Effect of exposure to second-hand smoke on the quality of life: A nationwide population-based study from South Korea

Background. Although exposure to second-hand smoke (SHS) has been associated with various medical conditions, only limited data are available on its association with health-related quality of life (HRQOL), particularly data obtained with the EQ-5D or EQ visual analogue scale (VAS). Methods. This cross-sectional study evaluated 10,532 adult never-smokers who participated in the fifth Korea National Health and Nutrition Examination Survey. By using linear regression models to adjust for possible confounders and incorporating survey weights in analyses, the association between exposure to SHS and HRQOL-measured with the EQ-5D index and the EQ-VAS score-was evaluated. Data were further stratified by the amount of exposure time. Results. After weighted analysis and adjustment, exposure to SHS was significantly associated with lower measures on the EQ-5D index (β = -0.007, P = 0.005) and EQ-VAS score (β = -1.936, P < 0.001). When comparing the unexposed group with the groups exposed <2h/day and ≥2h/day, exposure to a longer duration of SHS was significantly associated with lower scores on the EQ-5D index and the EQ-VAS score. Conclusion. In conclusion, exposure to SHS was associated with reduced HRQOL measured by the EQ-5D index and EQ-VAS score, revealing a dose-response relationship.