Investigating the relationships among neighborhood factors and asthma control in African American children: A study protocol

Over 2 million children in the US have uncontrolled asthma. African American children are disproportionately affected with a risk of dying from asthma that is 7.6 times higher than non-Hispanic White children. Racial disparities in childhood asthma are partially attributed to differential exposures to poverty; unsafe and stressful neighborhoods; and unhealthy physical environments. This paper describes the protocol for an ongoing National Institutes of Health/National Institute of Nursing Research-funded descriptive, cross-sectional study to investigate two neighborhood factors that may influence children's asthma. Building on an existing dataset, this study examines associations among neighborhood greenspace, neighborhood safety, and level of asthma control while controlling for indoor asthma triggers in an urban sample of predominantly low-income, African American children with persistent asthma. Two new variables are added to the dataset: availability of neighborhood greenspace and neighborhood violent crime rate. Greenspace is being accessed using geographic information systems and measured using the normalized difference vegetation index. Neighborhood violent crime rate is calculated using geocoded, point locations for crimes downloaded from the city police department. It is hypothesized that parents living in unsafe neighborhoods are likely to keep their children indoors, thereby increasing their children's exposure to indoor asthma triggers and limiting the potential benefits of neighborhood greenspace. The biggest challenges thus far are related to limited variability in greenspace and violent crime rates. Progress to date and strategies to address these challenges are discussed. Results have the potential to inform interventions to improve asthmatic children's health and influence public health policy.