Rheumatoid arthritis in males; an epidemiological study of a Welsh mining community.

Caplan (1953) suggested for the first time in Great Britain that some cases of rheumatoid arthritis amongst coalminers with pneumoconiosis can be recognized from a characteristic chest x-ray appearance. An epidemiological investigation of this new syndrome showed that this nodular lung fibrosis (Fig. 1, opposite), was associated with rheumatoid arthritis in more than 50 per cent. of cases; it also suggested that the prevalence of rheumatoid arthritis was increased amongst men with complicated pneumoconiosis (Miall and others, 1953). To determine whether the progressive massive fibrosis (P.M.F.) of complicated pneumoconiosis was an aetiological factor in the development of the arthritis, a survey of rheumatoid arthritis was undertaken in a Welsh mining valley where P.M.F. was known to be common amongst the miners. This paper describes further investigations into the relationship between rheumatoid arthritis and pulmonary disease. A previous x-ray survey of the Rhondda Fach had shown that the prevalence of massive fibrosis rose from over 10 per cent. in the 35-39 age group to over 20 per cent. in the 65 + age group (Cochrane and others, 1952), and the present survey was therefore carried out during the "follow-up" chest x-ray survey of the Rhondda Fach, undertaken by the M.R.C. Pneumoconiosis Research Unit and the Welsh Regional Hospital Board during the summer of 1953.