Why is chest disease so common in South Wales? Smoking, social class, and lung function: a survey of elderly men in two areas.

A respiratory survey was conducted in two British towns, one with a high mortality (Caerphilly) and one with a low mortality (Bath) from respiratory disease. A total of 513 men aged 65-74 years were seen. The Caerphilly men had poorer lung function than the Bath men; the overall difference in FEV1 and FVC for men aged 70 and 1.68m tall was 0.16 1 and 0.17 1 respectively. These differences appeared to be largely due to the greater tendency of the Caerphilly men to smoke and to an effect related to social class. Respiratory symptoms were also more common in Caerphilly, principally because of the effects of smoking and occupational group, although when these factors were allowed for there was still a significantly greater prevalence of breathless wheezing in Caerphilly.