Objective: To verify the possibility of extending the application of an instrument to investigate the prevalence and clinical characteristics of wheezing in infants.
Methods: A cross-sectional study conducted as part of the International Study on Wheezing in Infants (EISL, Estudio Internacional de Sibilancias en Lactantes). A questionnaire was administered to parents of infants aged 12 to 15 months (group I) and 16 to 24 months (group II) infants.
Results: One thousand, three hundred and sixty-four infants (45.4%) in group I and 250 (46.7%) in group II had had at least one episode (p = 0.58). The numbers of patients on inhaled beta(2)-agonists, inhaled or oral steroids and/or leukotriene modifiers were similar in both groups (p = 0.52, 0.12, 0.06, and 0.75). There were no differences between the groups in terms of night-time symptoms, shortness of breath, emergency room visits, asthma hospitalization or asthma diagnosed by a doctor (p = 0.09, 0.28, 0.54, and 0.45).
Conclusions: The application of the questionnaire can be extended to include infants up to 24 months of age.