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Integration of Hepatitis C Testing and Treatment in OAT Clinics in Canada

Introduction

To meet the World Health Organization’s goal of eliminating hepatitis C by 2030, scaling up testing and linkage to care is essential to help identify individuals requiring treatment. Targeting screening programs to populations disproportionately impacted by hepatitis C is one approach to identifying and treating people with hepatitis C. The population most impacted by hepatitis C in Canada is people who use drugs. This is due to the high risk of transmission from sharing injection drug use equipment and social and structural factors (e.g., stigma, the criminalization of drug use, housing insecurity and poverty) that disproportionately impact this population. Researchers in Ontario explored whether integrating hepatitis C screening and treatment within opioid agonist therapy (OAT) clinics would improve testing and treatment outcomes in this population.

OAT clinics are an optimal setting in which to integrate hepatitis C care for several reasons. Research shows that hepatitis C antibody prevalence is high among OAT users because they are people who have previously used or currently use drugs. In Canada, daily, weekly or monthly clinic visits are required to access OAT, which presents multiple opportunities to engage people who have previously used or currently use drugs in hepatitis C screening and treatment. Integrating hepatitis C within OAT clinics may also prevent drop-offs and improve retention across the cascade of care, as frequent clinic visits may enable service providers to engage clients more consistently. Thus, OAT clinics are uniquely positioned to reach people who use drugs.

Study details

The Viral Hepatitis Care Network (VIRCAN) is a research team that has partnered with community-based health centres in Ontario to build capacity for hepatitis C screening and treatment in community settings through education and resource support. In this study, VIRCAN partnered with 24 OAT clinics operating in large Ontario cities and small towns, to integrate hepatitis C testing and treatment within existing OAT programs. Aside from one clinic that only offered buprenorphine, all clinics offered buprenorphine and methadone.

Clinics implemented their own testing strategies in alignment with their program structure. To conduct hepatitis C antibody testing, service providers used a point of care (POC) or dried blood spot (DBS) test. Confirmatory hepatitis C RNA testing was conducted using either DBS testing or serology. Participants who tested positive for a chronic hepatitis C infection (RNA positive) were offered direct-acting antiviral (DAA) treatment by a nurse practitioner or physician at the clinic. The prescription regimen was determined by the treatment provider. Clinics recorded participants’ progression through the hepatitis C care cascade.

Data collection for the study occurred between January 2016 and December 2020. VIRCAN collected de-identified data on participants’ age and self-identified gender, as well as data on the care cascade. Care cascade data included the participants’ antibody result, whether a RNA test was conducted and the RNA test result. For those with a positive RNA test, additional data included appointment setting and attendance, treatment initiation and completion, whether the person completed testing for sustained virological response at 12 weeks post-treatment (SVR12) and if the person achieved SVR12 (cure).

Results

In total, 1,954 people were included in the study sample. The sample consisted of 1,223 (63%) male-identifying individuals with an average age of 40 years. Within the sample:

  • 45% (870 people) tested positive for hepatitis C antibodies
  • among those who were identified as antibody positive, 94% (817 people) received confirmatory hepatitis C RNA testing and 64% (477) received a positive RNA result
  • among those with a positive RNA result, 80% (325) set an appointment for follow-up care
  • among those who set an appointment, 99% (322) attended their first appointment
  • among those who attended their first appointment, 96% (295) started treatment
  • among those who started treatment, 87% (230) completed it
  • among those who completed treatment, 68% (125) submitted SVR12 samples, with 97% (121) achieving SVR12

Of all the people who tested positive for hepatitis C antibodies, 59% (509) had previously received a positive antibody result (i.e., Known Ab+) but had not started treatment and 41% (361) were newly diagnosed as antibody positive (i.e., New Ab+). In a comparison of these two groups, researchers found the following:

  • Individuals who had previously received a positive antibody result were significantly more likely to complete confirmatory RNA testing than those who were newly diagnosed as antibody positive (97% vs. 90%).
  • Individuals who had previously received a positive antibody result were more likely to set follow-up appointments (84% vs. 72%), initiate treatment (98% vs. 91%) and complete SVR testing (75% vs 52%) than those who were newly diagnosed as antibody positive, although these results were not significant.

