Violent crime and socioeconomic deprivation in shaping asthma-related pollution susceptibility: a case-crossover design

Abstract

Background: The objective of this study was to quantify and compare the relative influence of community violent crime and socioeconomic deprivation in modifying associations between ozone and emergency department (ED) visits for asthma among children.

Methods: We used a spatiotemporal case-crossover analysis for all New York City EDs for the months May-September from 2005 to 2011 from a statewide administrative ED dataset. The data included 11 719 asthmatic children aged 5-18 years, and the main outcome measure was percentage of excess risk of asthma ED visit based on Cox regression analysis.

Results: Stronger ozone-asthma associations were observed for both elevated crime and deprivation (eg, on lag day 2, we found 20.0% (95% CI 10.2% to 30.6 %) and 21.0% (10.5% to 32.5%) increased risk per 10 ppb ozone, for communities in the highest vs lowest quartiles of violent crime and deprivation, respectively). However, in varied models accounting for both modifiers, only violence retained significance.

Conclusions: The results suggest stronger spatiotemporal ozone-asthma associations in communities of higher violent crime or deprivation. Notably, violence was the more consistent and significant modifier, potentially mediating a substantial portion of socioeconomic position-related susceptibility.

Keywords: air pollution; asthma; paediatric; poverty; violence.

Figure 1

Violent crime and socioeconomic deprivation by childhood asthma emergency department visits in NYC, June–August, 2005–2011. Dots represent cases colour-coded by low crime/low deprivation, low crime/high deprivation, high crime/low deprivation and high crime/high deprivation. Different colour dots within the same police precinct boundary occur because cases represent 2005–2011 and crime and deprivation Z-scores changed over this period. The inset (previously published in Shmool et al 27) includes the near residence to citywide ozone ratios for cases (n=11 719; range, 0.57–1.16).

Figure 2

Associations between day-specific and residence-specific ozone and risk of emergency department (ED) visit for asthma, by quartile of community socioeconomic deprivation, 2005–2011, in NYC. X-axis includes lag days 0–6. Y-axis is percentage of excess risk per 10 ppb increase in ozone exposure. Shapes represent quartiles of community socioeconomic deprivation.

Figure 3

Associations between day-specific and residence-specific ozone and risk of emergency department (ED) visit for asthma, by quartile of community violent crime, 2005–2011, in NYC. X-axis includes lag days 0–6. Y-axis is percentage of excess risk per 10 ppb increase in ozone. Shapes represent quartiles of violent crime.

Figure 4

Ozone by median-dichotomised violent crime and socioeconomic deprivation interaction on childhood asthma emergency department (ED) visit risk, 2005–2011, in NYC. X-axis includes lag days 0–6. Y-axis is percentage of excess risk per 10 ppb increase in ozone exposure. Shapes represent four categories cross-stratified by median-dichotomised violent crime and socioeconomic deprivation (low crime/low deprivation; low/high; high/low; high/high).