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