Abstract
The auther tried to evaluate the efficacy of mass examination of tuberculosis by decreasing rate of mortality rate from tuberculosis after the mass examination.
In Japan, nation-wide surveys of tuberculosis have been carried out 4 times every five years since 1953 and their rates of response were more than 98%; i. e., 99.3% in 1953, 98.9% in 1958 and 98.1% in 1963. The sample population were randomly selected from the stratified sampling unit areas. It was assumed that these sample populations have had one more chance of complete chest examination compared with the other persons in Japan.
The numbers of examinees were 50, 340 in 1953, 68, 269 in 1958 and 73, 399 in 1963. They were followed up one year and five years after the survey and the number of deaths were checked up.
The mortality ratios of the observed death to the expected were calculated. The mortality ratio was 0.70 (male 0.91 and female 0.44) in 1953 group, 0.76 (male 0.99and female 0.59) in 1958 group and 0.56 (male 0.57 and female 0.33) in 1963 group. The declining trend of mortality rate from tuberculosis was especially remarkable in female, but they were not satistically significant. During five years' observation, the mortality ratios were markedly decreased, namely, 0.31 in 1953 group, 0.68 in 1958group and 0.43 in 1963 group. These figures were statistically significant.
The above results suggest that there are still quite many und etected patients suffering from tuberculosis in Japan, and complete chest examination in such a group may cause reduction of mortality rate from tuberculosis in a few years.
