Printer Friendly

Characteristics and response to treatment among Aboriginal people receiving heroin-assisted treatment.

Opioid dependence, particularly with regard to heroin, is a chronic relapsing disease associated with elevated risks of morbidity and mortality when untreated. (1-3) Based on the current evidence, substitution treatment with opioid agonists mainly methadone--is the most effective approach for attracting and retaining patients in treatment, but a subset of patients do not benefit. In Europe (4-7) and Canada, (8) medically prescribed diacetylmorphine, the active ingredient of heroin, has been shown to be an effective alternative for this subgroup of the most severely affected long-term opioid users.

There is a paucity of evidence in Canada examining the effectiveness of substitution treatment for Aboriginal people who are opioid-dependent. This is particularly concerning because of the extent to which Aboriginal people are over-represented among injection drug using populations (9) as well as their reported lower access to substitution treatment compared to non-Aboriginal people. (10) For example in Vancouver, 26.6% of the people attending the supervised injection facility self-identify as being an Aboriginal person (Metis, First Nations, Inuit, Status or non-Status Indian).10 In the same cohort, 4.7% of Aboriginal participants reported the use of methadone compared to 12.9% of non-Aboriginal (the difference was statistically significant).

In a randomized clinical trial, (8) we compared the effectiveness of injectable diacetylmorphine or hydromorphone with optimized methadone maintenance treatment (MMT) in the treatment of long-term opioid-dependent individuals. In the present analysis, we examine the response to heroin-assisted treatment (HAT) among Aboriginal people. To our knowledge, this is the first such analysis.

METHODS

Data from an open-label randomized controlled trial conducted between March 2005 and July 2008 in Vancouver and Montreal, Canada, involving 251 participants were used. This study has been described in full detail elsewhere. (8,11,12) Briefly, patients were randomly assigned to receive oral methadone (n=111), injectable diacetylmorphine (n=115) or injectable hydromorphone (n=25) for a period of 12 months. The injectable drugs were provided in double-blind fashion. Treatments were provided following Canadian Best Practices guidelines. (13)

Analyses were performed only for the Vancouver site (n=192), since no Aboriginal participants were recruited at the Montreal site. Primary outcomes among Aboriginal and non-Aboriginal participants were a) retention in addiction treatment at 12 months, and b) response to treatment based on the European Addiction Severity Index. (14) Rate ratios and 95% confidence intervals were calculated, and analyses were on an intention-to-treat basis. Participants with missing values (only 5%) were considered not retained and non-responders.

RESULTS

Of the 192 participants at the Vancouver site, 60 (31.3%) self-identified as Aboriginal. Baseline profiles showed no differences between Aboriginal (n=60) and non-Aboriginal (n=132) people in the majority of baseline variables evaluated. However, Aboriginal people reported better housing and higher HIV infection rates compared to non-Aboriginal individuals.

After excluding each participant's initial 90 days of dose adjustment, the average daily dosage of diacetylmorphine and hydromorphone received by Aboriginal participants was 419.4 mg and 155.5 mg, respectively, compared to 414.4 mg and 221.3 mg, respectively, among non-Aboriginal participants, when prescribed alone. Aboriginal and non-Aboriginal participants who were prescribed MMT alone received mean daily doses of 92.5 mg and 97.3 mg, respectively.

Among Aboriginal participants in the injection and methadone groups, retention rates at 12 months were 84.4% vs. 57.1% (statistically significant) and response rates were 68.8% vs. 53.4%, respectively. Among non-Aboriginal participants, retention in injection compared to methadone was 90.7% vs. 50.9% and response was 66.7% vs. 43.9% (both significant). Aboriginal and non-Aboriginal rates were not significantly different.

DISCUSSION

The aim of this study was to evaluate the profile and response of Aboriginal participants in the NAOMI study. Among this group, treatment with injectable diacetylmorphine or hydromorphone was more effective than optimized MMT. In addition, there were no differences between Aboriginal and non-Aboriginal people in their baseline profile (except with respect to HIV prevalence) nor in their response to treatment. Moreover, Aboriginal people showed MMT retention rates higher than population-based rates in BC. (15)

Aboriginal people are over-represented among those who are severely affected by heroin addiction. The evidence of HAT effectiveness among Aboriginal participants in this study has important implications related to a) their reported lower access to substitution treatment compared to non-Aboriginal people (10) and b) their higher vulnerability for HIV infection, (16) consistent with their higher HIV rates in this study. Access and retention in substitution treatment is associated with a reduction in drug-related HIV-transmission risk behaviour. (17) Therefore, the higher retention rate in the HAT group is a key factor considering the high rates of HIV among Aboriginal people injecting drugs when compared to non-Aboriginal injecting drug users.

