1. Engagement in methadone maintenance therapy associated with less time with plasma HIV-1 RNA viral load above 1500 copies/mL among a cohort of HIV-positive people who use drugs in Vancouver, Canada
Presentation prepared for the 22nd International AIDS Conference in Amsterdam, Netherlands
July 25th 2018
Brittany Barker, MPP PhD Candidate, UBC Research Associate, BC Centre on Substance Use

2. I have no conflicts of interest to declare Acknowledgement of xʷməθkwəy̓əm (Musqueam), Skwxwú7mesh (Squamish), and Səl̓ílwətaʔ/Selilwitulh (Tsleil-Waututh) Nations land where my work takes place.

3. Outline Background Study rationale The ACCESS study Methods
Study sample
Results
Discussion

4. Background Elevated plasma HIV-1 RNA viral load (VL):
HIV disease progression
Risk of onward viral transmission
Heightened HIV transmission risk threshold: VL >1500 copies/ml
People who inject drugs (PWID)
>25% of new HIV infections in North America
>80% in some Eastern European and Central Asian countries where HIV outbreaks are occurring

5. Study Rationale People who inject drugs (PWID)
Individual, social and structural barriers to HIV care
Methadone maintenance therapy (MMT)
Reduces incidence of HIV among PWID
Promotes ART initiation and adherence
Does MMT curb onward viral transmission?

6. Objective
Examine relationship between engagement in low-threshold MMT and amount of person time with VL>1500 copies/ml among a cohort of people who use drugs and living with HIV in Vancouver, Canada

7. AIDS Care Cohort to Evaluate Access to Survival Services (ACCESS)
Study design: Community-recruited cohort of people living with HIV/AIDS who use illicit drugs (ongoing since 2005)
Data collection: Interviewer administered questionnaire and blood sample for serologic analysis at baseline and semi-annually
Data linkages: Complete HIV clinical profile (e.g., VL, CD4 cell count, ART dispensation) from central provincial treatment provider (BCCfE Drug Treatment Program)
Setting: Universal no-cost HIV/AIDS care including medications

8. Methods
Sample restricted to all ART-exposed participants with two VL observations
Outcome variable: proportion of time VL>1500 copies/ml (clinical data)
Based on pairs of VL measurements every six months and estimated proportion of time between to recreate VL history1
Explanatory variable: engagement in MMT (self-report)
Generalized estimating questions (GEE)
1Method originally described by Marks et al. AIDS 2015

9. Study sample 5 Dec 2005 – 29 Nov 2017 n=867 PWUD living with HIV
Proportion with VL>1500c/ml
5 Dec 2005 – 29 Nov 2017
n=867 PWUD living with HIV
9062 observations (4532 person-years)
522 (60.2%) engaged in MMT over study period

10. Results

11. Discussion On average, 19% of observation time VL >1500c/ml
Key role of access to evidence-based addiction care
Halting disease progression among PWID
Optimizing ART treatment for comorbid opioid dependence
Lower risk of onward viral transmission in community
Barriers to treatment still persist globally (e.g., US, Russia)
Urgent scale-up of access and integrated evidence-based addiction and HIV treatment and care

12. Acknowledgements
Co-authors: Kit Fairgrieve, Keith Ahamad, Thomas Kerr, Jean Shoveller, Julio Montaner, Evan Wood, and M-J Milloy
ACCESS study participants
Co-investigators and the research team at the BC-CSU
BC-CSU Staff, and Administrative Support: Elaine Fernandes, Peter Vann, Tricia Collingham, Jenny Mathews, Steve Kain, Ana Prado, and the entire study team
Funders: US National Institutes of Health (R01- DA021525), Michael Smith Foundation for Health Research (M-JSM), Canadian Research Chairs Program (EW), Canadian Institutes of Health Research (BB & M-JSM), NIDA/NIH (JM)