Late Breaking Abstract - Long-term household air pollution profiles and novel cough subclasses in a middle-aged Australian cohort.

<bold>Background:</bold> Evidence on associations between household air pollution and cough is lacking, especially in developed countries. <bold>Methods:</bold> Seven longitudinal household air pollution profiles (HAPs) incorporating heating and cooking methods, smoking, and mould at home from age 43 to 53 years (Dai, X. et al. Eur Respir J 2021; 57:2000602) and six cross-sectional cough subclasses at age 53 years (Zhang, J. et al. Lancet Resp Med 2024; 12(2):129-140) have been identified previously in the Tasmanian Longitudinal Health Study. Associations between HAPs and the cough subclasses were assessed using multinomial logistic regression. Sensitivity analyses were conducted using individual household air pollution exposures and standard cough definitions (chronic cough, chronic phlegm, and chronic bronchitis). <bold>Results:</bold> Of the 2838 participants included in the analysis, significant associations were found between HAPs featuring wood heating and smoking and all cough subclasses (e.g., adjusted OR, aOR=7.36, 95%CI: 2.56-21.17 for “wood heating/smoking” and “chronic productive cough”), standard definitions of chronic cough and chronic bronchitis, compared to the least exposed HAP (electric cooking and air condition). Three HAPs were associated with the “cough with allergies” subclasses, including “All electric (aOR=1.67, 95%CI: 1.00-2.79)”, “wood heating (aOR=2.05, 95%CI: 1.16-3.63)”, and “wood heating/gas cooking (aOR=1.87, 95%CI: 1.01-3.46)”. <bold>Conclusion:</bold> Household exposure to wood heating and smoking over 10 years increased the risks of cough in middle age. Additionally, wood heating, gas cooking, and electric heating increased the risks of allergic cough independent from tobacco smoking.