title: Direct Acting Antiviral Uptake for Hepatitis C Virus among Medicaid Members with Substance Use Disorder
Creators: name: Clements, Karen M.
name: Kunte, Parag
name: Person, Sharina
name: Greenwood, Bonnie C.
name: Gurewich, Deborah
name: Sefton, Laura
name: Pratt, Carter
name: Clark, Melissa
Publisher: name: eScholarship@UMassChan
Year: 2022

description:  Research Objective: Substance use disorder (SUD) is a risk factor for contracting hepatitis C virus (HCV). Direct acting antivirals (DAA), introduced in late 2013, are highly effective in treating HCV regardless of SUD status. Many state Medicaid agencies initially imposed prior authorization (PA) requirements mandating a period of abstinence or SUD treatment prior to authorizing DAAs in this population. Over time some states relaxed requirements, although as of 2021 such requirements remain in 28 states. We evaluated DAA uptake from 2014‐2017 among Medicaid members to compare uptake among members with and without SUD and to assess the effect of SUD‐related PA requirements over time for predicting treatment among members with SUD. Study Design: This retrospective cohort study used enrollment, medical, and pharmacy claims from Medicaid enrollees in 13 Medicaid plans from three New England states. We used chi‐square tests to compare DAA uptake (1+ pharmacy claims for a DAA) among members with and without an ICD‐9/10 code for SUD and to compare uptake among members with SUD in plans with no SUD‐related PA requirements, plans that lifted requirements between 2014‐2017, and plans with requirements through 2017. Generalized estimating equations with binomial distribution and log link function identified the independent role of SUD‐related PA requirements and calendar time, adjusting for demographic and clinical variables, for predicting uptake. Adjusted risk ratios (aRR) are presented. Population Studied: The population included Medicaid members ages 18‐64 years with HCV (2+ claims with ICD‐9/10 code for HCV or 1+ claim for chronic HCV) from 12/2013–12/2017. Individuals remained in the sample until treatment initiation or Medicaid disenrollment. Uptake was identified through 12/2017. Principal Findings: Overall, 21,186 members (65% of those with HCV) had a SUD diagnosis during the study period. Cumulatively, 13.4% with SUD vs 34.1% without SUD (p<0.0001) were treated for HCV. Among members with SUD, 2,561 (15.2%) members in a plan with no SUD‐related PA requirements, compared with 1,772 (11.5%) in a plan that lifted SUD‐related PA requirements during the study period and 268 (12.8%) in a plan with SUD‐related PA requirements through 2017 (p<0.0001) were treated. In multivariable analyses, members with SUD were less than half as likely to be treated in a month during which SUD‐related PA requirements were in place in their plan relative to months with no SUD‐related PA requirement (aRR = 0.42, 95% CI 0.38‐0.47). Nevertheless, over time uptake increased more steeply, 8%/month, for members during months under SUD requirements (aRR=1.08, 95% CI 1.07‐1.09), and increased 1%/month during months not under requirements (aRR = 1.01, 95%CI 1.01‐1.01). Conclusions: Medicaid members with SUD were less likely to be treated for HCV than their peers without SUD. SUD‐related PA requirements exacerbated the discrepancy in treatment, although over time DAA uptake has increased among members in plans that imposed SUD‐related requirements. Policy implications: While SUD‐related PA requirements limited DAA treatment among Medicaid members with HCV, the increase in treatment over time among members subject to these requirements suggests a clinical, cultural and/or policy shift towards facilitating HCV treatment in this population. Future research ought to explore the merits of continued SUD‐related PA requirements.