S2442 Cumulative Prevalence, Temporal Trends, and Determinants of Active Smoking in Adults With Hepatitis C in the Last Decade

Introduction: Smoking in individuals with hepatitis C (HCV) worsens liver injury via oxidative stress, inflammatory pathways, and hepatic stellate cell activation, thereby accelerating fibrosis and raising the risk of cirrhosis and hepatocellular carcinoma. At the population-level, we aimed to examine the prevalence of active smoking, longitudinal trends in the prevalence of active smoking, and identify demographic, clinical, and psychosocial risk factors associated with active smoking among U.S. adults living with HCV. Methods: We conducted a repeated cross-sectional study using nationally representative data from the 2007–2018 National Health and Nutrition Examination Survey (NHANES) (n = 3,620,603 weighted sample size). Adults aged ≥20 years with serologic evidence of HCV and complete smoking data were included. Active smoking (participants indicating ≥100 cigarettes in their lifetime and currently smoking every day or some days) was the primary outcome. We applied survey weights and tested time trends using linear regression of prevalence by survey cycle, and used weighted logistic regression to identify determinants of active smoking. Results: The prevalence of active smoking over the 11-year period was 56.4% (95% confidence interval [CI], 49.2–63.4), corresponding to approximately 2,042,081 million individuals. Trends in active smoking did not decrease but instead remained relatively stable over the 11-year period (trend P = 0.9). In adjusted analyses, female sex (aOR = 2.23, 95% CI 1.17–4.24), low poverty income ratio (aOR = 3.33, 95% CI 1.41–7.84), lifetime substance use (aOR = 10.63, 95% CI 3.08–36.70), and depression (aOR = 2.65, 95% CI 1.29–5.45) were associated with higher odds of active smoking. Conversely, >high school education (aOR = 0.50, 95% CI 0.26–0.94), obesity (aOR = 0.32, 95% CI 0.18–0.58), and ≥2 yearly healthcare visits (aOR = 0.27, 95% CI 0.10–0.68) were associated with lower odds of active smoking. Conclusion: Active smoking among U.S. adults with HCV remains alarmingly high and their trends in active smoking have not decreased over the past decade, whereas trends in the general population have decreased. Socioeconomic disadvantages, psychiatric comorbidity, and substance use were key predictors of active smoking. Regular healthcare engagement appears protective, suggesting that targeted smoking cessation efforts integrated into HCV care—particularly for vulnerable subgroups—could potentially reduce tobacco-related morbidity and improve liver-related outcomes.