June 19, 2006

Infant mortality rate in Illinois decreased in 2004

 Chicago saw the lowest rate ever recorded

SPRINGFIELD, Ill. – Overall, the Illinois infant mortality rate decreased from 7.6 in 2003 to 7.3 infant deaths (less than one year of age) per 1,000 live births in 2004, making it the second lowest rate recorded in the state. The Illinois Center for Health Statistics, a division of the Illinois Department of Public Health (IDPH), has determined the final infant mortality rates by race category and age at death for all of Illinois, Chicago and Downstate (Illinois excluding Chicago) for 2004.

In 2004, the number of infant deaths in Illinois fell from 1,380 in 2003 to 1,317, a 4.6 percent decrease. During this same period, births also declined from 182,393 to 180,665, or a 0.9 percent decrease. Because the percentage of infant deaths fell faster than that for total births, the infant mortality rate decreased.

The overall infant mortality rate decrease in the state was due to a decrease during the neonatal period, 0-27 days. The neonatal mortality rate decreased from 5.2 in 2003 to 4.8 in 2004, the lowest ever recorded for Illinois. The postneonatal period (28-364 days) mortality rate increased from 2.3 in 2003 to 2.5 for 2004.

In Chicago, the neonatal and postneonatal mortality rate trends are similar to Illinois, but they show more improvement when compared to the state as a whole. For example, the decrease in the neonatal mortality rate was statistically significantly lower, from 6.5 in 2003 to 5.4 in 2004. The postneonatal mortality rate improved slightly from 3.1 to 3.0.

For Downstate, the overall infant mortality rate increased slightly from 6.8 in 2003 to 6.9 in 2004. The neonatal rate decreased, but the postneonatal rate increased.

By race category, the neonatal and postneonatal differences are repeated for the white category and the black category. The overall Illinois infant mortality rate for the black race category decreased from 15.6 in 2003 to 14.8 in 2004; the neonatal rate decreased from 9.9 to 8.9; and the postneonatal rate increased from 5.7 to 6.0.

In Chicago, the infant mortality rate declines were larger for the black category than the white category. The black category improved from 16.8 in 2003 to 14.1 in 2004, a statistically significant one-year decrease. Similarly, the neonatal rate decreased from 10.9 to 8.4, another statistically significant decrease. The postneonatal rate decreased slightly from 5.9 to 5.7.

For Downstate, the black category had increases in infant mortality rates for each age group: all infants, from 14.2 to 15.7; for neonatal, from 8.9 to 9.4; and for postneonatal, from 5.4 to 6.3.

To see the statistical data, click here.

Statistical Note

Statistical significance is based on a Chi square test of the difference in rates.

Race Categories

The race categories and their names are statistical constructs as defined by the federal Office of Management and Budget and are used in the collection and tabulation of Illinois vital event data. As such, they do not represent or necessarily equate to other race category classification systems or typologies.