In their study, the researchers used the NICHD definition of SIDS: "the sudden death of an infant under one year of age, which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history." In all, the researchers examined the records of 260 infants from the ages of birth to one year who had died of SIDS in Chicago, Ill. between November 1993 and April 1996. Of these, 75 percent were African American, 13 percent were white, Hispanic and another 12 percent were white, non-Hispanic.
The study was conducted in Chicago because that city has a large African American community. The researchers compared information about each infant to information about a control infant -- a living infant of comparable age, who was from the same racial and or ethnic group, and who had a similar birth weight. All of the SIDS deaths were evaluated by the Cook County medical examiner's office; autopsies had been conducted to rule out other causes of death. Death scene investigators conducted interviews about circumstances surrounding the deaths. Roughly two weeks after the death, another interview was conducted with the infant's primary caregiver. This interview included questions not included on the death scene investigation, such as the infant's routine sleep patterns and access to health care.
The current study found that African Americans at that time were less likely than Caucasians to have been informed by health care personnel to avoid placing infants to sleep on the stomach. Most of the SIDS deaths occurred within the first four months of life, with most of these occurring between the first month and the third month. Consistent with other studies, most of the SIDS infants had died in the fall or winter -- 64 percent.