Offering medically prescribed diacetylmorphine or hydromorphone to Aboriginal people with severe long-term opioid dependence could be an effective means of attracting and retaining them in treatment, reducing the risk of HIV infection, and facilitating the provision of antiretroviral treatment for those already infected.

Acknowledgements: The NAOMI trial was funded through an operating grant from the Canadian Institutes of Health Research with additional support from the Canada Foundation for Innovation, the Canada Research Chairs Program, the University of British Columbia, Providence Health Care, the University of Montreal, Centre de Recherche et Aide aux Narcomanes, the Government of Quebec, Vancouver Coastal Health Authority and the BC Centre for Disease Control. The authors acknowledge the dedication of N. Laliberte, C. Gartry, K. Sayers, P-A Guevremont, P. Schneeberger, J. Chettiar, K. Lock, J. Lawlor, P. Pelletier, S. Maynard, M-I. Turgeon, G. Brunelle, A. Chan, S. MacDonald, T. Corneil, J. Geller, S. Jutha, S. Chai, M. Piacsezna, S. Sizto, the many remaining staff and members of the DSMB (A. Marlatt, N. El-Guebaly, J. Raboud, D. Roy). The authors also recognize the many US and Canadian (J. Rehm, B. Fischer) scientists who contributed to the early design discussions but ultimately were unable to participate in the trial. Most importantly, the authors acknowledge and thank the NAOMI trial participants.

Received: November 3, 2009

Accepted: January 23, 2010

REFERENCES

(1.) Gibson DR, Brand R, Anderson K, Kahn JG, Perales D, Guydish J. Two- to six-fold decreased odds of HIV risk behavior associated with use of syringe exchange. J Acquir Immune Defic Syndr 2002;31:237-42.

(2.) Termorshuizen F, Krol A, Prins M, van Ameijden EJ. Long-term outcome of chronic drug use: The Amsterdam Cohort Study among Drug Users. Am J Epidemiol 2005;161:271-79.

(3.) Brugal MT, Domingo-Salvany A, Puig R, Barrio G, Garcia de Olalla P, de la Fuente L. Evaluating the impact of methadone maintenance programmes on mortality due to overdose and AIDS in a cohort of heroin users in Spain. Addiction 2005;100:981-89.

(4.) van den Brink W, Hendriks VM, Blanken P, Koeter MW, van Zwieten BJ, van Ree JM. Medical prescription of heroin to treatment resistant heroin addicts: Two randomised controlled trials. BMJ 2003;327:310.

(5.) Rehm J, Gschwend P, Steffen T, Gutzwiller F, Dobler-Mikola A, Uchtenhagen A. Feasibility, safety, and efficacy of injectable heroin prescription for refractory opioid addicts: A follow-up study. Lancet 2001;358:1417-23.

(6.) March JC, Oviedo-Joekes E, Perea-Milla E, Carrasco F. Controlled trial of prescribed heroin in the treatment of opioid addiction. J Subst Abuse Treat 2006;31:203-11.

(7.) Haasen C, Verthein U, Degkwitz P, Berger J, Krausz M, Naber D. Heroin-assisted treatment for opioid dependence: Randomised controlled trial. Br J Psychiatry 2007;191:55-62.

(8.) Oviedo-Joekes E, Brissette S, Marsh DC, Lauzon P, Guh D, Anis A, et al. Diacetylmorphine versus methadone for the treatment of opioid addiction. N Engl J Med 2009;361:777-86.

(9.) PHAC. HIV/AIDS Among Aboriginal Peoples in Canada: A continuing concern. HIV/AIDS Epi Update. Centre for Infectious Disease Prevention and Control, Public Health Agency of Canada, 2006.

(10.) Kerr T, Marsh D, Li K, Montaner J, Wood E. Factors associated with methadone maintenance therapy use among a cohort of polysubstance using injection drug users in Vancouver. Drug Alcohol Depend 2005;80:329-35.

(11.) Oviedo-Joekes E , Nosyk B, Marsh D, Guh D, Brissette S, Gartry C, et al. Scientific and political challenges in North America's first randomized controlled trial of heroin-assisted treatment for severe heroin addiction: Rationale and design of the NAOMI Study. Clinical Trials 2009;6:261-71.

(12.) Oviedo-Joekes E , Nosyk B, Brissette S, Chettiar J, Schneeberger P, Marsh DC, et al. The North American Opiate Medication Initiative (NAOMI): Profile of Participants in North America's First Trial of Heroin-Assisted Treatment. J Urban Health 2008;85:812-25.

(13.) Health Canada. Best practices in methadone maintenance treatment. Ottawa, ON: Minister of Public Works and Government Services Canada, 2002.

