[Epidemiology of emphysema: analysis by autopsy in a series of elderly patients]

Epidemiologic studies indicate that various factors are involved in causing emphysema, although it is uncertain exactly how these factors contribute. Thus the correlation between pathological changes and clinical manifestations was studied. Results of autopsies done on 1940 men and 1791 women from 1978 to 1992 were analyzed retrospectively. Emphysema was graded, from macroscopic findings as follows: none (E 0), slight (E 1), moderate (E 2), and severe (E 3). The severity of anthracocsis was graded as well. Information regarding clinical diagnosis, smoking habits, and available spirometric data were obtained by reviewing the medical records. Prevalence of each grade of emphysema was: in men, E 0-48.6%, E 1-31.6%, E 2-15.8%, and E 3-4.0%; in women, E 0-81.6%, E 1-13.7%, E 2-3.7%, and E 3-0.8%. Pneumonia, lung cancer, and gastric ulcer were significant complications of emphysema, and may have contributed to the cause of death. The effects of various risk factors on the severity of emphysema were evaluated by multiple linear regression analysis. Male sex, age, smoking habit, and grade of the anthracosis were independent factors affecting the development of emphysema. Among them, anthracosis grade and smoking habit were found to be strongly contributing factors. Emphysema grade and FEV1% were significantly correlated, but several patients with moderate or severe emphysema did not show airflow obstruction. Therefore, receiver operating characteristic (ROC) curves were constructed to evaluate the value of the FEV1% in the diagnosis of emphysema. The diagnostic value of the FEV1% alone was low, so a multiple linear regression equation with three factors (sex, smoking habit, and FEV1%) was constructed.(ABSTRACT TRUNCATED AT 250 WORDS)