title: Explaining Racial Disparities in Child Asthma Readmission Using a Causal Inference Approach.
abstract: Childhood asthma is characterized by disparities in the experience of morbidity, including the risk for readmission to the hospital after an initial hospitalization. African American children have been shown to have more than 2 times the hazard of readmission when compared with their white counterparts.
  
  
  
  To explain why African American children are at greater risk for asthma-related readmissions than white children.
  
  
  
  This study was completed as part of the Greater Cincinnati Asthma Risks Study, a population-based, prospective, observational cohort. From August 2010 to October 2011, it enrolled 695 children, aged 1 to 16 years, admitted for asthma or wheezing who identified as African American (n = 441) or white (n = 254) in an inpatient setting of an urban, tertiary care children's hospital.
  
  
  
  The main outcome was time to asthma-related readmission and race was the predictor. Biologic, environmental, disease management, access, and socioeconomic hardship variables were measured; their roles in understanding racial readmission disparities were conceptualized using a directed acyclic graphic. Inverse probability of treatment weighting balanced African American and white children with respect to key measured variables. Racial differences in readmission hazard were assessed using weighted Cox proportional hazards regression and Kaplan-Meier curves.
  
  
  
  The sample was 65% male (n = 450), and the median age was 5.4 years. African American children were 2.26 times more likely to be readmitted than white children (95% CI, 1.56-3.26). African American children significantly differed with respect to nearly every measured biologic, environmental, disease management, access, and socioeconomic hardship variable. Socioeconomic hardship variables explained 53% of the observed disparity (hazard ratio, 1.47; 95% CI, 1.05-2.05). The addition of biologic, environmental, disease management, and access variables resulted in 80% of the readmission disparity being explained. The difference between African American and white children with respect to readmission hazard no longer reached the level of significance (hazard ratio, 1.18; 95% CI, 0.87-1.60; Cox P = .30 and log-rank P = .39).
  
  
  
  A total of 80% of the observed readmission disparity between African American and white children could be explained after statistically balancing available biologic, environmental, disease management, access to care, and socioeconomic and hardship variables across racial groups. Such a comprehensive, well-framed approach to exposures that are associated with morbidity is critical as we attempt to better understand and lessen persistent child asthma disparities.
authors.affiliation: Division of General and Community Pediatrics, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio2Division of Hospital Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohi.
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Beck
authors.affiliation: Division of Biostatistics and Epidemiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Bin
authors.initials: B
authors.lastname: Huang
authors.affiliation: Division of Hospital Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Auger
authors.affiliation: Division of Biostatistics and Epidemiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Ryan
authors.affiliation: Division of Biostatistics and Epidemiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: Division of General and Community Pediatrics, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Kahn
mesh_terms: D000293:Adolescent; D001741:Black or African American; D001249:Asthma / Q000208:ethnology* / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006297:Health Services Accessibility / Q000706:statistics & numerical data; D054624:Health Status Disparities; D054625:Healthcare Disparities / Q000208:ethnology* / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D008297:Male; D009820:Ohio; D010359:Patient Readmission / Q000706:statistics & numerical data*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012959:Socioeconomic Factors; D044465:White People