(14.) Kokkevi A, Hartgers C. EuropASI: European adaptation of a multidimensional assessment instrument for drug and alcohol dependence. Eur Addict Res 1995;1:208-10.

(15.) Nosyk B, MacNab YC, Sun H, Fischer B, Marsh DC, Schechter MT, et al. Proportional hazards frailty models for recurrent methadone maintenance treatment. Am J Epidemiol 2009;170:783-92.

(16.) Craib KJ, Spittal PM, Wood E, Laliberte N, Hogg RS, Li K, et al. Risk factors for elevated HIV incidence among Aboriginal injection drug users in Vancouver. CMAJ2003;168:19-24.

(17.) Gowing L, Farrell M, Bornemann R, Ali R. Substitution treatment of injecting opioid users for prevention of HIV infection. Cochrane Database Syst Rev 2004;CD004145.

Eugenia Oviedo-Joekes, PhD, [1,2] Daphne Guh, MSc, [2] David C. Marsh, MD, [1-5] Suzanne Brissette, MD, [6] Bohdan Nosyk, PhD, [2] Michael Krausz, PhD, [2,3] Aslam Anis, PhD, [1,2] Wayne M. Christian, [7] Patricia Spittal, PhD, [1,2] Martin T. Schechter, PhD [1,2]

Author Affiliations

[1.] School of Population and Public Health, University of British Columbia, Vancouver, BC

[2.] Centre for Health Evaluation & Outcome Sciences, Providence Health Care, Vancouver, BC

[3.] Department of Psychiatry, University of British Columbia, Vancouver, BC

[4.] Vancouver Coastal Health & Providence Health Care, Vancouver, BC

[5.] Centre for Addiction Research BC, University of Victoria, Victoria, BC

[6.] Centre Hospitalier de l'Universite de Montreal, Montreal, QC

[7.] Chief, Splats'in/Secwepemc Nation, Enderby, BC

Correspondence: Eugenia Oviedo-Joekes, St. Paul's Hospital, 620-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Tel: 604-682-2344, ext. 62973, Fax: 604-806-8210, E-mail: eugenia@mail.cheos.ubc.ca

Funding: The study is funded by the Canadian Institutes of Health Research (CIHR).

Conflict of Interest: None to declare.
Table 1.  Aboriginal and Non-Aboriginal Participants' Profile
Comparisons at Baseline

                                          Aboriginal (n=60)
Socio-demographic
  Age--years                             41.38 [+ or -] 8.30
  Male--n (%)                                 31 (51.7)
  School education--years                10.33 [+ or -] 1.81
  Precarious housing--n (%)                   49 (81.7)
  Sexually or physically
    abused in life--n (%)                     26 (43.3)
  Money from illegal
    activities prior month--n (%)             47 (78.3)
Health
  Overdoses in the past                   3.02 [+ or -] 3.33
  Ever attempted suicide--n (%)               18 (30.0)
  Hepatitis C positive--n (%)                 52 (86.7)
  HIV positive--n (%)                         14 (23.3)
  Previous drug treatments               10.17 [+ or -] 11.11
  Previous MMT                            2.88 [+ or -] 1.56
Past drug use (years)
  Injecting drugs                        17.38 [+ or -] 9.24
  Heroin regular use in life             13.50 [+ or -] 7.74
  Illicit opioids
    regular use in life                   5.67 [+ or -] 7.23
  Cocaine regular use in life            12.10 [+ or -] 7.60
  Cannabis regular use in life           11.65 [+ or -] 12.48
Current drug use (days)
  Heroin use prior month                 28.08 [+ or -] 4.71
  Illicit opioids use prior month        9.43 [+ or -] 11.78
  Cocaine use prior month                18.98 [+ or -] 12.35
  Cannabis use prior month               6.33 [+ or -] 10.25

