The influence of socioeconomic status on the risk of Haemophilus influenzae type b disease.

The importance of socioeconomic status (SES) is examined as a risk factor for invasive disease caused by Haemophilus influenzae type b (Hib). A model of Hib disease is used to explore the susceptibility and environmental factors, which mediate the influence of SES on the risk of Hib disease. The study estimates the relative risk of disease associated with SES using data from a population-based case control study of Hib infections in Dallas County, TX children aged 0-59 months. Data, collected for 268 culture proven cases of Hib disease and 536 age matched controls, are analyzed by conditional logistic regression. Among unvaccinated children 0-59 months of age, low SES increases the risk of Hib disease two-fold. Among vaccine eligible children (18-59 months), low and medium SES is associated with a three to four-fold increase in the risk of disease. Among unvaccinated children, the factors mediating the influence of SES are breastfeeding, smoking by household members, and living in crowded household with other young children. Among vaccine eligible children, the difference in the risk of disease between high and medium SES children is eliminated and the difference between high and low SES children greatly diminished after the effect of Hib vaccine is taken into account. An important factor suppressing the influence of SES is day care. Adjusting for the effect of day care increases the net effect of SES. Low SES households and day care settings appear to be two different environments raising the risk of Hib disease, and ones affecting distinct groups of children. Unlike studies of adult mortality and mobility, which emphasize the sharply differing life situations and states of health associated with varying levels of SES, the study of SES and Hib disease show how both low and higher SES children were exposed to conditions increasing the risk of infectious disease. Given the expanding role of day care for children of all levels of SES, policies limiting the spread of infectious disease among children in day care have the potential of improving the health of both poor and more affluent children.PhDDemographyHealth and Environmental SciencesPublic healthPublic policySocial SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/131504/2/9909961.pd