, 1, 2.

^‡p < 0.01 group 3 vs groups 0, 1, 2.