SOCIO-DEMOGRAPHIC DIFFERENCES IN PATIENTS HOSPITALIZED FOR ANAPHYLAXIS IN THE UNITED STATES

Introduction Anaphylactic shock is a life-threatening emergency that can lead to significant morbidity and mortality. Data from European studies have shown significant disparities in healthcare utilization for anaphylaxis, however there are limited studies describing the association between socioeconomic status and patient characteristics for hospitalizations related to anaphylaxis in the United States. Methods We utilized the National Inpatient Sample database years 2005-2014 to identify hospitalizations for anaphylactic shock (ICD-9 codes 995.0, 995.6x). The analysis focused on socio-demographic characteristics, medical comorbidities, and in-hospital death. We also performed an unadjusted analysis of trends in hospital costs and mortality rate. Results Between 2005 and 2014, anaphylaxis hospitalizations increased from 6,351 to 8,075. Of these, most were experienced by women (56.7%), whites (55.1%), paid for by private insurance (46.5%), and were more frequent in patients residing in areas with the highest income quartile (26.9%). Comorbidities frequently present in patients hospitalized for anaphylaxis were hypertension (36.6%), chronic pulmonary disease (28.8%), and electrolyte disorders (20.0%). Costs per hospitalization increased from $4,521 to $6,672 (2006-2015). The percentage of in hospital deaths rose from 0.86 (2006) to 0.93 (2015) and mean length of stay rose from 2.5 days (2005) to 2.7 days (2015). Conclusions There has been a modest increase in hospitalizations and in-hospital deaths from anaphylaxis in the last decade. In this study, more hospitalizations were associated with top-quartile income zip codes and private insurance. Further study is needed to determine whether these trends reflect disparities in access to healthcare or other factors that could affect health outcomes.