Evaluating the Chain of Addiction Care (CAC)

Study Overview
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Brief Summary
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The investigators want to evaluate the feasibility of a decentralised hepatitis C care pathway (the Chain of Addiction Care (CAC) pathway) in several addiction care centres in the east of the Netherlands. Secondary objective: to measure the impact of hepatitis C clearance on MET (+metabolite) and BUP (+metabolite) trough levels in patients on Opioid substitution Therapy (OST). This is an exploratory, observational study.

Detailed Description
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People who (have) inject(ed) drugs (PWID) are at high risk for hepatitis C infection. Establishing adequate linkage to care in this population can be a challenge. Many of these patients receive opioid substitution, hepatitis C treatment possibly influences pharmacokinetics of those substitutes. This protocol describes a study on hepatitis C in people who (have) inject(ed) drugs (PWID), consisting of two substudies. 1) An exploratory, observational study in which we evaluate the decentralised hepatitis C care pathway in addiction care centres. 2) An observational pharmacokinetic study in hepatitis C patients on opioid substitution therapy (OST) embedded within the first study. Rationale: 1) Many PWIDs are lost during the process of testing and linkage to care and do therefore not receive adequate hepatitis C treatment. Decentralising care in addiction care centres deems hospital visits unnecessary, an approach that has become increasingly popular in this population over the last few years. This practice however has not yet been evaluated in the Netherlands. 2) In the Netherlands the PWID population is often treated for opioid addiction by opioid substitution therapy (OST) with methadone (MET) or buprenorphine (BUP). There is evidence that liver inflammation has a negative effect on pharmacokinetics of drugs. Consequently, we hypothesize that HCV treatment results in reduced liver inflammation and a decrease in MET and/or BUP levels, which is clinically relevant in the PWID/OST population. Objective: 1) to evaluate the feasibility of a decentralised hepatitis C care pathway (the Chain of Addiction Care (CAC) pathway) in several addiction care centres in the east of the Netherlands. 2. to measure the impact of hepatitis C clearance on MET (+metabolites) and BUP (+metabolites) levels and craving in patients on OST. Study design: This is an exploratory, observational study with a pharmacokinetic observational study embedded within the same population.

Official Title
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Evaluating the Hepatitis C Chain of Addiction Care Pathway for People Who Inject(ed) Drugs in Addiction Care

Conditions
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Hepatitis C, Chronic, Substance Use Disorders

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 18 years or older Able and willing to give informed consent Currently inject or previously injected drugs at least once, including nasal snorting of drugs using aids such as basepipes or straws. Visit the participating addiction care centre at least once during the study period Exclusion Criteria: none

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Participants<br>Consecutive people who use drugs and visit the addiction care centre | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| HCV prevalence (both anti-HCV and HCV RNA). | Participants are invited to undergo viral hepatitis screening (standard care) | At screening (week 0) | 
| Treatment acceptance rate. | Participants with chronic HCV infection are invited to be treated (standard care) | After evaluation ( week 3) | 
| Sustained virologic response | Participants who were treated and were 'cured' (standard care) | 12 weeks after treatment ( week 30) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acceptance rate of on-site testing. | Number of participants that engage in testing | through study completion, an average of 1 year | 
| Re-infection rate. | Patients re-infected after successful treatment | through study completion, an average of 1 year | 
| Mean decrease in MET and BUP trough levels | Difference in concentration of methadone or buprenorphine before and after treatment. | through study completion, an average of 1 year | 
| Change in dosage of MET and BUP during follow-up | Physician initiated dosage change before compared to after treatment of hepatitis C | through study completion, an average of 1 year | 
| Patient reported drug use | Drug use during study timeframe | through study completion, an average of 1 year |