The European Community Respiratory Heath Survey (ECRHS) was the first study
to assess the geographical variation in asthma and allergy in adults using
the same instruments and definitions. The database of the ECRHS includes i
nformation from similar to 140,000 individuals from 22 countries. The aim o
f this review is to summarize the results of the ECRHS to date.
The ECRHS has shown that there are large geographical differences in the pr
evalence of asthma, atopy and bronchial responsiveness, with high prevalenc
e rates in English speaking countries and low prevalence rates in the Medit
erranean region and Eastern Europe. Analyses of risk factors have highlight
ed the importance of occupational exposure for asthma in adulthood. The ass
ociation between sensitization to individual allergens and bronchial respon
siveness was strongest for indoor allergens (mite and cat). Analysis of tre
atment practices has confirmed that the treatment of asthma varies widely b
etween countries and that asthma is often undertreated.
In conclusion, the European Community Respiratory Health Survey has shown t
hat the prevalence of asthma varies widely. The fact that the geographical
pattern is consistent with the distribution of atopy and bronchial responsi
veness supports the conclusion that the geographical variations in the prev
alence of asthma are true and most likely due to environmental factors.