Prevalence and Trends in Active Smoking Among Adults Living with HCV in the U.S. over the Last Decade: A Population-Level Analysis.

Background: Smoking in patients with hepatitis C (HCV) amplifies the risk of cirrhosis and hepatocellular carcinoma. We aimed to estimate the prevalence of active smoking over the last decade at the population level among adults living with HCV in the U.S., estimate temporal trends in active smoking, and identify factors associated with active smoking. Methods: We analyzed repeated cross-sectional NHANES data (2007-2018) of adults ≥20 years old with serologic evidence of HCV and complete smoking data (unweighted [n = 621] and weighted [n = 3,620,603] sample size). Temporal trends were evaluated using linear regression and joinpoint regression. Survey-weighted multivariable logistic regression was used to identify factors associated with active smoking. Results: The cumulative prevalence of active smoking was 56.4% (95% CI, 49.2-63.4). Linear trend testing was not significant (p = 0.93). Joinpoint regression suggested a slope change near 2013-2014, but neither segment-specific annual percent changes nor the slope change reached significance. Factors associated with higher odds of active smoking included female sex (aOR = 2.23; 95% CI, 1.17-4.24), low poverty income ratio (aOR = 3.33; 1.41-7.84), lifetime substance use (aOR = 10.63; 3.08-36.70), and depression (aOR = 2.65; 1.29-5.45). Lower odds were observed with >high-school education (aOR = 0.50; 0.26-0.94), obesity (aOR = 0.32; 0.18-0.58), and ≥2 yearly healthcare visits (aOR = 0.27; 0.10-0.68). Conclusions: Smoking appears to be endemic within the HCV population, and rates have remained alarmingly high and stagnant (i.e., unchanged or have not decreased) over the last decade, which consequently can lead to heightened incident cases of HCV-related cirrhosis and hepatocellular carcinoma in the near future.