Interestingly, among both Known Ab+ and New Ab+ individuals, those aged 41 years or older were significantly more likely to complete treatment than those aged 40 and under. The authors suggest that two of the reasons why older individuals were more likely to complete treatment may be that their drug use was more stable and they had a greater awareness of the risk of developing liver disease from chronic hepatitis C infection.

Only 27 people had blood samples collected by DBS test kits for both antibody and RNA testing. The remaining participants completed POC antibody tests, followed by serology for RNA testing. While 100% of individuals who received DBS testing had an RNA test completed, only 94% of participants who had serology completed RNA testing, but this difference was not significant.

Integration of hepatitis C care within OAT programs

Findings from this study suggest that OAT programs are ideally positioned to reach people who previously injected or currently inject drugs to engage them in hepatitis C testing and treatment. Of the 870 individuals who tested positive for hepatitis C antibodies, 41% were newly identified as antibody positive and 59% were people who already knew they were antibody positive. As such, incorporating routine screening into OAT programs is an effective way to engage and re-engage people in the hepatitis C cascade or care.

Of the individuals who completed SVR12 testing, 97% were cured; these high cure rates align with the results of other interventions with people on OAT and highlight not only the fact that it is possible to reach people who inject drugs through OAT clinics but also the fact that integrating hepatitis C treatment in these settings enables programs to achieve high cure rates. Most importantly, results from this study demonstrate that integrating hepatitis C testing within existing OAT programs is feasible, providing novel pathways that are critical to engage people who use drugs in treatment.

Future considerations

Although integrating hepatitis C screening and treatments within OAT programs may be feasible and effective, retention of individuals at certain points in the cascade of care could be improved. The authors reported that the largest drop-off in the care cascade was at the stage at which SVR12 testing was completed, followed by the stage at which follow-up appointments were scheduled for individuals to receive their RNA test results. Given that OAT recipients generally engage with their doctor or nurse practitioner on a regular basis, the authors suggested scheduling a follow-up appointment at the time of RNA testing, as most people who had a booked appointment attended their appointments. The appointment could simply be cancelled if the RNA test result came back negative.

Additional suggestions to improve retention include setting up automatic reminders for providers in patients’ electronic medical records to schedule follow-up appointments, furthering the integration of social workers and case managers to retain people in care, providing incentives for completion of each step of the care cascade, and considering employing SVR testing in week 4 post-treatment (SVR4) for patients without cirrhosis or with compensated cirrhosis who may otherwise be lost to follow-up. Integration of hepatitis C screening and treatment with additional clinical and harm reduction services that reach people who inject drugs (e.g., safer supply distribution programs, primary care providers, injectable OAT [iOAT] and OAT telemedicine programs) may warrant further exploration as well.

Limitations

The findings from this study must be considered in light of the study’s limitations. VIRCAN partnered with 24 OAT clinics across Ontario but the researchers were unable to follow study participants’ care outside of these partnerships. This meant that if a participant transferred their care to a clinic not affiliated with VIRCAN or if they were incarcerated after they received screening or after treatment was initiated, they were considered lost to follow-up. Even though some participants may have continued to receive care and be cured of hepatitis C, the study’s data collection processes did not allow the researchers to continue to capture this information.

The researchers also did not have access to information about certain factors that may have impacted screening uptake and participant retention across the cascade of care, such as information about participants’ OAT doses and dosing scheduling, the type of OAT participants received, their duration of OAT and the hepatitis C treatment dispensing models that were used. Inclusion of these data may have helped to contextualize the study results.

REFERENCE:

Wolfson-Stofko B, Hirode G, Vanderhoff A, et al. Real-world hepatitis C prevalence and treatment uptake at opioid agonist therapy clinics in Ontario, Canada. J Viral Hepat. 2024;31(5):240-247.

Source: CATIE