Questionnaire Predictors of Atopy in a US Population Sample: Findings From the National Health and Nutrition Examination Survey, 2005–2006

摘要

Allergic conditions and biochemical measures are both used to characterize atopy. To assess questionnaires’nability to predict biochemical measures of atopy, the authors used data on 5 allergic conditions (allergy, hay fever,neczema, rhinitis, and itchy rash) and serum-specific immunoglobulin E (IgE) levels from the 2005–2006 NationalnHealth and Nutrition Examination Survey. Atopy was defined as 1 or more positive specific IgEs (u00010.35 kU/L).nQuestionnaire responses were assessed for sensitivity, specificity, and positive and negative predictive values fornatopy. In this population-based US sample, 44% of participants were specific IgE-positive and 53% reported atnleast 1 allergic condition. Discordance between atopy and allergic conditions was considerable; 37% of personsnwith atopy reported no allergic condition, and 48% of persons who reported an allergic condition were not atopic.nThus, no combination of self-reported allergic conditions achieved both high sensitivity and high specificity for IgE.nThe positive predictive value of reported allergic conditions for atopy ranged from 50% for eczema to 72% for haynfever, while the negative predictive value ranged from 57% for eczema to 65% for any condition. Given the highnproportion of asymptomatic participants who were specific IgE-positive and persons who reported allergic condi-ntions but were specific IgE-negative, it is unlikely that questionnaires will ever capture the same participants asnthose found to be atopic by biochemical measures.