The mediating role of negative emotions in the relationship between smoking and health-related quality of life among Chinese individuals: A cross-sectional study.

Introduction: Although the negative impact of smoking on health has been confirmed in various studies, few have explored psychological factors mediating the relationship between smoking and health-related quality of life (HRQOL). This study aimed to investigate the relationship between smoking and HRQOL in the Chinese population and the mediating role of negative emotions (NEs).

Methods: Survey data were derived from a cross-sectional study conducted in China from 20 June to 31 August 2022. We recruited participants from 148 cities across the country using a stratified multistage sampling method. The HRQOL of the dependent variable was measured using the Chinese version of European Quality of Life-5 Dimensions (EQ-5D-5L). The Patient Health Questionnaire (PHQ-9), Generalized Anxiety Disorder (GAD-7), and Perceived Stress Scale (PSS-4) were used to measure NE parameters including depression, anxiety, and perceived stress, as the intermediate variables. A multiple parallel mediation model was used to analyze the mediating role of NEs in smoking and HRQOL.

Results: A total of 21916 valid questionnaires were collected, of which 3010 (13.7%) and 18906 (86.3%) were categorized into smokers and non-smokers, respectively. The HRQOL (EQ-VAS score) of smokers (71.70 ± 23.08) was lower than that of non-smokers (73.69 ± 21.32), whereas the depression and anxiety levels of smokers were higher than those of non-smokers (all p<0.001). Moreover, smoking, NEs (depression and anxiety), and HRQOL showed pairwise correlations. According to the mediation analysis, depression (β= -0.461; 95% BCa CI: -0.664 - -0.268) and anxiety (β= -0.279; 95% BCa CI: -0.435 - -0.138) mediated the relationship between smoking and HRQOL after adjusting for demographic and life factors.

Conclusions: These findings emphasize the necessity of studying the interaction between smoking, HRQOL, and Nes, and complementing the research on the impact of psychological factors on the HRQOL of smokers. Public health activities should focus on mental health and take targeted measures for the prevention, treatment, and rehabilitation of smokers.