                                    Non-Aboriginal (n=132)   p-value
Socio-demographic
  Age--years                         40.70 [+ or -] 8.13      0.598
  Male--n (%)                             87 (65.9)           0.060
  School education--years            10.74 [+ or -] 2.17      0.175
  Precarious housing--n (%)               121 (91.7)          0.044
  Sexually or physically
    abused in life--n (%)                 61 (46.2)           0.710
  Money from illegal
    activities prior month--n (%)         94 (71.2)           0.300
Health
  Overdoses in the past               3.77 [+ or -] 7.31      0.331
  Ever attempted suicide--n (%)           38 (28.8)           0.864
  Hepatitis C positive--n (%)             104 (78.8)          0.195
  HIV positive--n (%)                      11 (8.3)           0.004
  Previous drug treatments           11.44 [+ or -] 11.81     0.472
  Previous MMT                        3.12 [+ or -] 1.79      0.352
Past drug use (years)
  Injecting drugs                    17.42 [+ or -] 10.58     0.978
  Heroin regular use in life         14.41 [+ or -] 8.52      0.467
  Illicit opioids
    regular use in life               6.02 [+ or -] 8.44      0.765
  Cocaine regular use in life        12.58 [+ or -] 8.02      0.689
  Cannabis regular use in life       13.02 [+ or -] 11.73     0.476
Current drug use (days)
  Heroin use prior month             26.81 [+ or -] 7.08      0.143
  Illicit opioids use prior month    10.50 [+ or -] 11.48     0.559
  Cocaine use prior month            18.57 [+ or -] 11.83     0.827
  Cannabis use prior month           6.19 [+ or -] 10.80      0.929

[+ or -] Standard Deviation

Table 2. Retention and Response in Treatment by Treatment
Group and Ethnicity at 12 Months

                                           HAT

                              Aboriginal        Non-Aboriginal
                                (n=32)              (n=75)
a) Retention in
        addiction
        treatment--n (%)   27 (84.4)         68 (90.7)
      NAOMI HAT--n (%)     22 (81.5)         53 (77.9)
      NAOMI MMT--n (%)     3 (11.1)          12 (17.6)
      Other MMT--n (%)     2 (7.4)           1 (1.5)
      Other
        treatments--n (%)  --                1 (1.5)
      Abstinence--n (%)    --                1 (1.5)
  Aboriginal vs.
     Non-Aboriginal *      0.93 (0.79, 1.10) (p=0.35)
   HAT vs. MMT *
      Aboriginal                             1.48 (1.04, 2.10) (p=0.02)
      Non-Aboriginal                         1.78 (1.37, 2.32) (p<0.001)
b) Clinical
        response--n (%)    22 (68.8)         50 (66.7)
      Drug response alone  7 (31.8)          15 (30.0)
      Legal response
        alone              2 (9.1)           1 (2.0)
      Both drug and
        legal response     13 (59.1)         34 (68.0)
   Aboriginal vs.
      Non-Aboriginal *     1.03 (0.78, 1.37) (p=0.83)
   HAT vs. MMT *
      Aboriginal                             1.28 (0.85, 1.95) (p=0.23)
      Non-Aboriginal                         1.52 (1.09, 2.12) (p=0.009)

                                         MMT

                              Aboriginal        Non-Aboriginal
                                (n=28)              (n=57)
a) Retention in

        addiction
        treatment--n (%)   16 (57.1)         29 (50.9)
      NAOMI HAT--n (%)     --                --
      NAOMI MMT--n (%)     12 (75.0)         22 (75.9)
      Other MMT--n (%)     3 (18.8)          7 (24.1)
      Other
        treatments--n (%)  --                --
      Abstinence--n (%)    1 (6.3)           --
  Aboriginal vs.
     Non-Aboriginal *      1.12 (0.75, 1.69) (p=0.59)
   HAT vs. MMT *
      Aboriginal
      Non-Aboriginal
b) Clinical
        response--n (%)    15 (53.4)         25 (43.9)
      Drug response alone  2 (13.3)          8 (32.0)
      Legal response
        alone              1 (6.7)           4 (16.0)
      Both drug and
        legal response     12 (80.0)         13 (52.0)
   Aboriginal vs.
      Non-Aboriginal *     1.22 (0.78, 1.92) (p=0.40)
   HAT vs. MMT *
      Aboriginal
      Non-Aboriginal

HAT= Heroin/Hydromorphone-assisted treatment, injectable; MMT=
methadone maintenance treatment.

a) Retention in treatment: treatment status at 12 months; Other MMT
refers to patients being prescribed methadone but not by the trial
doctors

b) Clinical response at 12 months: response to treatment based on the
European Addiction Severity Index.

* Relative risk (95% confidence interval).
COPYRIGHT 2010 Canadian Public Health Association
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2010 Gale, Cengage Learning. All rights reserved.

 
Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:QUANTITATIVE RESEARCH
Author:Oviedo-Joekes, Eugenia; Guh, Daphne; Marsh, David C.; Brissette, Suzanne; Nosyk, Bohdan; Krausz, Mic
Publication:Canadian Journal of Public Health
Article Type:Report
Geographic Code:1CANA
Date:May 1, 2010
Words:2451
Previous Article:Sustained intra- and interjurisdictional transmission of tuberculosis within a mobile, multi-ethnic social network: lessons for tuberculosis...
Next Article:A systematic literature review on response rates across racial and ethnic populations.
Topics:

Terms of use | Privacy policy | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters