Factors associated with illicit methadone injecting in a Canadian setting.
OBJECTIVE
While methadone is well established as an evidence-based treatment for opioid use disorder, safety concerns persist regarding its diversion. The authors examine the prevalence of and risk factors associated with injection of methadone in an urban population.


METHODS
Between December 2005 and November 2013, data were derived from two open prospective studies of persons who inject drugs (PWID) in Vancouver, Canada. Generalized estimating equations (GEE) logistic regression was used to determine factors independently associated with illicit methadone injecting.


RESULTS
During the study, 1911 individuals (34% women) were recruited; 134 (7%) participants reported methadone injecting at least once. In multivariable analysis, Caucasian ethnicity [adjusted odds ratio (AOR) = 1.90, 95% confidence interval (CI) = 1.20-3.00]; homelessness (AOR = 1.46, 95% CI = 1.09-1.95); drug dealing (AOR = 2.10, 95% CI = 1.50-2.93); ≥daily heroin injection (AOR = 1.57, 95% CI = 1.08-2.26); ≥daily crack smoking (AOR = 2.06, 95% CI = 1.44-2.95); being a victim of violence (AOR = 1.48, 95% CI = 1.04-2.12); and non-fatal overdose (AOR = 1.67, 95% CI = 1.67 (1.00-2.79) were independently and positively associated with methadone injection; female gender (AOR = 0.47, 95% CI = 0.30-0.75) was negatively associated.


CONCLUSIONS
The diversion of methadone for illicit injection in this urban setting was associated with several markers of addiction severity and other health and social vulnerabilities.


CONCLUSIONS
These findings underscore the need to ensure methadone accessibility while limiting diversion-related risk.
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, Vancouver, BC, Canada.
Devin
D
Tucker
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, Vancouver, BC, Canada.|Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
M-J
MJ
Milloy
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, Vancouver, BC, Canada.|Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
Kanna
K
Hayashi
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, Vancouver, BC, Canada.|Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
Paul
P
Nguyen
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, Vancouver, BC, Canada.|Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
Thomas
T
Kerr
British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, Vancouver, BC, Canada.|Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
Evan
E
Wood
D000328:Adult; D002170:Canada / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008691:Methadone / Q000008:administration & dosage*; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012651:Self Medication / Q000706:statistics & numerical data*; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*; D014505:Urban Population / Q000706:statistics & numerical data
D008691:Methadone