High-intensity cannabis use and HIV clinical outcomes among HIV-positive people who use illicit drugs in Vancouver, Canada.
Reforms to the legal status of medical and non-medical cannabis are underway in many jurisdictions, including Canada, as are renewed efforts to scale-up HIV treatment-as-prevention (TasP) initiatives. It has been suggested that high-intensity cannabis use may be associated with sub-optimal HIV treatment outcomes. Thus, using data from a setting with a community-wide treatment-as-prevention (TasP) initiative coinciding with increasing access to medical cannabis, we sought to investigate the possible impact of high-intensity cannabis use on HIV clinical outcomes.



Data was derived from the ACCESS study, a prospective cohort of HIV-positive people who use illicit drugs (PWUD) in Vancouver, Canada. Cohort data was confidentially linked to comprehensive clinical profiles, including records of all antiretroviral therapy (ART) dispensations and longitudinal plasma HIV-1 RNA viral load (VL) monitoring. We used generalized estimating equations (GEEs) to estimate the longitudinal bivariable and multivariable relationships between at least daily cannabis use and two key clinical outcomes: overall engagement in ART care, and achieving a non-detectable VL among ART-exposed participants.



Between December 2005 and June 2015, 874 HIV-positive PWUD (304 [35%] non-male) were included in this study. In total, 788 (90%) were engaged in HIV care at least once over the study period, of whom 670 (85%) achieved non-detectable VL at least once. In multivariable analyses, ≥ daily cannabis use did not predict lower odds of ART care (Adjusted Odds Ratio [AOR]: 1.02, 95% confidence interval [CI]: 0.77-1.36) or VL non-detectability among ART-exposed (AOR: 0.96, 95% CI: 0.75-1.21). Upon testing for potential interactions, ≥ daily cannabis use was found to be negatively associated with ART engagement during periods of binge alcohol use (p<0.05).



With the exception of frequent cannabis use during periods of binge alcohol use, our results showed no statistically significant impact of daily cannabis use on the likelihood of ART care or VL non-detectability among ART-exposed HIV-positive PWUD. These findings are reassuring in light of the impending legalization of cannabis in Canada and ongoing efforts to expand TasP initiatives.
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC V6T 1Z3, Canada.
Stephanie
S
Lake
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
Thomas
T
Kerr
Interdisciplinary Studies Graduate Program, University of British Columbia, 270-2357 Main Mall, Vancouver, BC V6T 1Z4, Canada.
Rielle
R
Capler
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC V6T 1Z3, Canada.
Jeannie
J
Shoveller
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada.
Julio
J
Montaner
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada. Electronic address: uhri-mjsm@cfenet.ubc.ca.
M-J
MJ
Milloy
D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000453:epidemiology*; D008875:Middle Aged; D011446:Prospective Studies; D019966:Substance-Related Disorders / Q000150:complications*; D019562:Viral Load
D044966:Anti-Retroviral Agents
Antiretroviral therapy; Cannabis; Cannabis legalization; Human immunodeficiency virus; People who use illicit drugs; Treatment as prevention