A new way of analyzing how the association between lung cancer and indoor air pollution is altered by tobacco use

Abstract

TPS 901: Indoor air pollution, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background: Xuanwei is a city with significantly high lung cancer mortality. Indoor air pollution was a historical risk factor, while tobacco should not be neglected as well there. We aimed to investigate current impacts of indoor air pollution, smoking and SHS exposure on lung cancer risk in Xuanwei, by a conventional process and a novel one, respectively, so that we could also study the methodology for the evaluation of two competitive risk factors. Methods: We followed a case control study design. In conventional analysis process, we built unconditional logistic regression models with both indoor air pollution and smoking or SHS exposure, and estimated their odd ratios (OR) and 95% confidence intervals (CI) at the same time. In novel analysis process, we firstly estimated the OR (95%CI) of indoor air pollution or smoking or SHS exposure separately, and then calculated the alteration smoking or SHS exposure caused on the effect size of indoor air pollution. Results: The ORs estimated for medium or high indoor air pollution level ranged from 2.24 to 4.69 or 6.04 to 9.54, respectively. These values kept the same no matter whether smoking or SHS exposure were included in the models at the same time. Only by using the novel process, we could find out that the effect size of indoor air pollution would decrease 12%-19%, when facing the competition from tobacco. Conclusions: Nowadays, there is still a strong association between lung cancer risk and air pollution in Xuanwei, at the same time the effect of smoking or SHS is gradually highlighted. The issue of indoor air pollution needs to be further solved, while smoking cessation promotion and SHS exposure prevention is also in need. The novel way of analysis should be worth spreading, when there are two kinds of risk factors may be confused with each other.