Sudden Infant Death Syndrome in Texas: a Geospatial Analysis

Purpose: to determine and explain the geospatial distribution of Sudden Infant Death Syndrome (SIDS) in Texas. The exact cause of SIDS is unknown, but it has been found to correspond to behaviors such as placing infants on their fronts to sleep, infants sleeping with soft bedding or toys in their crib, infants overheating, and exposure of infants to tobacco smoke. Geographic factors have by and large been de-emphasized in SIDS research, and as such represent a significant gap in the literature. However, factors such as temperature, demographics and socio-economic status may provide valuable insight into the underlying reasons behind the geographic distribution of SIDS in Texas. Methods: Standard Mortality Ratios (SMRs) were calculated for each county in order to categorize Texas counties as “high,” “average,” or “low” SIDS. The resulting data was examined in a Geographic Information System (GIS) in order to determine its spatial distribution. Demographic data was collected from the U.S. Census Bureau in order to descriptively analyze high and low SIDS counties, and T-tests were conducted in order to examine similarities and differences within and between these counties. Temperature data from the PRISM Climate Group was collected in order to examine the potential relationship between low temperature and SIDS deaths per 100,000. A linear model was created to describe this relationship. Results: 18 low and 54 high SIDS counties were identified by SMR. Low percentage of Hispanics and high percentage of vacant homes characterized the high SIDS group, while high percentage of Hispanics and low percentage of vacant homes characterized the low SIDS group. This difference was found to be significant at the p < 0.01 level. The temperature model was found to be significant at p < 0.05. This may be seen descriptively in that the high SIDS counties were clustered in the northeastern part of the state, where average temperatures are lower. Conclusions: the relationship between SIDS and low temperature may in part be explained by behavior. In cold weather, parents may be more likely to cover their infants with soft bedding, not realizing the danger. Additionally, certain elements of Hispanic culture might serve as a protective factor against SIDS. This may bear further investigation. Furthermore, vacancy rates have long been used as a proxy for urban decay, and might indicate poor housing conditions. This may act to create an environment which promotes SIDS.