[Epidemiologic study of pleural effusion in a district].

The pleural exudate complicates many different diseases. With the aim of facilitating differential diagnosis, the authors conducted a prospective epidemiological study of individual types of exudates. In a catchment area of 44,000 inhabitants, the authors, in cooperation with general practitioners and other physicians from the local hospital found clinical and roentgenological signs of effusion in 0.32% of the total population in one-year period. The exudate was diagnosed in 93 living and 49 dead patients, where it was undiagnosed during lifetime. The highest frequency was noted in the cardiac effusion (46%), malignant effusion (22%) and pneumonic exudate (17%). The next most frequent effusions were found in cases of embolism, hemothorax, inductive effusion in abdominal affections, effusion due to uremia, myxedema and rheumatoid exudates. These findings are comparable only with the estimated incidence of pleural effusion made in the USA accompanying the underlying condition and occurring in approximately 0.5% of the population. Accurate data drawn from an epidemiological field study have not been found either in Czechoslovak or world literature.