[Prevalence of premorbid forms and chronic nonspecific lung diseases: study based on special examination of the population of 3 administrative districts of Leningrad].

For the first time ever, a familial study of 15,319 residents of three administrative districts in Leningrad has provided data on the prevalence of premorbid pulmonary conditions (157%) and chronic nonspecific pulmonary disease (118%). For Leningraders, average risk of premorbid conditions transforming into clinical ones was about 40%, which is the most objective criterion of the efficiency of bronchopulmonary disease prevention programs in large cities. In addition, data on the pattern of transformation of premorbid conditions into chronic nonspecific pulmonary disease are presented with respect to sex and age.