[Changes in the prevalence of asthma in Chilean school age children between 1994 and 2002. International Study of Asthma and Allergies in Childhood (ISAAC)--Chile phases I and III].
BACKGROUND
In developed countries, the prevalence of asthma in children has significantly increased in the last decades. However, there is no information about the trends of asthma in Latin America.


OBJECTIVE
To determine changes in asthma prevalence between 1994 and 2002 in Chilean schoolchildren.


METHODS
The prevalence of asthma symptoms in schoolchildren aged 7 (n =18.697) and 13 years (n =18.939), from South Santiago, Valdivia and Punta Arenas, obtained during phases I and III of the ISAAC, carried out in 1994 and 2002, was compared.


RESULTS
From 1994 to 2002, the mean national prevalence of "wheezing in the last 12 months" in the group aged 6-7 years, changed from 18.2% to 17.9% (p =NS); "asthma ever" from 12.5% to 10.7% (p =NS), and "severe episode" from 3.2% to 2.8% (p =NS). There was a significant increase of the prevalence of "wheezing in the last 12 months", in children aged 13-14 years, from 9.8% to 15.5% (p =0.01); in "asthma ever" from 10.2% to 14.9% (p =0.01), and for "severe episode" from 2.8% to 3.8% (p =0.01).


CONCLUSIONS
There was a significant increase in the prevalence of respiratory symptoms related to asthma in children aged 13-14 years that was consistent in all the 3 participating centres of the ISAAC. However, the prevalence of asthma symptoms in children aged 6-7 years remained without significant changes between 1994 and 2002.
Mallol
Javier
J
Departamento de Medicina Respiratoria Infantil, Hospital CRS El Pino, Universidad de Santiago de Chile (USACH), Santiago, Chile. jmallol@usach.cl
Aguirre
Viviana
V
Aguilar
Pedro
P
Calvo
Mario
M
Amarales
Lidia
L
Arellano
Pamela
P
Palma
Rodrigo
R
D000293:Adolescent; D001249:Asthma / Q000453:epidemiology*; D016009:Chi-Square Distribution; D002648:Child; D002677:Chile / Q000453:epidemiology; D006801:Humans; D015995:Prevalence; D012135:Respiratory Sounds; D012720:Severity of Illness Index; D013334:Students; D013997:Time Factors; D014505:Urban Population