International variations in asthma treatment compliance: the results of the European Community Respiratory Health Survey (ECRHS).

Noncompliance to medication is a major barrier to effective asthma management. Its real extent and geographical variation throughout the world are not yet known. The data on compliance, collected in the framework of the European Community Respiratory Health Survey (ECRHS) on 1771 subjects (aged 20-44 yrs) with current asthma identified in 14 countries, offer a unique opportunity to assess the extent of noncompliance and its variation across countries. The median percentage of current asthmatics who had received a medical prescription at least once was 95%. The compliance of those patients who had received a medical prescription was found to be low in all countries (median 67%) but with wide variations, the rate ranging from 40% (USA) to 78% (Iceland). During exacerbations patients' rate of compliance increased to 72%. Age was the only variable which influenced compliance to treatment. A significant, although weak, negative correlation was found between patients' compliance and rate of hospital casualty department or emergency room admissions. This study documents that compliance to the treatment of asthma is poor worldwide and that there are large variations between countries. These results emphasize the necessity for further efforts to improve patients' education and to promulgate the international guidelines.