鹿児島県における乳幼児死亡率の減少について

抄録

The secular changes and regional differences in perinatal, infant and early childhood mortality rates were studied for the period 1967 through 1986 using the health statistics issued by the Kagoshima prefectural government. The inter-relation of these mortality rates was also discussed. The following findings were made. 1) The infant mortality rate and early childhood mortality rates have generally declined progressively in the course of a 20-year period 1967 through 1986, the decrease was much more marked in infant mortality rate than in early childhood mortality rates and much greater in the first 15 years than afterward. The current low rates of infant mortality suggest that further decrease will be slower or difficult to achieve . Since 1980, in particular, the 1-year-old mortality rate has practically increased rather than stagnated. Then, a hypothesis was proposed that the increased rate in 1-year-old mortality was one of the causes of the decline in infant mortality rate by delaying deaths into the post-infant period. The late fetal death rate has also declined over the study period, the decrease was consistent with the pattern of infant mortality rate. 2) There were no marked differences between males and females for the changing patterns in infant and early childhood mortality rates. However, considerable differences in these mortality rates between male and female infants existed, in that male infants had consistently higher rates of mortality as compared with female infants . 3) Among 16 community-bases regional groups within the health center's jurisdiction, the income level was inversely correlated with both infant mortality rate and 1-4 year mortality rate. This correlation was significant for female infants but not for male infants. This fact raised a quetion whether the beneficial effects of urbanization in local communities on the infant and early childhood mortality rates were shown firstly among male infants. In contrast, fetal component of perinatal mortality was inversely correlated with female infant mortality rate but not with male infant mortality rate. The lower mortality rate reported for female infants may be partly attributed to the poor registration of infant deaths, since eraly neonatal deaths are sometimes reported as fetal death.