[Start of PTB (Phthisis) mortality statistics in Japan (2)].
As mentioned in the previous report, PTB mortality by prefecture was printed in the "Statistics Annual", however, the population based on which the rate was calculated was not shown in the "Statistics Annual". In Japan, family register system was introduced in 1872, and every Japanese had to be registered at municipality where their family live. Based on this registry, statistics on registered population by sex and age, and by prefecture was available. In case when some family member(s) move to place other than registered place, he/she has to report to the local municipality in which they reside. When they move further to other place, the same procedure was required. Population based on this temporary registration system was named as A-type population, however, it did not show the population actually living in the municipality. Many persons newly register when they move in, however, forget to report to the previous residence when they move out. Overall numbers of move-in always larger than move-out. To adjust for this discrepancy and to estimate actually living population by each prefecture, the difference of move-in and move-out in a certain prefecture was multiplied by the ratio of total move-in and move-out in a certain prefecture and that of the whole country. Thus calculated population was designated as B-type population, and was proximate to actually living population in each prefecture. As B-type population was tabulated by sex in each prefecture, PTB mortality by sex could be calculated by using this B-type population, and the calculated figures were shown in Table 3 by sex for each prefecture. The correlation between PTB mortality by prefecture printed in the "Statistics Annual" and that calculated by using B-type population in 1886, 1892 and 1899 were shown in Fig. 4. Both coincide well nearly in all prefectures, except Tokyo and Hokkaido in 1886 and 1892, and in Tokyo in 1899. It was shown how difficult it was to estimate actually living population in an area where population move was very active, however, in general, in other prefectures both coincided well, and figures shown in Table 3 could be used to estimate PTB mortality in each prefecture by sex. Since 1899, ICD (International Classification of Diseases) was adopted in Japan as causes of death, and TB of all forms were divided into PTB, TB meningitis, intestinal TB and TB of other organs. As phthisis mortality was also available in 1899, correlation between PTB (Phthisis) mortality and that of TB of all forms was shown in Fig. 5 by age groups and by prefecture. The former was higher than the latter, and observing by age groups, correlation was not good in infants and elder population 60 years and over. In large cities like Tokyo and Oosaka, figures of the former were higher than the latter. It was indicated that it was not appropriate to combine and analyze the trend of PTB (Phthisis) mortality with the TB mortality statistics after 1899 adopting ICD.
Shimao
Tadao
T
Japan Anti-Tuberculosis Association, Tokyo, Japan.
D000367:Age Factors; D005260:Female; D049672:History, 19th Century; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D012042:Registries; D012737:Sex Factors; D014397:Tuberculosis, Pulmonary / Q000266:history* / Q000401:mortality