Sustained Virologic Response and Costs Associated with Direct-Acting Antivirals for Chronic Hepatitis C Infection in Oklahoma Medicaid

BACKGROUND: Outcomes involving newer direct-acting antiviral (DAA) hepatitis C virus (HCV) regimens have not been studied extensively among the Medicaid population. OBJECTIVE: To assess clinical (treatment failure) and economic outcomes for chronic HCV-infected Oklahoma Medicaid members following treatment with DAAs and to measure associations with patient, treatment, and clinical characteristics. METHODS: This cross-sectional study used Oklahoma Medicaid pharmacy and medical claims data for adult members who used a newer DAA agent and had reported a successful or failed sustained virological response rate 12 weeks after therapy completion (SVR12) from January 1, 2014, to June 30, 2016. Multivariable logistic and gamma regressions assessed predictors of SVR12 failure and costs controlling for member demographics (i.e., age, sex, race, rural residence); type of DAA and adherence; clinical characteristics (e.g., comorbid conditions, advanced liver disease); and the implementation of changes to a prior authorization program. RESULTS: Of 934 Medicaid members eligible for treatment with DAAs between January 1, 2014, and June 30, 2016, 906 received DAA treatment, 40.6% (368/906) had reported SVR12 outcomes, and 59.4% (n = 538) did not have a reported SVR recorded. Of those with reported SVR12 outcomes, patients were 53.1 ± 9.7 years of age, 51.1% were male, 8.4% had SVR12 failure, and each member had mean costs of $140,283 ± $52,779. Multivariable analyses indicated higher odds of SVR12 failure was independently associated with cirrhosis (OR [decompensated] = 6.69 and OR [compensated] = 3.52, P < 0.001), while males had higher odds of failure than females (OR = 3.34, P < 0.010). No significant difference in SVR12 failure was noted, according to DAA type or a medication adherence threshold of > 95%. Ledipasvir/sofosbuvir was independently associated with lower costs (exp[b] = 0.81; P < 0.001) compared with sofosbuvir, while higher costs were associated with decompensated cirrhosis (exp[b] = 1.22; P < 0.001) and treatment failure (exp[b] = 1.18, P < 0.010). In an analysis including members without reported SVR12 outcomes, decompensated and compensated cirrhosis had lower odds (P < 0.001) of no reported SVR12 from ambulatory clinic settings. CONCLUSIONS: Almost 60% of Medicaid members receiving DAA treatment did not have a final reported SVR12 outcome. Among those with viral load measurements, treatment success was high and both decompensated and compensated cirrhosis were independently associated with significantly higher odds of treatment failure. Addressing a loss to follow-up among HCV patients and curtailing the development of cirrhosis to improve treatment success may warrant interventions that improve access to care and remove barriers that impede treatment initiation and completion.