<p>Asthma is a common and chronic inflammatory disorder of the airways, associated with pronounced health and economic consequences (Patel et al 1997). Following its development many people will face a significant alteration in lifestyle and deterioration in quality of life (Turner and Warwick 1989). In the UK, an estimated 1.9 million adults currently have asthma, which causes around 2,000 deaths per annum, despite modern therapeutic advances (National Asthma Audit 1997/1998).</p>