Scott B Patten1, Jeanne V A Williams2, Dina H Lavorato2, Benjamin Woolf3, Jian Li Wang4, Andrew G M Bulloch4, Tolulope Sajobi5. 1. Department of Community Health Sciences, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, Canada T2N 4Z6; Department of Psychiatry, University of Calgary, Canada; Mathison Centre for Mental Health Research & Education, Hotchkiss Brain Institute, Canada. Electronic address: patten@ucalgary.ca. 2. Department of Community Health Sciences, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, Canada T2N 4Z6. 3. Oxford University, Oxford, UK. 4. Department of Community Health Sciences, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, Canada T2N 4Z6; Department of Psychiatry, University of Calgary, Canada; Mathison Centre for Mental Health Research & Education, Hotchkiss Brain Institute, Canada. 5. Department of Community Health Sciences, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, Canada T2N 4Z6; Department of Clinical Neurosciences, University of Calgary, Canada; O'Brien Institute for Public Health, Canada.
Abstract
BACKGROUND: Epidemiological studies have consistently linked smoking to poor mental health. Among non-smokers, some studies have also reported associations between secondhand smoke exposure and psychological symptoms. However, an association between secondhand smoke exposure and depressive disorders has not been well established. METHODS: This analysis used cross-sectional data from a series of 10 population surveys conducted in Canada between 2003 and 2013. The surveys targeted the Canadian household population, included a brief structured interview for past year major depressive episode (MDE) and included items assessing secondhand smoke exposure. We used two-stage individual-level random-effects meta-regression to synthesize results from these surveys. RESULTS: Over the study interval, about 20% of non-smokers reported substantial exposure to secondhand smoke. In this group, the pooled annual prevalence of MDE was 6.1% (95% CI 5.3-6.9) compared to 4.0% (95% CI 3.7-4.3) in non-smokers without secondhand smoke exposure. The crude odds ratio was 1.5 (95% CI 1.4-1.7). With adjustment for a set of potential confounding variables the odds ratio was unchanged, 1.4 (95% CI 1.2 - 1.6). CONCLUSIONS: These results provide additional support for public health measures aimed at reducing secondhand smoke exposure. A causal connection between secondhand smoke exposure and MDEs cannot be confirmed due to the cross-sectional nature of the data. Longitudinal studies are needed to establish temporal sequencing.
BACKGROUND: Epidemiological studies have consistently linked smoking to poor mental health. Among non-smokers, some studies have also reported associations between secondhand smoke exposure and psychological symptoms. However, an association between secondhand smoke exposure and depressive disorders has not been well established. METHODS: This analysis used cross-sectional data from a series of 10 population surveys conducted in Canada between 2003 and 2013. The surveys targeted the Canadian household population, included a brief structured interview for past year major depressive episode (MDE) and included items assessing secondhand smoke exposure. We used two-stage individual-level random-effects meta-regression to synthesize results from these surveys. RESULTS: Over the study interval, about 20% of non-smokers reported substantial exposure to secondhand smoke. In this group, the pooled annual prevalence of MDE was 6.1% (95% CI 5.3-6.9) compared to 4.0% (95% CI 3.7-4.3) in non-smokers without secondhand smoke exposure. The crude odds ratio was 1.5 (95% CI 1.4-1.7). With adjustment for a set of potential confounding variables the odds ratio was unchanged, 1.4 (95% CI 1.2 - 1.6). CONCLUSIONS: These results provide additional support for public health measures aimed at reducing secondhand smoke exposure. A causal connection between secondhand smoke exposure and MDEs cannot be confirmed due to the cross-sectional nature of the data. Longitudinal studies are needed to establish temporal sequencing.
Authors: Xiaohua Ye; Jingya Huang; Liang Xia; Xiaojun Xu; Xiao Gong; Yanjun Xu Journal: Int J Environ Res Public Health Date: 2019-04-08 Impact factor: 3.390