Better Understanding of Asthma and Other Chronic Diseases from Focusing on Communities

If you have a chronic disease of the airways such as asthma or rhinitis, the socioeconomic characteristics of your neighborhood may influence your health as much as your own personal socioeconomic status (SES), according to a recent study by researchers at the University of California San Francisco.

It is generally accepted that socioeconomic factors, such as income, education, and occupation, play a major role in determining health status and that these can be key aspects of the social environment, but there is no consensus on how best to measure and relate SES measures to health. SES can be assessed at the individual level through questionnaires, but it can also be characterized on a broader community scale using census data to ascertain patterns of income, education, employment rates, and other measures of wealth within an area or across population groups.

Thus, the question arises, does living in a disadvantaged area confer additional risk of poor health beyond low individual-level SES? According to lead study author Paul Blanc, professor of occupational and environmental medicine at UCSF, the results of this study suggest that the answer may be yes.

In this study, data describing the broader community did predict general and asthma-specific health status in adults with asthma and rhinitis. For example, the analysis of neighborhood variables showed that low mean income, low mean educational attainment and a low prevalence of managerial occupational status were associated with poorer health status in general and a lower quality of life for those with asthma and that this effect remained after taking into account personal SES. Blanc pointed out, however, that results were somewhat mixed in that individual SES factors were able to explain severity of asthma without an added eff ect of the neighborhood being observed.

The study, published in the January issue of the European Respiratory Journal, analyzed the respiratory health and SES levels of more than 400 adults with asthma and/or rhinitis living predominantly in northern California. Extensive interviews with subjects provided detailed individual information on SES, which was linked, using a process called geo-coding, to U.S. census data to elicit area-level SES measures. Given that area level SES factors appear to be independently related to certain health attributes, the question, then, is, what are the specific underlying mechanisms that account for this relationship? In addition to looking more closely at the general factors analyzed in this study, the researchers plan future study of the community physical environmental factors such as proximity to freeways, traffic density, and ambient pollutants that may aggravate airway responses and social environmental factors such as neighborhood support systems that might influence health status by affecting such things as individual stress levels and access to health care.

"It is clear," said Blanc, "that health status is the result of a complex set of relationships between the environment we live in and individual factors. The old adage 'no man is an island' is more true today than ever. The challenge is to find multiple analytical tools to gain a better understanding of specific causative factors around us so that truly effective interventions to improve health can be made."