Tools to assess (and achieve?) long-term asthma control

Abstract

Assessment tools are needed to monitor asthma control and to detect exacerbations before the alteration of functional parameters and the occurrence of symptoms. The ability to effectively monitor asthma control would enable clinicians to increase corticosteroid dose or to stop corticosteroid tapering before symptoms occur. As a few severe exacerbations are expected per year in treated patients, these tools must be suitable for long-term use. They must also be reproducible, acceptable to patients and be non-invasive. Tools currently available to assess asthma control include assessment of: clinical parameters (e.g. nocturnal awakenings; bronchodilator intake; symptom scores); lung function (e.g. peak expiratory flow and forced expiratory volume in 1 s); subjective parameters of asthma control (e.g. asthma control questionnaire (ACQ)); bronchial hyper-responsiveness; eosinophilia in induced sputum; and exhaled nitric oxide (NO) concentration. Clinical symptoms, lung function and the ACQ have proved to be inadequate markers of asthma control, as changes in these parameters occur at the same time as symptom manifestation. By contrast, sputum eosinophilia and exhaled NO concentrations are truly predictive of asthma exacerbations; monitoring these parameters are useful in preventing exacerbations from occurring in the first instance. They also assess, and help to achieve asthma control in the long term.