Trends in Emergency Department Visits and Hospitalizations for Acute Allergic Reactions and Anaphylaxis Among US Older Adults: 2006-2014

The US older adult population (age ≥65 years) is increasing and may be at increased risk for severe anaphylaxis. Little is known about the health care use for acute allergic reactions (AAR), including anaphylaxis, among older adults. To characterize trends in emergency department (ED) visits and hospitalizations for AAR and anaphylaxis among US older adults from 2006 to 2014 and examine factors associated with severe anaphylaxis. We performed cross-sectional analyses of trends in ED visits and hospitalizations among older adults using data from the Nationwide Emergency Department Sample and the National (Nationwide) Inpatient Sample in 2006 to 2014. We used International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes to identify visits for AAR, including anaphylaxis. Multivariable logistic regression modeling was used to identify factors associated with severe anaphylaxis (cardiac arrest, intubation, and death). In 2006 to 2014, older adults experienced approximately 1,019,967 AAR-related ED visits, 173,844 AAR-related hospitalizations, 93,795 anaphylaxis-related ED visits, and 72,677 anaphylaxis-related hospitalizations. Whereas AAR-related ED visit and hospitalization rates remained stable (P = .28 and .16, respectively), anaphylaxis-related ED visit and hospitalization rates increased significantly over time (37 visits/100,000 in 2006 to 51 in 2014, P < .001; and from 13 hospitalizations/100,000 in 2006 to 23 in 2014, P < .001), especially hospitalization rates for drug-related anaphylaxis (47 hospitalizations/100,000 in 2006 to 85 in 2014; P < .001). Risk factors for anaphylaxis-related death included older age and drug-related trigger. In a nationally representative sample of US older adults, the rate of anaphylaxis-related ED visits and hospitalizations increased over time. Drug-related triggers represented a substantial portion of increased health care use and are a growing risk in this vulnerable population.