Reductions to health-related quality of life associated with cigarette use, e-cigarette use, and depression among US adults.

Introduction: Prior studies suggest e-cigarette use is associated with worse health outcomes, but it remains unclear whether these associations persist independent of cigarette smoking and diagnosed depression and how they jointly affect health-related quality of life (HRQoL). This study provides the first health utility estimates of the independent and combined effects of cigarette use, e-cigarette use, and depression. Methods: We analyzed 2022-2023 Behavioral Risk Factor Surveillance System data, evaluating self-reported physically or mentally unhealthy days. Average unhealthy days were estimated by age, gender, smoking status, depression status, and current e-cigarette use status. Overall healthy days were converted EQ-5D utility scores. Results: Cigarette use, e-cigarette use, and depression were each associated with more mentally and physically unhealthy days, with a more pronounced association observed for mental health. E-cigarette use alone was associated with 2.9-4.2 additional mentally unhealthy days and 1.3-2.8 additional physically unhealthy days per month across adult age groups, with the highest number of additional unhealthy days observed when all three conditions co-occurred. Whether with or without co-diagnosed depression, e-cigarette use was independently associated with poorer mental health among adults aged 18-64. Among young adults, e-cigarette use demonstrated measurable health disutility after accounting for cigarette use and depression. Conclusion: E-cigarette use is independently associated with poorer HRQoL, particularly among younger adults, and these negative associations scale upward when combined with cigarette smoking and depression. Quantifying these joint impacts as health disutility underscores the necessity of integrating e-cigarette cessation into comprehensive tobacco control and mental health policies.