Use of Direct-Acting Antiviral Agents and Survival among Medicare Beneficiaries with Dementia and Chronic Hepatitis C

Background: Many patients with Alzheimer's disease and related dementia (ADRD) have chronic hepatitis C due to the high prevalence of both conditions among elderly populations. Direct-acting antivirals (DAAs) are effective in treating hepatitis C virus (HCV). However, the complexity of ADRD care may affect DAA use and outcomes among patients with HCV and ADRD. Little information exists on uptake of DAAs, factors associated with DAA use, and health benefits of DAAs among patients with HCV and ADRD. Objective: To examine use and survival benefits of DAAs in Medicare patients with HCV and ADRD. Methods: The study included Medicare patients with HCV between 2014 and 2017. We estimated Cox proportional hazards regressions to examine the association between having ADRD and DAA use, and the relation between DAA use and survival among patients with HCV and ADRD. Results: The adjusted hazard of initiating a DAA was 50% lower in patients with ADRD than those without ADRD (adjusted HR = 0.50, 95% CI: 0.46-0.54). The hazard of DAA use among ADRD patients with behavioral disturbances was 68% lower than non-ADRD patients (adjusted HR = 0.32, 95% CI: 0.28-0.37). DAA treatment was associated with a significant reduction in mortality among ADRD patients (adjusted HR = 0.52, 95% CI: 0.44-0.61). Conclusion: The rate of DAA treatment in patients with HCV and ADRD was low, particularly among those with behavioral disturbance. The survival benefits of DAA treatment for patients with ADRD were substantial.