Dilatation and unfolding of the aorta in a Jamaican population.

In the year 1959-60 a team from the Medical Research Council's Pneumoconiosis Research Unit, in collaboration with the Ministry of Health, Jamaica, undertook a chest X-ray survey of a rural population in Jamaica with the primary objective of determining the prevalence of pulmonary tuberculosis (Miall and Rerrie, 1961). During the reading of the 70 mm. films, we were struck by the high prevalence of aortic and other cardiovascular abnormalities. As the survey had been carried out in a geographically defined population in which over 90 per cent of subjects were X-rayed, it was possible to compare the characteristics of those with radiologically detected cardiovascular abnormalities with those of an age and sex matched control group drawn by random methods from those subjects in the same population who were free of such abnormalities. This paper reports the results of this comparison. It is generally accepted that cardiovascular screening by mass radiography is a useful and practical procedure and the technique has been widely used, particularly in the United States (Thompson et al., 1961). Cochrane (1960) has reported the results of such a survey from Barbados, and Wattley (1960) from Trinidad. This is, as far as we know, the first time that an attempt has been made to use a control group to determine the wtiology of the abnormalities.