Infant Mortality: SIDS: A Descriptive Analysis
Andrene Gray
Advisor: R. Leonard Vance, Ph.D., J.D., C.I.H.
Preceptor: Elizabeth P. Eustis-Turf, Ph.D.
OBJECTIVE: Infant mortality is strongly influenced by genetic endowment, maternal health, and intrauterine and postnatal environment, which affect the survival rate of an infant during the first years of life. Sudden Infant Death Syndrome (SIDS) continues to be the leading cause of infant deaths beyond the neonatal period (28 –365 days), accounting for approximately four to six thousand deaths per year. Although this syndrome has been studied extensively, its etiology remains unclear. Racial disparity is still a persistent and recurring theme in the etiology and prevalence of SIDS, with African American and American Indian infants 2-3 times more likely to die of SIDS than whites. This race specificity of SIDS reflects the influential role of selected sociodemographic characteristics, maternal health, knowledge and practices, and the accessibility to quality health care on the prevalence of risk factors. The objective of this study is to analyze the incidence of SIDS in all infant deaths in Virginia from 1995 to 2000, to note its frequency and which sociodemographic and pregnancy characteristics are associated with this syndrome.
METHODS: Linked birth/infant death data set (N= 4383) under one year of age who died in Virginia was obtained from the Office of Vital Statistics of the Virginia Department of Health for 1995 to2000. Sociodemographic and pregnancy characteristics on linked data set were used to analyze the frequency of SIDS deaths and any similarities and differences with non-SIDS deaths. SPSS and Epi 6(Epitable, Epicalc) were used to analyze the data to note infant deaths and race-specific rates, frequency distribution (PMR), Chi-square test with associated P-values, and POR with 95% Confidence Intervals. Logistic Regression was used to identify which sociodemographic and pregnancy characteristics were associated with SIDS deaths as opposed to non-SIDS deaths.
RESULTS: Total infant mortality rates are on the decline in Virginia. In 1995, the rate was 8.09 per 1,000 (N=743) and it dropped to 7.15 per 1,000 (N=707) in 2000. Even though whites had the largest proportion of SIDS deaths from 1995 to 2000, when population was adjusted for, blacks had the highest rates per 1,000 (0.75 vs. 1.33, 0.65 vs. 0.82, 0.62 vs. 1.00, 0.64 vs. 1.69, 0.54 vs. 0.77, 0.42 vs. 1.26, respectively). The most significant differences between SIDS and non-SIDS deaths were birth weight, gestational age, age at death, prenatal visits, weight gained during pregnancy, and tobacco use, with P-values <0.05. Logistic regression analysis showed that the age of infant death (2 to 3 months), cigarette smoking (>a pack), birth order (2 or 3), sex of infant (male), and younger maternal age were associated with SIDS. Chi-square for trend for maternal cigarette smoking noted a dose response relationship.
CONCLUSION: In Virginia from 1995 to 2000, the SIDS rates were highest for blacks. Sociodemographic and pregnancy characteristics associated with SIDS were sex (male), age of infant death (2-3 months), birth order, maternal age, and exposure to maternal smoking. This study was helpful in describing the SIDS population and what sociodemographic and pregnancy characteristics can be associated with SIDS. Because the first year of life is critical, it is of the utmost importance to identify at-risk groups and populations, along with risk factors and behaviors that are associated with a disease. Through epidemiological studies and analysis, risk factors or behaviors can be identified and preventive strategies can be implemented specific to the target groups and target behaviors for intervention and education by health care and public health professionals.
