R. Ronchetti et al., Is the increase in childhood asthma coming to an end? Findings from three surveys of schoolchildren in Rome, Italy, EUR RESP J, 17(5), 2001, pp. 881-886
Time trends in the prevalence of asthma, family history of asthma and atopy
in Roman schoolchildren were assessed. The study population consisted of a
ll children (aged 6-14 yrs) attending two primary schools in Rome, situated
in urban areas that differed markedly in socioeconomic conditions and envi
ronmental pollution. Three questionnaire-based surveys were conducted in 19
74, 1992 and 1998 in 2,259, 1,229 and 1,139 children. The prevalence of ast
hma in males and females increased significantly during 1974-1992 and remai
ned stable from 1992-1998. In age groups born in the subsequent 4-yr period
s it increased almost linearly, for children born from 1962-1965 to 1982-19
85 (4.4%-12.5%), and remained remarkably stable in children born after 1985
. Because the prevalence of asthma had a steeper trend in males than In fem
ales (approximately 0.55%(.)yr(-1) versits 0.25%(.)yr(-1)), the male:female
asthma ratio increased (1:38 in 1974; 1:84 in 1992 and 1:62 in 1998). No s
ingle environmental factor,, including area of residence, seemed to influen
ce the prevalence of asthma. Family history of asthma and atopy also increa
sed steadily (0.72%-respectively) more than doubling during the 24-yr study
period. The strong relationship between asthma and a family history of ato
py not only persisted but also strengthened over time (23.3% of asthmatic c
hildren belonged to families with atopic illnesses in 1974 but 44.2% in 199
8). The environmental factors that might explain the almost three-fold rise
in childhood asthma between 1974 and 1992 remain unknown but the genetic b
ackground of the disease has presumably remained unchanged since the early
1970s. The fact that the prevalence of asthma increased no further during t
he past 6 yrs suggests that the progressive induction of asthma symptoms in
genetically predisposed subjects is a self-limiting process that has proba
bly come to an end in the authors' study area.