Time to rethink the inner-city asthma epidemic?

Published Online: January 20, 2015

Although it has long been thought that children living in poor urban areas (“the inner-city”) have higher rates of asthma than other children, the rate of asthma in these and other areas has been poorly described. Even more important, whether differences in rates are due to simply living in the inner-city or are instead related to the demographic characteristics of children living in these areas (characteristics such as race/ethnicity and poverty) is not clear. Now, in a study recently published in The Journal of Allergy and Clinical Immunology (JACI), C. Keet and colleagues use a very large national study to estimate the rate of asthma among children living in inner-city and non-inner city areas throughout the US, and to examine whether demographic features or geography are more important predictors of high asthma rates.

In this study, the authors used the National Health Interview Survey, a nationally representative survey that is designed to estimate asthma prevalence in the US. They linked the survey to data from the CDC and the US Census in order to categorize children as living in poor or non-poor urban, suburban, medium metro or small metro/rural areas. The authors then further analyzed asthma rates by race/ethnicity, family income, and region of the country. Overall, 23,065 children aged 6-17, and living in 5,853 different census tracts, were included.

The prevalence of asthma was higher in inner-city (12.9%) than in non-inner-city areas (10.6%), but this difference was no longer significant when race/ethnicity, age, sex, and region were accounted for, indicating that it is these other demographic factors—rather than simply living in the inner-city—that explain the higher prevalence of asthma in inner-cities. Consistent with the findings that living in the inner-city does not increase the risk of asthma, certain poor, non-urban areas also had very high rates of asthma. When income was accounted for, Black race, Puerto Rican ethnicity, and lower household income—but not residence in either poor or urban areas— were the most important risk factors for asthma.

These findings highlight the need to understand which populations are most at risk for developing asthma in order to develop the public health measures most effective for preventing it. Although this study shows that living in an urban area may not be an important risk factor for the development of asthma, further research is needed to determine whether living in an urban area may put children with asthma at higher risk of asthma exacerbations.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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