Chronic obstructive pulmonary disease (COPD) is a major cause of ill health and death in adults and straddles the interface between primary and secondary care. There are at least 600 000 people in the UK with COPD, a prevalence of around 1%. The diagnosis is usually made relatively late in the natural history, after the age of 40, when symptoms start to appear.1 The prevalence rises to approximately 5% of men aged 65–74 and 10% of men older than 75. Historically, more men have been affected but women are rapidly catching up. Prevalence figures for COPD from Denmark, where women have smoked longer than men, show that the prevalence is now equal.2 COPD is the fifth most common cause of death in the UK, causing 5.4% of male and 3.2% of female deaths, and is a contributory factor on a further 4% of death certificates.3 In a typical district health authority with a population of 250 000, consultations with general practitioners (GPs) for COPD are similar in number to asthma but more patients with COPD will be admitted to hospital and they will stay in hospital for approximately three times as long . The mortality caused by COPD is at least 14 times that of asthma. It is reaching almost epidemic proportions in the Third World, principally as a result of increased tobacco consumption.4

Despite progress in reducing cigarette smoking, the mortality from COPD in the UK has remained constant for the last 20 years (fig 1). Figure 2illustrates some theoretical rates of decline of lung function (and hence disease progression). Approximately 20% of cigarette smokers are susceptible to progressive lung damage for reasons which remain unclear. The accelerated loss of lung function declines when they quit smoking, even in advanced disease. However, the absolute loss of …