Interaction between asthma and smoking increases the risk of adult airway obstruction

Abstract

The aim of the present study was to analyse the interaction between asthma and smoking in the risk of adult airway obstruction, accounting for atopy. In the European Community Respiratory Health Survey, 15 668 persons aged 20-56 years underwent spirometry in 1991-1993 and 9 years later (n=8916). Risk of airway obstruction and lung function decline associated with smoking and early-onset (10 years of age) asthma were analysed with generalised estimating equation models and random-effect linear models, adjusting for covariates. Interaction of asthma with smoking was expressed as relative excess risk due to interaction (RERI). A 20-fold increase in adult airway obstruction was found among those..