Point of viewRecent perspectives on global epidemiology of asthma in childhood
Section snippets
Background
What causes asthma is a pressing question, but the answers remain elusive. Until the mid 1980s most studies of asthma had been undertaken within high income countries whose populations originated from the British Isles, and thus the broader distribution of the prevalence of asthma in the world was largely unknown.1 Studies of the epidemiology of asthma have burgeoned since that time, reflecting worldwide concern that asthma is increasing in prevalence and is an important cause of morbidity not
Global variations in asthma prevalence
Key findings from ISAAC Phase One (1994–1996) included large variations in the worldwide prevalence of symptoms of asthma which were found even among genetically similar populations8, 11 suggesting that environmental factors play an important role.
Further study of the global prevalence and severity of asthma symptoms was undertaken in ISAAC Phase Three, conducted between 2000 and 2003, involving 798,685 adolescents from 233 centres in 97 countries, and 388,811 children from 144 centres in 61
Time trends in asthma prevalence
Most centres who undertook ISAAC Phase One repeated the study after at least five years, reflecting the large worldwide interest in time trends of prevalence. For most centres it was the first opportunity to obtain time trends information. Following reports from English language countries in the 1990s of increases in asthma prevalence from the 1980s, continuing increases in prevalence had been expected. However, ISAAC found that in most high prevalence countries, particularly the English
What environmental factors are important?
The central ISAAC approach has been to study symptoms of disease between populations, which has naturally led to ecological analyses between symptom prevalence values and potential environmental exposures. As Rose states, “the primary determinants of disease are mainly economic and social, and therefore its remedies must also be economic and social”13, and this has been the thrust of the ISAAC approach. If the environment of populations is important in the occurrence of asthma,
The influence of country income and atopy
The ecological economic analysis undertaken in the ISAAC Phase Three global study of asthma prevalence12 revealed a significant trend towards a higher prevalence of current wheeze in centres in higher income countries in both age groups, but this trend was reversed for the prevalence of severe symptoms among children with current wheeze, especially in the adolescents. Although asthma symptoms tended to be more prevalent in high income countries, they appeared to be more severe in low and middle
In conclusion
The asthma epidemic experienced by developed nations over the last 30 years is now affecting developing countries as they become more urbanised. Many of the world's most populous developing countries are now showing similar increases in prevalence of asthma to those experienced in many developed countries. The size of the increases in prevalence implies a large impact on the health of populations. Environmental factors are the key to explain the variations and changes in asthma prevalence. Some
Conflict of interest
Innes Asher is the Chairperson of The International Study of Asthma and Allergies in Childhood.
References (40)
- et al.
Epidemiology of Asthma
Improvement of social environment to improve health
Lancet
(1998)- et al.
Intake of trans fatty acids and prevalence of childhood asthma and allergies in Europe. ISAAC Steering Committee
Lancet
(1999) - et al.
Association between paracetamol use in infancy and childhood, and risk of asthma, rhinoconjunctivitis, and eczema in children aged 6–7 years: analysis from Phase Three of the ISAAC programme
Lancet
(2008) - et al.
Revised nomenclature for allergy for global use: Report of the Nomenclature Review Committee of the World Allergy Organization, October 2003
J Allergy Clin Immunol
(2004) Asthma in Latin America: where the asthma causative/protective hypotheses fail
Allergol Immunopathol (Madr)
(2008)- et al.
Global burden of pediatric respiratory illness and the implications for management and prevention
Pediatr Pulmonol
(2003) - et al.
International Study of Asthma and Allergies in Childhood (ISAAC): rationale and methods
Eur Respir J
(1995) - et al.
Prevalence of asthma and allergic disorders among children in united Germany: a descriptive comparison
BMJ
(1992) - et al.
The international study of asthma and allergies in childhood (ISAAC): Phase Three rationale and methods
Int J Tuberc Lung Dis
(2005)
Fostering a spirit of critical thinking: the ISAAC story
Int J Tuberc Lung Dis
Worldwide variations in the prevalence of asthma symptoms: the International Study of Asthma and Allergies in Childhood (ISAAC)
Eur Respir J
The European Community Respiratory Health Survey
Eur Respir J
Comparison of asthma prevalence in the ISAAC and the ECRHS. ISAAC Steering Committee and the European Community Respiratory Health Survey. International Study of Asthma and Allergies in Childhood
Eur Respir J
Worldwide variation in prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema: ISAAC
Lancet
Global variation in the prevalence and severity of asthma symptoms: Phase Three of the International Study of Asthma and Allergies in Childhood (ISAAC)
Thorax
The strategy of preventive medicine
The relationship of per capita gross national product to the prevalence of symptoms of asthma and other atopic diseases in children (ISAAC). [see comments.]
Int J Epidemiol
Paracetamol sales and atopic disease in children and adults: an ecological analysis
Eur Respir J
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