Drug use patterns associated with risk of non-adherence to antiretroviral therapy among HIV-positive illicit drug users in a Canadian setting: a longitudinal analysis.
BACKGROUND
Among people living with HIV/AIDS, illicit drug use is a risk for sub-optimal treatment outcomes. However, few studies have examined the relative contributions of different patterns of drug use on adherence to antiretroviral therapy (ART). We sought to estimate the effect of different types of illicit drug use on adherence in a setting of universal free HIV/AIDS treatment and care.


METHODS
Using data from ongoing prospective cohorts of HIV-positive illicit drug users linked to comprehensive pharmacy dispensation records in Vancouver, Canada, we examined factors associated with ≥95% prescription refill adherence using generalized estimating equations (GEE) logistic regression.


RESULTS
Between 1996 and 2013, 692 ART-exposed individuals were followed for a median of 42.7 months (Interquartile Range: 29.1-71.7). In multivariable GEE analyses, heroin injection (Adjusted Odds Ratio [AOR] = 0.75, 95% Confidence Interval [CI]: 0.66-0.85) as well as cocaine injection (AOR = 0.80, 95% CI: 0.72-0.90) were associated with lower likelihoods of optimal adherence. Methadone maintenance therapy (AOR = 1.88, 95% CI: 1.68-2.11) was associated with a greater likelihood of adherence.


CONCLUSIONS
Periods of heroin and cocaine injection appeared to have the most deleterious impact upon antiretroviral adherence. The findings point to the need for improved access to treatment for heroin use disorder, particularly methadone, and highlight the need to identify strategies to support ART adherence among cocaine injectors.
BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, Canada. pouya1844@gmail.com.
Pouya
P
Azar
BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, Canada. uhri-ew@cfenet.ubc.ca.|Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, BC, Canada. uhri-ew@cfenet.ubc.ca.
Evan
E
Wood
BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, Canada. pnguyen@cfenet.ubc.ca.
Paul
P
Nguyen
BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, Canada. maxito35@yahoo.fr.
Maxo
M
Luma
BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, Canada. jmontaner@cfenet.ubc.ca.|Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, BC, Canada. jmontaner@cfenet.ubc.ca.
Julio
J
Montaner
BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, Canada. uhri-tk@cfenet.ubc.ca.|Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, BC, Canada. uhri-tk@cfenet.ubc.ca.
Thomas
T
Kerr
BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, Canada. uhri-mjsm@cfenet.ubc.ca.|Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, BC, Canada. uhri-mjsm@cfenet.ubc.ca.
M-J
MJ
Milloy
D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D002170:Canada; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011446:Prospective Studies; D015819:Substance Abuse, Intravenous / Q000150:complications*; D016896:Treatment Outcome
D013287:Illicit Drugs