Future developments and research needs
Asthma is common in European adults and in many countries it is more common than it used to be. There remains a pressing need to understand its origins – in most cases in childhood – so that effective primary prevention can be devised. Where its causes are known – notably in occupationally induced disease – greater efforts need to be made in the regulation and control of causative exposures.
Propagation of good asthma care in Europe
Current medications are generally very effective but require appropriate availability and means of delivery. The establishment of national and international guidelines has been instrumental in improving the care of adults with asthma, through better education of medical practitioners, involvement of asthma-trained nurses and the implementation of standardised treatment regimens. In some countries, such as Finland and France, the active participation of government health departments has led to important improvements in asthma control with consequent reductions in morbidity, mortality and costs attributable to the disease, demonstrating that focused, national programmes can work and are probably cost-effective. In any such programme, it would be important to address three particular issues that contribute to the continuing burden of asthma. 1) Are all patients who need treatment receiving and taking adequate controller medication? 2) Are patients with persistent uncontrolled asthma being adequately monitored and investigated as to the cause of the poor control? 3) Are the co-existing factors associated with asthma being treated or addressed, such as cigarette smoking or secondary smoke exposure, allergies, sino-rhinitis and obesity?
Difficult-to-control severe asthma
Difficult-to-control severe asthma can be subdivided into: 1) untreated severe asthma caused by poor access to medical care and asthma therapies; 2) difficult-to-treat, severe asthma resulting from poor management or poor patient adherence to treatment; and 3) treatment-resistant asthma for which control is not achieved despite the highest level of recommended treatment (refractory asthma and corticosteroid-resistant asthma) or for which control can be maintained only with the highest level of recommended treatment with a risk of side-effects.
New therapeutic approaches are needed for the category of patients with treatment-resistant asthma. First, we need a better understanding of its pathophysiology and its relation to the various phenotypes of adult asthma with respect to clinical presentation, functional abnormalities and features of airway inflammation and remodelling. Several distinguishable phenotypes of adult asthma have been described: for example, those with the most severe disease, requiring treatment with two or more controller medications, have a later age of onset, the greatest degree of airflow obstruction and the poorest bronchodilator response. Another characteristic of some types of severe asthma is the presence of a persistently high number of eosinophils in the sputum, despite high-intensity treatment. This type of asthma would be expected to respond to novel therapies targeting eosinophils, such as anti-IL-5 antibody treatments. Thus, the importance of defining phenotypes lies in matching them with novel, specific therapies that would benefit the individual patient.