[The role of computed spirometry in the epidemiological study of respiratory symptoms]

An epidemiological study was made of a random representative sample of men and women aged 25-64 years. There were 167 men and 306 women. In order to compare forced expiration in persons with different combinations of respiratory symptoms, potentialities of the use of the forced midexpiratory flow 25-75% together with the FEVC, FEV1, FEV1/FEVC were examined. Among the flow parameters, the forced midexpiratory flow has the least variability, which permits using it for diagnosis of obstructive disorders of lung ventilatory function. The studies revealed qualitative peculiarities in the changes of the spirography readings among men and women. As compared to the examinees without respiratory symptoms, men with cough and sputum manifested a decrease in the parameters characteristic of mixed changes in lung ventilatory function with the predominance of obstructive alterations in chronic bronchitis. The degree of obstructive disorders was higher than in women showing the analogous symptoms. As compared to the examinees without respiratory symptoms, women suffering from chronic bronchitis were marked by lower values of the volumetric parameters, without any signs of forced expiration deceleration.