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.