Objective: To examine trends in the direct acting antiviral (DAA) uptake in a multi-state Medicaid population with hepatitis C virus (HCV) prior to and after ledipasvir/sofosbuvir (LDV/SOF) approval and changes in prior authorization (PA) requirements.

Data sources: Analyses utilized enrollment, medical, and pharmacy claims in four states, December 2013-December 2017.

Study design: An interrupted time series examined trends in uptake (1+ claim for a DAA) before and after two events: LDV/SOV approval (October 2014) and lifting of PA requirements for 40% of members (July 2016). Analyses were also performed in subgroups defined by the number and dates of change in PA requirements in members' Medicaid plans.

Data collection/extraction methods: Members aged 18-64 years with an ICD code for HCV were included in the sample from diagnosis date until treatment initiation or Medicaid disenrollment.

Principal findings: The annual sample size ranged from 38,302 to 45,005 with approximately 30% ages 18-34 years and 40% female. In December 2013, 0.08% was treated, rising to 0.74% in December 2017 (p < 0.001). Uptake increased from 0.34%/month in October 2014 to 0.70%/month after LDV/SOF approval, (p < 0.001), and increased relative to the pre-LDV/SOV trend through June 2016 (p = 0.04). Uptake increased to 1.18%/month after PA change, (p < 0.001) and remained flat through 2017 (p = 0.64). Cumulatively, 20.1% were treated by December 2017. In plans with few/no requirements through 2017, uptake increased to 1.19%/month after LDV/SOF approval (p < 0.001) and remained flat through 2017 (p = 0.11), with 22.2% cumulatively treated. Among plans that lifted PA requirements from three to zero in mid-2016, uptake did not increase after LDV/SOF approval (p = 0.36) but did increase to 1.41%/month (p < 0.001) after PA change, with 18.1% cumulatively treated.

Conclusions: HCV Treatment increased through 2017. LDV/SOF approval and lifting PA requirements led to an increase in uptake followed by flat monthly utilization. Cumulative uptake was higher in plans with few/no PA requirements relative to those with three requirements through mid-2016.