ABSTRACT
The morbidity associated with respiratory disease is also considerable and the World Health Organization (WHO) has predicted that chronic obstructive pulmonary disease (COPD), for example, will move from being the twelfth commonest cause of disability-adjusted life years lost in 1990, to being the fifth commonest cause (after ischaemic heart disease, depression, road traffic crashes, and cardiovascular disease) by 2020. 2,800,000 hospital bed-days are used every year in the UK for COPD and chest infections alone, and respiratory diseases cost the health service more than any other disease area.
