International Study of Asthma and Allergies in Childhood
| Project leader | Stephan Weiland † is co-initiator, member of the Executive of the Steering Committee and coordinator of Phase II |
The International Study of Asthma and Allergies in Childhood (ISAAC) was developed to exploit the potential of epidemiology to investigate the causes of asthma and allergies in children through standardised methodology and international collaboration.
The aims of the ISAAC project are:
1. to describe the prevalence and severity of asthma, allergic rhinitis and atopic dermatitis in children in different study centres and to make comparisons between data from different study centres;
2. to establish baseline values for estimating temporal changes in the prevalence and severity of these diseases;
3. to provide a framework for further aetiological research into the importance of lifestyle, environment, genetics and medical care in the manifestation of these diseases.
The global study will be conducted in three phases. Phase I was developed to determine the prevalence and severity of asthma, allergic rhinitis and atopic dermatitis in children in as many defined populations as possible using simple but valid methods.
The aim of Phase II is to confirm the results of Phase I in selected populations with additional objective parameters (including lung function, atopic sensitisation) and to gain more precise knowledge of the risk factors for these diseases.
Phase III repeats the prevalence studies from Phase I after at least five years in order to quantify the changes over time in the prevalence and severity of asthma and allergies in children worldwide.
The results of the Phase I studies, which were conducted in a standardised manner in 155 study centres on all five continents in a total of 463,801 children aged 13-14 years and 304,796 children aged 6-7 years, show great variability in the prevalence of the disease. The centres with the highest asthma rates were in the UK, New Zealand, Australia, Canada and the USA, while the lowest rates were found in China, Greece, Albania and Indonesia. Differences in living and environmental conditions play an important role in the large fluctuations in the incidence of the disease. These are currently being investigated in more detail in so-called ecological analyses and in phase II of the ISAAC project.