Patterns in respiratory symptoms up to 7 years old in children from a Spanish birth cohort

Background: Asthma is a heterogeneous syndrome with complex patterns of symptoms whose origin seems to be early in life. Its evolution during childhood is not yet fully understood. Aim: To identify relevant longitudinal patterns of respiratory symptoms until age of 7 years, and the associated factors, in children from a Spanish birth cohort. Methods: Population consisted of 470 children. Symptoms in the last 12 months (wheeze, cough lasting more than 3 weeks, and atopic eczema) were reported by parents at each follow-up (1, 4 and 7 years of age). A clustering analysis method (k-means) was used to identify groups of children with similar patterns of respiratory symptoms over time. Multinomial logistic regression was used to identify the associated factors (history of allergies, individual and socioeconomic factors, and early environmental exposures). Results: Apart from (i) a group of children with low prevalence of symptoms –53.2% of children-, the identified symptomatic patterns were (ii) early transient...