title: Asthma and the prospective risk of anaphylactic shock and other allergy diagnoses in a large integrated health care delivery system.
abstract: BACKGROUND
  The association between asthma and anaphylaxis remains poorly understood.
  
  
  OBJECTIVE
  To ascertain, in a managed care organization in northern California, the association of asthma and asthma severity with future risk of anaphylactic shock and other selected allergy diagnoses.
  
  
  METHODS
  Using electronic data and validated algorithms, we assembled a cohort of 526,406 patients who met the criteria for asthma between 1996 and 2006 and a referent cohort (with no utilization for asthma) individually matched on age, sex, and race/ethnicity. In each cohort, 54% of patients were female and 55% were white; their mean (SD) age was 24 (20) years. The main outcome measures were anaphylactic shock (caused by an adverse food reaction, caused by serum, or other/idiopathic), allergic urticaria, anaphylaxis after sting(s), and angioedema.
  
  
  RESULTS
  The incidence of anaphylactic shock was 109.0 per 100,000 person-years in the asthma cohort and 19.9 per 100,000 person-years in the referent cohort. After adjustment for age, sex, race/ethnicity, comorbidities, and immunotherapy, asthma was associated with a 5.2-fold (95% confidence interval, 4.7- to 5.6-fold) increased hazard of anaphylactic shock. Asthma was also significantly associated with an increased risk of the 3 selected allergy diagnoses, with hazard ratios of 1.4 to 1.9. A significant trend by severity of asthma was apparent for food-related and other/idiopathic anaphylactic shock and for anaphylaxis after sting(s).
  
  
  CONCLUSIONS
  In this insured population, asthma was prospectively associated with increased risk of anaphylactic shock and other allergy diagnoses. However, the effect of asthma severity was not consistent across outcome measures.
authors.affiliation: Division of Research, Kaiser Permanente, Oakland, California 94612, USA. cgi@dor.kaiser.org
authors.forename: Carlos
authors.initials: C
authors.lastname: Iribarren
authors.forename: Irina V
authors.initials: IV
authors.lastname: Tolstykh
authors.forename: Mary K
authors.initials: MK
authors.lastname: Miller
authors.forename: Mark D
authors.initials: MD
authors.lastname: Eisner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000707:Anaphylaxis / Q000453:epidemiology*; D000799:Angioedema / Q000453:epidemiology; D001249:Asthma / Q000453:epidemiology*; D002140:California / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology*; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012307:Risk Factors