Inequities in HCV Care Cascade Engagement Persist, Even After Introduction of DAA Therapy

Ana Maria Passos-Castilho

Credit: Canadian Network on Hepatitis C

Findings from a recent study are providing an overview of engagement with the hepatitis C virus (HCV) care cascade before and after the introduction of direct-acting antivirals (DAAs) in Quebec, Canada, highlighting continued inequities for testing and treatment among vulnerable subgroups.¹

Although results showed overall engagement in the HCV care cascade improved in the post-DAA era, they also called attention to certain populations to strategically target for RNA testing and treatment initiation in order to achieve HCV elimination, including people who inject drugs (PWID), patients in the 1945–1965 birth cohorts, those living with material and social deprivation, and individuals with alcohol use disorder.¹

“The elimination of hepatitis C virus infection as a public health threat is possible given the availability of curative, well-tolerated, oral direct-acting antivirals,” Ana Maria Passos-Castilho, postdoctoral researcher in epidemiology and public health at McGill University, and colleagues wrote.¹ “To achieve this goal, a high uptake in all steps of the HCV care cascade for all groups at risk will be necessary.”

In 2016, the World Health Organization (WHO) set a goal to eliminate viral hepatitis as a public health problem by 2030, including a 90% reduction in incidence and a 65% reduction in mortality compared with a 2015 baseline. Although DAAs offer an effective cure for HCV, access to treatment and care remain an issue for many vulnerable patient populations. Understanding which populations are not progressing through the care cascade can help identify opportunities for targeted intervention to help meet the WHO elimination goal.²

To assess predictors of progression through the care cascade and identify changes between the pre- and post-DAA era, investigators conducted a population-based, retrospective cohort study of all reported hepatitis C diagnoses in Quebec, Canada, between January 1, 1990, and December 31, 2018, in the reportable disease database or the Quebec Public Health Laboratory database. Investigators defined the pre-DAA period as 1990–2013 and the post-DAA period as 2014–2018, acknowledging most (64%) of the treatment initiations in 2014 were DAA medications.¹

The steps along the care cascade included individuals who met the following criteria at any time from HCV diagnosis to December 31 of the year of the cascade:

1. A confirmed positive HCV antibody or a positive HCV RNA
2. RNA-tested, defined as the presence of the first HCV RNA test in the database after diagnosis
3. RNA-positive based on HCV RNA test
4. HCV genotype tested
5. Initiated HCV-specific antiviral treatment
6. Achieved a sustained viral response (SVR), defined as a negative RNA test at least 10 weeks after last antiviral was dispensed

Investigators calculated the proportion of people at a given step relative to the number of people in the previous step, except for the proportion of those with an SVR, for which the denominator was the number of individuals assessed for SVR after treatment initiation.¹

Of the 31,439 HCV-diagnosed individuals who were alive by the end of 2018, the mean age was 41.5 (Standard deviation [SD], 12.9) years and 66% were male. Investigators additionally noted 55% of these individuals were born during 1945–1965, 45% were PWID, and 15% were immigrants born outside of Canada.¹

Results showed substantial improvement in the care cascade from 2013 to 2018. Of note, 86% vs 77% of the individuals with an HCV diagnosis received RNA testing, and 70% vs 45% of the RNA-positive individuals initiated treatment in the pre- and post-DAA eras, respectively.¹

The median time to RNA testing after HCV diagnosis as of 2018 was 1.8 (Interquartile range [IQR], 0.3–6.2) years overall and 0.2 (IQR, 0.1–0.5) years among the individuals diagnosed in the post-DAA period. The probability of receiving RNA testing among all the HCV-diagnosed individuals was greater and occurred in a shorter period in 2018 compared to 2013.¹

The median time to treatment initiation after an initial positive RNA test up to 2018 was 2.4 (IQR 0.7–6.6) years overall and 0.6 (IQR 0.2–1.3) years among the individuals diagnosed in the post-DAA period. In 2013, it took 22 years to achieve a 50% probability of treatment initiation after a positive RNA test, whereas in 2018, this occurred within 7 years.¹

As of 2018, a greater risk of not being RNA-tested or treated was observed among individuals born before 1945 (Hazard ratio [HR], 1.35; 95% CI, 1.16–1.57), those with material and social deprivation (HR, 1.21; 95% CI, 1.06–1.38), and those with alcohol use disorder (HR, 1.21; 95% CI, 1.08–1.360). Overall, non-immigrants had lower rates of RNA testing (HR, 0.76; 95% CI, 0.67–0.85) and treatment initiation (HR, 0.63; 95% CI, 0.57–0.70) than immigrants. PWID had a lower risk of not being RNA tested (HR, 0.67; 95% CI, 0.61–0.85) compared with 2013 (HR, 0.83; 95% CI, 0.76–0.90).¹

Investigators also noted the 1945–1965 birth cohort, compared to the youngest (HR, 0.86; 95% CI, 0.82–0.91) and immigrants (HR, 0.63; 95% CI, 0.57–0.70), had a lower risk of not receiving treatment. However, the risk among immigrants varied significantly – those from Latin America and the Caribbean were approximately 50% more likely to not have initiated treatment as of 2018 compared to those from high income countries in Europe, the United States, Australia, and New Zealand. As of 2018, predictors of not having initiated treatment were older age (born before 1945), alcohol use disorder, material deprivation, and diabetes.¹

“These data provide valuable insights about gaps in care and engagement, with which we can assess important HCV care cascade data that can inform micro-elimination strategies and health service needs in Canada and other low-HCV-prevalence settings,” investigators concluded.¹

References:

1. ^{Passos-Castilho AM, Murphy DG, Blouin K, et al. Ongoing Gaps in the Hepatitis C Care Cascade during the Direct-Acting Antiviral Era in a Large Retrospective Cohort in Canada: A Population-Based Study. Viruses. https://doi.org/10.3390/v16030389}
2. ^{World Health Organization. WHO releases first-ever global guidance for country validation of viral hepatitis B and C elimination. June 25, 2021. Accessed April 12, 2024. https://www.who.int/news/item/25-06-2021-who-releases-first-ever-global-guidance-for-country-validation-of-viral-hepatitis-b-and-c-elimination}