Research paper
Directly observed therapy programmes for anti-retroviral treatment amongst injection drug users in Vancouver: Access, adherence and outcomes

https://doi.org/10.1016/j.drugpo.2006.11.009Get rights and content

Abstract

The introduction of highly active anti-retroviral therapy (HAART) has produced dramatic reductions in HIV associated morbidity and mortality. However, this success has not been replicated amongst injection drug users (IDUs) and other marginalised groups largely due to reduced uptake and lower rates of access and adherence to anti-retrovirals (ARVs). Multi-disciplinary programmes have been developed to help support ARV treatment and HIV care amongst IDUs. We retrospectively analysed the rates of adherence and plasma viral load suppression amongst participants in two clinic-based programmes that began enrollment in 1998. Of the 297 clients, the mean age was 40.5 years, 73% were males, 44% were of Aboriginal ethnicity, and 85% were Hepatitis C co-infected. One hundred and forty-two (47%) started therapy with a CD4 count below 200 mm−3, and baseline plasma viral load was over 100,000 copies/ml in 73 (25%). Treatment interruptions of greater than 2 weeks occurred in 41% of the participants during follow-up. The overall rate of adherence to treatment was 84.5% during periods when known interruptions were not considered. Plasma viral load suppression was attained by 29% during the first ARV regimen, although 83% had at least one fully suppressed plasma viral load recorded during follow-up. All cause mortality was 21% during the period of observation. The programmes initiated in Vancouver demonstrate the positive impact that a comprehensive DOT programme can have on ARV adherence, as well as highlight the challenges that remain.

Introduction

Dramatic reductions in HIV associated morbidity and mortality can be attributed to the effectiveness of highly active anti-retroviral therapy (HAART) (Hogg et al., 1999, Porter et al., 2003). However, this success has not been replicated amongst injection drug users (IDUs) and other marginalised groups due to reduced uptake and lower rates of adherence to treatment (Palepu et al., 2003; Shannon, Bright, Duddy, & Tyndall, 2005; Strathdee, Palepu, et al., 1998; Wood et al., 2003). Ongoing injection drug use, especially cocaine injection, has been shown to be strongly associated with reduced adherence to anti-retrovirals (ARVs) (Arnsten et al., 2002, Vlahov et al., 2005, Wood et al., 2004). Although many HIV positive IDUs have good therapeutic outcomes on ARVs and a number of existing programmes have contributed to improvements in health status, success at a population level remains elusive (Carrieri et al., 2003; Cohen, Wu, & Farley, 2004; Strathdee, van Ameijden, et al., 1998; Vlahov et al., 2005). Concurrent treatment for addictions, such as methadone maintenance therapy, has been shown to play an important role in increasing ARV adherence but this is not available in all settings and treatment for opiate addiction only captures a proportion of IDUs (Lucas, Flexner, & Moore, 2002; Palepu et al., 2006; Sambamoorthi, Warner, Crystal, & Walkup, 2000). In addition, there are some reports that IDUs may have reduced immunologic outcomes to ARVs despite complete viral suppression (Dronda et al., 2004).

In the Province of British Columbia, where ARVs are supplied free of charge, it was shown that between 1995 and 2001, 33% of deaths due to HIV/AIDS occurred in those who had never received ARVs (Wood et al., 2003). Uptake and adherence to therapy amongst marginalised groups is impeded by a range of structural, social and psychological factors and therefore a comprehensive approach to treatment is needed to optimise therapeutic outcomes (Howard et al., 2002, Knowlton et al., 2006, Moss et al., 2004, Wohl et al., 2006; Wood, Kerr, et al., 2006). HIV programmes that employ directly observed treatment (DOT) for ARVs have been developed and found to be a useful model to increase adherence to HIV medications (Bangsberg, Mundy, & Tulsky, 2001; Conway et al., 2004, McCance-Katz et al., 2002). This approach is also very conducive to monitoring co-morbidities, toxicities, and outcomes and the long-term engagement of the clients may also promote entry into addiction treatment (Altice et al., 2004).

An explosive HIV epidemic amongst IDUs occurred in the Downtown Eastside (DTES) of Vancouver during the 1990s and the prevalence of HIV amongst IDUs in this community is over 25% (Strathdee et al., 1997, Tyndall et al., 2003). It is estimated that there are over 5000 injection drug users in the 10 square city blocks that make up the DTES and there have been over 6000 different individuals who have used the local supervised injection facility that was opened in September 2003 (Spittal et al., 2002, Tyndall et al., 2005). The disparities in health care utilisation and HIV infections in this community are especially apparent amongst women and people of Aboriginal ethnicity (Craib et al., 2003, Spittal et al., 2002). It is known that large numbers of marginalised women are not accessing services of any kind and the uptake of ARV therapy is limited in this community and elsewhere (Shannon et al., 2005, Solomon et al., 1998).

In response to the increasing numbers of individuals requiring ARV therapy and the challenges of access and adherence, support programmes geared towards people with addictions have been developed. The aim of this paper is to measure ARV access, adherence and outcomes amongst illicit drug users from two programmes located in the DTES of Vancouver.

