Risk of secondhand smoke exposure and severity of COVID-19 infection: multicenter case–control study

Introduction Exposure to secondhand smoke (SHS) is an established causal risk factor for cardiovascular disease (CVD) and chronic lung disease. Numerous studies have evaluated the role of tobacco in COVID-19 infection, severity, mortality but missed opportunity assess SHS. Therefore, this study was conducted determine whether SHS independent mortality, other co-morbidities. Methodology Multicentric case–control across six states India. Severe patients were chosen as our cases, mild moderate control exposure The sample size calculated using Epi-info version 7. A neighborhood-matching technique utilized address ecological variability enhance comparability between cases controls, considering age sex additional matching criteria. binary logistic regression model used measure association, results presented adjusted odds ratio. data analyzed SPSS 24 (SPSS Inc., Chicago, IL, USA). Results total 672 severe 681 controls recruited study. ratio (AOR) at home 3.03 (CI 95%: 2.29–4.02) compared mild/moderate COVID-19, while workplace had 2.19 1.43–3.35). Other factors significantly related severity a history vaccination before illness, body mass index (BMI), attached kitchen home. Discussion suggest that cumulative cigarette illness. More with use biomarkers quantification future are needed.