Epidemiological Studies on Bronchial Asthma in Japan

Abstract

Influence of bronchial asthma to the life in Japan was studied in the present paper, using five epidemiological approaches on the basis of the statistics of mortality and following results were obtained.
1) Rank of asthma in 15 leading causes of death.
As for the rank of causes of death in Japan, asthma was ranged between the 12th and 15th leading cause of death in recent 20 years from 1950 to 1969. Although asthma is not within the 10 leading causes of death, it holds still important position in total deaths.
2) Annual trend of the death rate from asthma.
During this twenty years, death rates from asthma for total age group and for the group at ages from 35 to 64 had been slightly decreasing in both sexes. On the contrary, the death rates from asthma for the groups at ages from 5 to 9, 10 to 14 and 15 to 19 had been increasing after 1959.
3) Annual trend of the rate of life lost from asthma.
During this twenty years, the rate of life lost from asthma had been decreasing year by year untill 1958. Since then, the rate of life lost had not been decreasing and it seems to reflect that the death rate from asthma for the younger age group had been increasing.
4) Prefectural difference of deaths from asthma.
The standard death ratio from asthma for each prefecture was calculated. Among the prefectures with high ratio, there were no significant differences of standard death ratio.
5) Asthma in life table.
In our clinic 3, 092 (1, 605 male, 1, 487 female) asthmatic patients had been treated in the period of 15 years from 1957 to 1971. Deaths of 52 male and 39 female patients were reported, in whom 18 male and 14 female patients died from asthmatic attack. Abridged life tables for these asthmatic patients and for all Japanese in 1968 were constructed. The expected survival (1x) of asthmatic patients per 100, 000 born alive was smaller than that of the general population after 10 years of age in both sexes. Life expectancy at birth of all asthmatic patients were 62.79 for male, 66.52 for female and these of asthmatics died from asthmatic attack were 56.55 for male and 57.91 for female. On the contrary, life expectancies of all Japanese in 1968 were 69.06 for male and 74.21 for female.
It is concluded that bronchial asthma is by no means a less important disease.