Discriminant analysis and logistic regression on genetic history and environmental factors in children with asthma

Asthma is known to be related to genetic and environmental factors, we aimed to identify the predictors discriminating between children with asthma and a control group in order to build typical profiles of these children.

A multidimensional analysis covered children (58 with asthma and 217 as control group), under 17 years of age, involving environmental variables and medical history of these children and their families.

Chi-square tests highlighted significant links between variables as rhinitis and conjunctivitis (P<0.001). The results showed, in group of asthmatic children, significant high frequencies of allergies, mainly seasonal (P<0.001), rhinitis, family history more present in mothers (P=0.002) and in maternal aunts and uncles (P<0.02). Allergies were mostly present in mothers of asthmatic children (P=0.03). Children whose father, mother or both had asthma were significantly more numerous in asthmatic group (P=0.0007). A multiple correspondence analysis (MCA) identified two typical profiles of children, a first group of asthmatic children with positive modalities of family history, medical and environmental factors, a second, the control group (nA, non-asthmatic children), with essentially negative modalities of the variables. Logistic regression (LR) resulted in a final model which retained four significant predictors, rhinitis (P=0.01), atopic dermatitis (P=0.04), mother antecedents (P=0.03) and paternal uncle antecedents (P=0.008) with a globally appreciable predictive value (82%) of the Hosmer-Lemeshow Test.

These results allowed the drafting of a typical profile quantifying through a function of a few predictors, the variation of the probability for a child to develop an asthma.