Asthma prevalence and risk factors in school children: The RESPIR longitudinal study.

Objectives: To analyze the incidence of wheezing in the first six years of life; the prevalence of asthma at six years of age; and the associated risk factors, in a population from Valencia, Spain.

Methods: A prospective longitudinal study was made of a cohort of 636 newborn infants, with follow-up of the clinical records and the completion of questionnaires up to the age of six years.

Results: The prevalence of asthma at six years of age was 12.