Housing conditions and the quality of children at birth.

Low birth weight (less than 2,501 grams at birth) rates were computed for the 338 health areas of New York City for three time periods: 1969-1971, 1979-1981, and 1985-19. Frequency distributions of the 338 health areas were developed according to the percent of babies with birth weights less than 2,501 grams for each of the periods indicated above. Comparison of the 1970 and 1980 distributions indicates a decrease in low birth weight rates, but an increase in both tails of the 1980 distribution, resulting in greater variability in 1980 rates. This polarization reveals that some areas of New York City had achieved very low rates while other areas had increased to exceptionally high rates. The distribution for 1986 (1985-1987) indicates a continuation of rate shifts, particularly in the low rate tail where, in comparison with 1980, 19 additional health area populations had rates of low birth weight less than 0.05. With 1970 as a reference point, 71 additional health area populations had achieved rates less than 0.05 by 1986. In contrast, the high tail for 1986 does not shift and is very similar to that of 1980. As previously noted, the shift in rate values in the high tail from 1970 to 1980 is not in the expected direction and contributes to the polarization of health status in New York City populations by contributions of newborns. Low birth weight values for 1986 stabilize this shift in the "wrong" direction. The range of minimum and maximum values, which increased from 0.144 to 0.190 to 0.226 for 1970, 1980, and 1986 respectively, document the change in degree of polarization. Health areas in the high low birth weight tail experienced the greatest amount of housing destruction and community devastation between 1970 and 1980.