There is no widely applicable diagnostic test for asthma, and assessment of its frequency and determinants is based on responses to questionnaires, simple tests with imperfect sensitivity and specificity, and the outcome of medical care such as hospital attendances and drug prescriptions. Because asthma tends to remit and may relapse, it can be difficult to distinguish prevalent (or recurrent) disease from that which is truly incident. Most measures of frequency probably reflect prevalent asthma, i.e . that which is present at, or over, a particular time. Because the symptoms of asthma are not specific to the disease, they can be confused with those of other respiratory diseases, particularly, in later life, chronic obstructive pulmonary disease (COPD).
In the whole of Europe, about 30 million children and adults under 45 years of age have asthma. In most European countries, the prevalence and perhaps incidence of asthma increased substantially at some time between 1950 and 2000 but, at least in western Europe, the increase has levelled off in the past decade. Figure 1 shows the estimated current prevalence of asthma in European countries among adults aged between 18 and 44 years. The rates of disease tend to be higher in northern and western countries where the prevalence may be higher than 10%. Unlike childhood disease, adult asthma tends to be more common in females.
Asthma data available online
A public health summary of asthma provided by the European Commission with links to statistical data.
A summary of the epidemiology of severe asthma in Europe.
Website of the Global Initiative for Asthma (GINA).
An evidence-based review of the recognition, management and prevention of occupational asthma.
www.efanet.org/wp-content/documents/SASSevereAsthmaBackgrounder050307.pdf Briefing document on asthma from the European Federation of Allergy and Airways Diseases Patients Associations.