Literature has suggested there are racial/ethnic differences in the rates of asthma in children. This study examined how multiple factors, such as family income level (poverty) and race/ethnicity, might interact to explain the reported differences.  Data from the National Health Interview Study (1997) used in this study considered information for the group of 14,244 children under age 18 years and who had ever been diagnosed with asthma by a doctor or health care provider according to the adult participating in the survey. Family income levels were grouped by percentage of Federal Poverty Level (FPL) for family size, i.e., less than 50% FPL (very poor), 50-100% FPL, 100-less than 200% FPL, or 200% or higher FPL.  This study considered children who were in non-Hispanic black, non-Hispanic white, Hispanic or “other” race/ethnic groups as reported by the adult. Other variables considered were parent education, low birth weight, child age and gender, environmental tobacco smoke exposure, having health insurance, health checkup status, family size, housing status (e.g., own or rent), and geographic location.

In this sample, asthma was more prevalent among non-Hispanic black children (13.6%) than non-Hispanic white (11.2%) or Hispanic (10.1%) children.  The rates of childhood asthma did not vary by family income level alone. Children who were covered by health insurance (88%) or who had received a checkup within the last year (73%) were more likely to have ever had diagnosed asthma.  However, there was a higher risk for diagnosed asthma among non-Hispanic black children in the lowest family income group. Other variables (health insurance, a check-up with the past year, environmental tobacco, rental housing, etc) did not alter the higher risk for asthma among the very poor non-Hispanic black children as compared to the very poor non-Hispanic white children.

This finding does not support literature that suggests that genetics or poverty alone is a primary “cause” of racial/ethnic differences in asthma rates. Rather than just noting racial/ethnic differences in asthma, studies should address reasons for the differences. Race/ethnicity as a social construct with health implications rather than just a genetic factor can be more relevant for understanding individual and environmental risks and developing clinical or community interventions.

(Smith L et al. Public Health Reports 2005;120:109-116) --J.O.