Children’s asthma hospitalizations and relative risk due to nitrogen dioxide (NO2): Effect modification by race, ethnicity, and insurance status

Abstract

Background This study explores the role of race, ethnicity, and insurance-status in modifying the effects of air pollution on children’s asthma hospitalizations in Phoenix, Arizona (US) between 2001 and 2003. While controlling for weather, interactions between nitrous dioxide (NO2) and race, ethnicity, and insurance-status are used to predict relative risk for subgroups of children. Methods The generalized logit regression model for nominal categorical data within a multinomial likelihood framework was used. This model is specifically suited to small counts and the reporting of 95% confidence intervals for the odds–ratio of hospital admission for one group as compared to another. The odds ratio is known to approximate relative risk for rare events. Results Several significant findings were found for race, ethnicity, and insurance-status as modulators for the effect of NO2 on children’s risk for asthma hospitalization: (1) Children without insurance have 1.4 (95% CI: 1.1–1.8) times higher risk of asthma admissions than those with private insurance at exceedances of .02 parts per million (ppm) of NO2 above the seasonal mean; the same finding holds for children without insurance as compared to those with Medicaid; (2) Black children have 2.1 (95% CI: 1.3 –3.3) times higher risk of hospitalization than Hispanic children at seasonal mean NO2 levels, but this disproportionate risk shrinks to 1.7 with exceedances of .02 ppm of NO2 above the seasonal mean. Specific to finding (1) among those children without health insurance, Hispanic children have 2.1 (95% CI: 1.1–3.8) times higher risk of hospitalization than white children. Among all Hispanic children, those without health insurance have 1.9 (95% CI: 1.3–3.0) times greater risk than those with private insurance; the same finding holds for Hispanic children without insurance as compared to Hispanic children with Medicaid. Specific to finding (2), among children with private insurance, the disproportionate risk of black children as compared to Hispanic children is magnified by a factor of 1.3 (95% CI: 1.0–1.8) for exceedances of .02 ppm of NO2 above the seasonal mean. Conclusions Although we cannot confirm a cause-effect relationship, this analysis suggests that increasing insurance enrollment for all children, and specifically Hispanic children, may reduce their disproportionate risk from exceedances of air pollution. There are few black children in Phoenix, so further studies are needed to investigate the increasing risk of black children with private insurance as compared to Hispanics at exceedances of NO2.

Evaluation of individual and area-level factors as modifiers of the association between warm-season temperature and pediatric asthma morbidity in Atlanta, GA

“…Interestingly, similar findings were reported by Grineski et al in a comprehensive study examining effect modification of nitrogen dioxide (NO 2 )-related asthma exacerbation by insurance status and race (Grineski et al, 2010). In that study, Grineski et al disaggregated insurance status into three categories: private insurance, Medicaid, and no insurance and reported significantly lower relative risks to NO 2 -related asthma among children on Medicaid compared to children on private insurance (Grineski et al, 2010), and significantly greater relative risks to NO 2 -related asthma among uninsured children compared to those using Medicaid or private insurance.…”

“…In that study, Grineski et al disaggregated insurance status into three categories: private insurance, Medicaid, and no insurance and reported significantly lower relative risks to NO 2 -related asthma among children on Medicaid compared to children on private insurance (Grineski et al, 2010), and significantly greater relative risks to NO 2 -related asthma among uninsured children compared to those using Medicaid or private insurance. In light of the findings by Grineski et al, our results may have been more interpretable had we been able to disaggregate our ED data further, exploring associations among the uninsured population.…”

School-based exposure to hazardous air pollutants and grade point average: A multi-level study

“…First, a hypothesis forwarded in the environmental justice literature is that poorer air quality is linked to increases in respiratory illnesses, which results in school absenteeism, and diminished academic performance (Pastor et al 2002, 2004, 2006; Lucier et al, 2011). In support of this hypothesis are those studies linking exposure to air pollution to increases in respiratory infections and asthma (Belleudi et al 2010; Grineski et al 2010; Peden 2015; Ghosh et al, 2016) and those associating exposure to air pollution with increased absenteeism (Currie 2009; Gilliland et al 2001). However, the link between asthma and poorer school performance is tenuous.…”

The asthma prediction rule to decrease hospitalizations for children with asthma

“…[65] The medications or interventions available in an outpatient context vary widely, based on patient factors (e.g., access to care), hospital characteristics (e.g., asthma education provided) and community characteristics (e.g., air quality). [66–68]…”