New York State Cases Of Anaphylaxis In Elderly Patients From 2000 To 2010.

C. Patel
M. Haque
O. Waqar
M. Kline, Northwell Health
A. Jongco, Zucker School of Medicine at Hofstra/Northwell


There is limited information on the impact of anaphylaxis, a severe, potentially life-threatening allergic reaction, in the elderly. Elucidate the frequency of anaphylaxis and the demographic characteristics of elderly patients admitted to New York (NY) hospitals from 2000-2010. A retrospective analysis of hospitalized patients aged ≥65 years in NY from 2000-2010 was conducted using the Statewide Planning and Research Cooperative System (SPARCS), a statewide administrative database. Cases were identified using anaphylaxis ICD-9 codes or an ICD-9-based diagnostic algorithm incorporating the National Institutes of Allergy and Infectious Disease (NIAID) diagnostic criteria. The chi-square test was used to measure the association between demographic characteristics and group membership. Regression was used to model group and age as a function of hospital rates. 3,673 hospitalizations were analyzed. Anaphylaxis ICD-9 codes identified 1790 (48.7%) cases, the algorithms identified 1701 (46.3.%) and 182 (5.0%) were identified by both. Hospitalization rates increased significantly during this period (p<0.0001). Females comprised 61.5% and whites comprised 69.8% of the sample. Distribution by age differed by ascertainment method (ICD-9 vs. Algorithm) among the Early-old (age 65-74) 53.8% vs. 41.8%, respectively, and among the Late-old (age ≥85) 11.2% vs. 19.3%, respectively. Hospitalization rates and anaphylaxis cases increased during the study period among the hospitalized elderly population of NY. Relying on anaphylaxis ICD-9 codes alone missed about half of possible cases. The identification, and possibly, impact of anaphylaxis among the elderly may differ depending on age, race, payor, NY county, and disposition.