To more precisely analyze the differences of prevalence of asthma betw
een countries and to try to explain these differences, the European Co
mmunity Respiratory Health Survey was conducted in 48 centres in 22 Eu
ropean and non-European countries. The common protocol comprised 2 pha
ses. Phase I was applied to a randomized sample of the general populat
ion of 3,000 subjects between the ages of 20 and 44 years in each cent
re. It consisted of a brief mail questionnaire composed of 7 questions
and 2 sub-questions concerning the prevalence of asthma and its sympt
oms during the previous year. Phase II then consisted of examining 600
subjects per centre, who had answered the questionnaire, and who subs
equently underwent skin tests, serum total and specific IgE assays, sp
irometry and a methacholine lest. Mar ked variations of the prevalence
of asthma and symptoms were observed between different countries. Nor
th-South and West-East gradient was observed in Europe. Variations of
the prevalence of allergic sensitization were also observed, which cou
ld partly explain the differences observed between some centres. The m
odalities of antiasthmatic treatment vary considerably from one countr
y to another. In France and Italy inhaled corticosteroids are rarely u
sed; inappropriate treatment of asthma was demonstrated in these 2 cou
ntries.