title: Geographic variability of childhood food allergy in the United States.
abstract: OBJECTIVE
  The aim of this study was to describe the distribution of childhood food allergy in the United States.
  
  
  METHODS
  A randomized survey was administered electronically from June 2009 to February 2010 to adults in US households with at least 1 child younger than 18 years. Data were analyzed as weighted proportions to estimate prevalence and severity of food allergy by geographic location. Multiple logistic regression models were constructed to estimate the association between geographic location and food allergy.
  
  
  RESULTS
  Data were analyzed for 38 465 children. Increasing population density corresponded with increasing prevalence, from 6.2% in rural areas (95% confidence interval [CI] = 5.6-6.8) to 9.8% in urban centers (95% CI = 8.6-11.0). Odds of food allergy were graded, with odds in urban versus rural areas highest (odds ratio [OR] = 1.7, 95% CI = 1.5-2.0), followed by metropolitan versus rural areas (OR = 1.4, 95% CI = 1.2-1.5), and so on. Significance remained after adjusting for race/ethnicity, gender, age, household income, and latitude.
  
  
  CONCLUSIONS
  An association between urban/rural status and food allergy prevalence was observed.
authors.affiliation: Northwestern University Feinberg School of Medicine, Chicago, IL 60640, USA. rugupta@childrensmemorial.org
authors.forename: Ruchi S
authors.initials: RS
authors.lastname: Gupta
authors.forename: Elizabeth E
authors.initials: EE
authors.lastname: Springston
authors.forename: Bridget
authors.initials: B
authors.lastname: Smith
authors.forename: Manoj R
authors.initials: MR
authors.lastname: Warrier
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Pongracic
authors.forename: Jane L
authors.initials: JL
authors.lastname: Holl
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D005512:Food Hypersensitivity / Q000453:epidemiology / Q000209:etiology*; D006306:Health Surveys; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011156:Population Density; D015995:Prevalence; D012111:Residence Characteristics; D012423:Rural Health / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology; D014504:Urban Health / Q000706:statistics & numerical data*