Atopic family history. Validation of instruments in a multicenter cohort study

In order to identify newborns at risk for atopic diseases, we developed a family questionnaire and selected specific answers which were suitable to identify atopic family members. The validity of the questionnaire was evaluated by the Phadiatop test results of 793 mothers and 353 fathers. As both screening instruments do not measure the same, the Phadiatop test identifies sensitization to inhalant allergens and the history reflects the clinical manifestation of atopic disease, the agreement between sensitization and manifestation is incomplete. Sensitivity and specificity of the questionnaire screening conditions to reproduce the Phadiotop test result was 64% and 84% for mothers, and 58% and 88% for fathers, respectively. The relative risk for lifetime prevalence of atopic manifestations in Phadiatop positive over negative mothers was calculated to be 3.88 (95% confidence interval = 3.12 to 4.81), and for Phadiatop positive over negative fathers to amount 4.84 (95% confidence interval 3.25 to 7.23). A few relevant answers of 20 were identified by logistic regression analysis to predict the Phadiatop test result nearly, as well as the total questionnaire.