Section snippets

HIV/AIDS drug treatment programme

In the province of British Columbia, ARVs are distributed free of charge to all eligible HIV infected individuals through the BC Centre for Excellence in HIV/AIDS Drug Treatment Programme (DTP). The guidelines for this distribution are determined by the Therapeutic Guidelines Committee and are consistent with the recommendations put forward by the International AIDS Society, USA. Plasma viral load testing is collected within the DTP and for the purpose of this study, we used a viral load result

Results

Table 1 shows the characteristics for the 297 clients who received ARVs stratified by the two clinic sites. The mean age at enrollment was 40.5 years, 73% were males, and 44% were of Aboriginal ethnicity. The mean CD4 count at baseline was 248 cells/mm3, with 142 (47%) starting therapy with a CD4 count below 200 cells/mm3. The plasma viral load at the beginning of therapy was over 100,000 copies/ml in 73 (25%). Hepatitis C co-infection was present in 85% of participants based on a positive

Discussion

The two ARV support programmes evaluated in this study demonstrate the relatively high rates of adherence and viral load suppression that can be achieved through comprehensive supportive programmes. It also illustrates the frequency of treatment interruptions and the extremely high mortality rates observed in programme participants. Those who started ARVs with CD4 counts below 200 cells/mm3 had higher mortality rates.

Through detailed daily records of ARV dispensing and observed ingestion we were

Acknowledgements

The authors wish to thank Shelly Dean, the clinic staff and the participants at the MAT Programme and Doreen Littlejohn, the clinic staff and participants at the Positive Outlook Programme. Dr. Tyndall is supported by the Michael Smith Foundation for Health Research. Dr. Kerr is supported by the Michael Smith Foundation for Health Research and the Canadian Institutes for Health Research.

References (45)

  • D.R. Bangsberg et al.

    Expanding directly observed therapy: Tuberculosis to human immunodeficiency virus

    American Journal of Medicine

    (2001)
  • U. Sambamoorthi et al.

    Drug abuse, methadone treatment, and health services use among injection drug users with AIDS

    Drug and Alcohol Dependence

    (2000)
  • E. Wood et al.

    Slower uptake of HIV anti-retroviral therapy among Aboriginal injection drug users

    The Journal of Infection

    (2006)
  • C. Aceijas et al.

    Anti-retroviral treatment for injecting drug users in developing and transitional countries 1 year before the end of the “Treating 3 million by 2005. Making it happen. The WHO strategy” (“3 by 5”)

    Addiction

    (2006)
  • F.L. Altice et al.

    Developing a directly administered anti-retroviral therapy intervention for HIV-infected drug users: Implications for program replication

    Clinical Infectious Diseases

    (2004)
  • J.H. Arnsten et al.

    Impact of active drug use on anti-retroviral therapy adherence and viral suppression in HIV-infected drug users

    Journal of General Internal Medicine

    (2002)
  • D.R. Bangsberg

    Less than 95% adherence to nonnucleoside reverse-transcriptase inhibitor therapy can lead to viral suppression

    Clinical Infectious Diseases

    (2006)
  • D.R. Bangsberg et al.

    High levels of adherence do not prevent accumulation of HIV drug resistance mutations

    AIDS

    (2003)
  • M.P. Carrieri et al.

    Failure to maintain adherence to HAART in a cohort of French HIV-positive injecting drug users

    International Journal of Behavioural Medicine

    (2003)
  • D.A. Cohen et al.

    Comparing the cost-effectiveness of HIV prevention interventions

    Journal of Acquired Immune Deficiency Syndrome

    (2004)
  • B. Conway et al.

    Directly observed therapy for the management of HIV-infected patients in a methadone program

    Clinical Infectious Diseases

    (2004)
  • K.J. Craib et al.

    Risk factors for elevated HIV incidence among Aboriginal injection drug users in Vancouver

    CMAJ

    (2003)
  • L. Ding et al.

    Predictors and consequences of negative physician attitudes toward HIV-infected injection drug users

    Archives of Internal Medicine

    (2005)
  • F. Dronda et al.

    CD4 cell recovery during successful anti-retroviral therapy in naive HIV-infected patients: The role of intravenous drug use

    AIDS

    (2004)
  • R. Gross et al.

    A simple, dynamic measure of anti-retroviral therapy adherence predicts failure to maintain HIV-1 suppression

    The Journal of Infectious Diseases

    (2006)
  • S.M. Hammer et al.

    Treatment for adult HIV infection: 2006 recommendations of the International AIDS Society-USA panel

    JAMA

    (2006)
  • P.R. Harrigan et al.

    Predictors of HIV drug-resistance mutations in a large anti-retroviral-naive cohort initiating triple anti-retroviral therapy

    The Journal of Infectious Diseases

    (2005)
  • R.S. Hogg et al.

    Improved survival among HIV-infected patients after initiation of triple-drug anti-retroviral regimens [see comments]

    CMAJ

    (1999)
  • A.A. Howard et al.

    A prospective study of adherence and viral load in a large multi-center cohort of HIV-infected women

    AIDS

    (2002)
  • A. Knowlton et al.

    Individual, interpersonal, and structural correlates of effective HAART use among urban active injection drug users

    Journal of Acquired Immune Deficiency Syndrome

    (2006)
  • R. Kohli et al.

    Mortality in an urban cohort of HIV-infected and at-risk drug users in the era of highly active anti-retroviral therapy

    Clinical Infectious Diseases

    (2005)
  • A. Loughlin et al.

    Provider barriers to prescribing HAART to medically-eligible HIV-infected drug users

    AIDS Care

    (2004)
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