Changes in infant mortality rates among whites, coloureds and urban blacks in the RSA over the period 1970-1983.

Using national mortality statistics, we found that infant mortality rates (IMRs) declined among whites and coloureds in the RSA over the period 1970-1983, the decrease in coloured IMR being from 134,8 to 50,7/1 000 and that in white IMR from 21,6 to 12,6/1 000. The decrease in the IMR among coloureds was mainly due to the decline in post-neonatal mortality rates (PNMRs). Since post-neonatal deaths are generally due to gastro-enteritis, pneumonia, malnutrition and measles, the decline in mortality is probably due to a decrease in these causes. The decrease in early neonatal mortality made only a small contribution to the decline in the IMR among coloureds. In the case of whites the decrease in the IMR was largely due to the decline in the early neonatal mortality rate (ENMR); these deaths usually result from low birth weight, the respiratory distress syndrome, asphyxia and infections. The decline in the PNMR played a minor role. National IMRs for blacks are not reported annually, but IMRs can be calculated for the two census years 1970 and 1980 for blacks in 34 'selected' (urban) magisterial districts, and were 124,4 and 85,9/1 000 respectively. A valid IMR for 'rural' Transkei from a well-conducted epidemiological study was 130/1 000 in 1980. The components of the IMRs for blacks can only be determined for certain urban areas with large black populations such as Soweto (adjacent to Johannesburg), where the IMR fell from 81,4/1 000 in 1970 to 25,5/1 000 in 1983. The decline in the IMR was due to decreases in both the ENMR and the PNMR.(ABSTRACT TRUNCATED AT 250 WORDS)