Health care utilization and costs associated with direct-acting antivirals for patients with substance use disorders and chronic hepatitis C

BACKGROUND: Patients with substance use disorders (SUD) and chronic hepatitis C virus infection (HCV) have limited access to direct-acting antivirals (DAAs) due to multilevel issues related to providers (eg, concern about reinfection); patients (eg, refusal); payers (eg, prior authorization); and health system structure, although clinical guidelines recommend timely DAA treatment for patients with SUD and HCV. Effects of DAAs on real-world health care utilization and costs among these patients is unknown. OBJECTIVE: To compare changes in medical service utilization and costs related to liver, SUD, and all-cause morbidity in patients with SUD and HCV treated with DAAs (DAA group) vs not treated with DAAs (non-DAA group). METHODS: We conducted a retrospective cohort study using MarketScan Commercial and Medicare Supplemental Claims databases (2012-2018) for newly diagnosed HCV treatment-naive adults with SUD. We used difference-in-differences analyses, stratified by cirrhosis status, to determine the adjusted ratio of rate ratio (RoRR) to assess the difference in the relative changes from the pre- to posttreatment periods between the 2 groups. RESULTS: 6,266 patients with SUD and HCV were identified. Of these patients who also had cirrhosis (n = 607), 49% (n = 298) initiated DAA therapy for HCV, whereas of those without cirrhosis (n = 5,659), 22% (n = 1,219) initiated DAAs. For patients with cirrhosis (n = 607), the liver-related costs decreased by $6,213 (95% CI = −$8,571, −$3,856) for the DAA group and $1,585 (95% CI = −$4,659, $1,490) for the non-DAA group. The relative decreases in the rate of liver-related costs were larger for the DAA group than for the non-DAA group, and the relative changes between groups were significantly different (RoRR = 0.37, 95% CI = 0.19-0.73). There was no difference in the relative changes after DAAs in the rate of SUD-related visits/costs or all-cause costs between the 2 groups. For patients without cirrhosis (n = 5,659), a similar association was observed. Besides, the relative decreases in the rate of SUD-related emergency department (ED) visits (RoRR = 0.54, 95% CI = 0.38-0.77); SUD-related long-term care visits (RoRR = 0.30, 95% CI = 0.13-0.73); all-cause ED visits (RoRR = 0.75, 95% CI = 0.64-0.88); and all-cause long term-care visits (RoRR = 0.36, 95% CI = 0.18-0.72) were larger in the DAA group than in the non-DAA group. CONCLUSIONS: DAAs are associated with a significant decrease in the rate of SUD-related ED visits and liver-related costs without increasing the rate of all-cause costs among patients with SUD and HCV, suggesting that the benefits of DAAs extended beyond liver-related outcomes, especially in this disadvantaged population.