RATE OF METHADONE USE AMONG ABORIGINAL OPIOID INJECTION DRUG
USERS

Evan Wood, MD PhD, Julio S. Montaner, MD, Kathy Li, MSc, Lucy Barney,
RN MSN, Mark W. Tyndall, MD ScD and Thomas Kerr, PhD

From the British Columbia Centre for Excellence in HIV/AIDS (Wood,
Montaner, Li, Tyndall, Kerr), St. Paul's Hospital; the Department of
Medicine (Wood, Montaner, Kerr), University of British Columbia; and
the British Columbia Centre for Disease Control (Barney), Vancouver,
BC

Correspondence to: Dr. Evan Wood, British Columbia Centre for
Excellence in HIV/AIDS, Rm. 608, 1081 Burrard St., Vancouver BC V6Z
1Y6; fax 604 806-9044; ewood@cfenet.ubc.ca

Background: Previous studies have shown elevated
rates of health-related harms among Aboriginal
people who use injection drugs such as heroin.
Methadone maintenance therapy is one of the most
effective interventions to address the harms of
heroin injection. We assessed the rate of
methadone use in a cohort of opioid injection
drug users in Vancouver and investigated whether
methadone use was associated with Aboriginal ethnic background.

Methods: Using data collected as part of the
Vancouver Injection Drug Users Study (May
1996--November 2005), we evaluated whether
Aboriginal ethnic background was associated with
methadone use using generalized estimating
equations and Cox regression analysis. We
compared methadone use among Aboriginal and
non-Aboriginal injection drug users at the time
of enrolment and during the follow-up period, and
we evaluated the time to first methadone use
among people not using methadone at enrolment.

Results: During the study period, 1603 injection
drug users (435 Aboriginal, 1168 non-Aboriginal)
were recruited. At enrolment, 54 (12.4%)
Aboriginal participants used methadone compared
with 247 (21.2%) non-Aboriginal participants
(odds ratio [OR] 0.53, 95% confidence interval
[CI] 0.38--0.73, p ( 0.001). Among the 1351
(84.3%) participants who used heroin, Aboriginal
people were less likely to use methadone
throughout the follow-up period (adjusted OR
0.60, 95% CI 0.45--0.81, p ( 0.001). Among people
using heroin but who were not taking methadone at
enrolment, Aboriginal ethnic background was
associated with increased time to first methadone
use (adjusted relative hazard 0.60, 95% CI 0.49--0.74, p ( 0.001).

Interpretation: Methadone use was lower among
Aboriginal than among non-Aboriginal injection
drug users. Culturally appropriate interventions
with full participation of the affected community
are required to address this disparity.