INTRODUCTION
Sickle cell disease (SCD), an inherited red blood cell disorder, affects approximately 100,000 individuals in the United States and 20 million worldwide, most of them of African ancestry.1 The condition is associated with lifelong fatigue, pain, infections, and diminished quality of life and survival, even in developed countries.2,3 Since the use of prophylactic antibiotics has reduced infection-related pediatric mortality from SCD, the focus has shifted to acute chest syndrome (ACS), which is currently the leading cause of death in children with SCD in high-income countries.4 ACS peaks between 2 and 4 years of age and is associated with significant morbidity (an average of 7 days hospital stay for each ACS admission), and even mortality. Approximately half of SCD patients develop at least one episode of ACS, and more than half of those have further recurrences.5 Repeated ACS is associated with increased lung injury and worsening restrictive pulmonary disease, with a dose-response effect.6,7 The risk of ACS recurrence is associated with clinical factors such as asthma, degree of anemia, and white blood count.8There is some evidence for environmental risks as well, such as tobacco smoke, high ozone levels, and low carbon monoxide exposure.9,10 The role of neighborhood characteristics in ACS incidence and recurrence has not been explored.
There is a wealth of literature that links socioeconomic conditions with child health outcomes.11-13 It is also known that African Americans families, even at higher levels of individual socioeconomic status, reside in disproportionately disadvantaged neighborhoods.14,15 Prior research indicates that the association of neighborhood-level socioeconomic deprivation with health varies by race and ethnicity.16,17 The mechanism of this relationship is unclear. It is possible that neighborhood racial composition moderates the health effects of neighborhood socioeconomic context. Seeking answers to some of these questions, the current study used area-level and clinical data to evaluate the association between neighborhood socioeconomic deprivation, neighborhood racial composition, and ACS incidence and recurrence in pediatric patients with SCD at a large SCD Center in the Southeastern United States.