Characteristics of coalminers who have suffered excessive loss of lung function over 10 years

From a longitudinal study of respiratory health of coalminers, we have selected 29 smokers and 12 non-smokers with the greatest decline in FEV1 over a ten year period and have compared them with 29 smokers and 14 non-smokers with the least decline. In order to identify syndromes associated with rapid decline in FEV1, we made a clinical and physiological examination of these men five years after the end of the ten year period of measured FEV1 decline. There was no substantial difference in mean lung function between rapid and slow decliners at the time of examination. However, the rapid decliners as a group had an excess of respiratory symptoms, a significantly lower mid-expiratory flow rate and an excess of early and mid-inspiratory crackles on auscultation. Lung function was only abnormal by conventional standards in one third of the smoking rapid decliners. These men had either airflow obstruction (accompanied in three cases by evidence of emphysema) or a concentric reduction of both FEV1 and FVC. There was no excess of atopy nor of history of childhood respiratory illness in rapid decliners. We conclude that it is likely to be difficult to detect the rapid decliners among working men on the basis of a single examination and that at present detection must depend on serial measurements of FEV1.