Number of patients (n) 22,467
Mean age (years) 3.05±1.57 (16 days-18 years)
Male/female (%) 62.8/37.2
Number of patients with acute bronchiolitis (n (%)) 17,809 (79.3)
Number of patients with asthma (n (%)) 4,658 (20.7)
Severity of the attack (%)       
Mild       
Moderate       
Severe

63.7
30.6
5.6
Findings of infection (%)       
Yes       
No

35.5
64.5
Hospitalization (%)      
Yes      
No

22.2
77.8
Table 1: Characteristics of patients admitted to the emergency departments of the four centers.