Research Paper
The effect of Housing First on adherence to methadone maintenance treatment

https://doi.org/10.1016/j.drugpo.2018.03.012Get rights and content

Abstract

Background

Opioid overdose deaths have become a public health crisis in North America, and those who are homeless are particularly vulnerable. Methadone maintenance treatment (MMT) may prevent overdose and death among homeless people with opioid dependence, but suboptimal medication adherence is a common limitation. Previous research found that Housing First (HF) increases antipsychotic medication adherence among formerly homeless people. However, no experimental trials have examined whether HF has a significant impact on MMT adherence. We examined the intervention effect of HF on MMT adherence in a randomized sample of homeless adults experiencing mental illness and opioid dependence in Vancouver, Canada.

Methods

Comprehensive administrative and self-reported data from homeless adults living with serious mental illness recruited to the Vancouver At Home study were analyzed. Only methadone recipients were included (n = 97). The medication possession ratio (MPR) was utilized as the measure of adherence, and relevant data were obtained from provincial administrative pharmacy records. Study arms were HF and treatment as usual (TAU). Student t-tests were used to test for differences in MMT MPR between HF and TAU.

Results

No significant differences were observed in MMT MPR between participants in HF and TAU (0.52 vs. 0.57, p = 0.559) in the post-randomization period.

Conclusion

HF was not associated with significantly different MMT MPR compared to TAU. Additional interventions are indicated as HF alone was insufficient to facilitate improved MMT adherence among formerly homeless adults experiencing concurrent opioid dependence and serious mental illness.

Introduction

Opioid overdose deaths have increased and become a public health crisis in communities across North America (British Columbia Coroners Service, 2017; Rudd, Aleshire, Zibbell, & Gladden, 2016; Ruhm, 2017). Homeless people are at particular risk for nonfatal drug overdose (Fischer et al., 2004), and opioid overdose is reported as a major cause of death in this population (Baggett et al., 2013). Methadone maintenance treatment (MMT) has been shown to reduce illicit opioid use (Gowing, Farrell, Bornemann, Sullivan, & Ali, 2011; Mattick, Breen, Kimber, & Davoli, 2009) and related mortality (Brugal et al., 2005; Caplehorn, Dalton, Haldar, Petrenas, & Nisbet, 1996; Huang et al., 2011; Langendam, van Brussel, Coutinho, & van Ameijden, 2001), although little research has examined the effectiveness of MMT among opioid-dependent homeless people.

Inconsistent adherence to MMT can be problematic, as this can increase susceptibility to overdose (Wolff, 2002). Preliminary analysis of MMT adherence in a Canadian sample of homeless and mentally ill adults found that methadone was taken on fewer than half of the days over an average 6.5–year period after initiating treatment (Parpouchi, Moniruzzaman, Rezansoff, Russolillo, & Somers, 2017). A treatment schedule requiring MMT patients to visit a pharmacy daily for witnessed ingestion of methadone has been found to be difficult for some patients (Anstice, Strike, & Brands, 2009) and may hence pose barriers to consistent adherence. Illicit opioid use during treatment has also been found to be associated with poorer adherence (Raffa et al., 2007), and researchers have argued that doses should be titrated rapidly during induction to increase the proportion of people experiencing abstinence from illicit opioid use during MMT (Trafton, Minkel, Humphreys, 2006). However, it is important to note that the highest risk of overdose during MMT is during the induction phase (Baxter et al., 2013), and titrating doses too quickly can lead to respiratory depression and death (Modesto-Lowe, Brooks, & Petry, 2010), so clinical practice guidelines should be consulted. Lower adherence to MMT has also been found to be associated with methadone doses below 60 mg (Shen et al., 2016).

Homelessness is recognized as a barrier to adherence to a variety of treatments involving medication (Hunter et al., 2015; Milloy et al., 2012; Sajatovic, Valenstein, Blow, Ganoczy, & Ignacio, 2006). Competing priorities, such as securing shelter and other basic necessities, can compromise access to health care (Gelberg, Gallagher, Andersen, & Koegel, 1997; Krausz et al., 2013) and continuity of prescribed medication (Hunter et al., 2015). The perception of discrimination from health practitioners (Wen, Hudak, & Hwang, 2007), as well as mental health and substance use problems (Krausz et al., 2013) may also negatively affect access to health care among homeless people. In response to studies reporting suboptimal MMT retention or adherence among homeless people, researchers have called for housing as part of the solution (Appel, Tsemberis, Joseph, Stefancic, & Lambert-Wacey, 2012; Lundgren, Sullivan, Maina, & Schilling, 2007; Parpouchi et al., 2017).

Existing research suggests that Housing First (HF) may promote medication adherence among formerly homeless people (Appel et al., 2012; Rezansoff et al., 2017). HF includes the provision of housing, health care, and social supports, with no requirement of treatment or abstinence (Tsemberis, Gulcur, & Nakae, 2004; Tsemberis, 1999). Appel et al. (2012) investigated the effect of HF on MMT retention among homeless and mentally ill methadone patients who had recent involvement with the criminal justice system. Three years post-implementation, MMT retention was significantly higher among participants who received HF compared to the comparison group (52% vs. 20%). However, the study had important limitations; a randomized controlled trial (RCT) design was not used, and there were differences in the inclusion criteria for membership in the two groups. Moreover, the study measured treatment retention rather than medication adherence. It is thus unclear whether HF is responsible for increased MMT adherence. Using an experimental design, Rezansoff et al. (2017) found that when compared to “usual care” HF was associated with significantly higher adherence to antipsychotic medication among homeless adults diagnosed with schizophrenia. Experimental research is needed to determine whether HF has a similar effect on adherence to other drugs, including methadone.

The current study is the first randomized trial to examine the effect of HF on MMT adherence among homeless adults living with serious mental illness. We hypothesized that randomization to HF would be associated with significantly higher MMT adherence than randomization to treatment as usual (TAU).

Section snippets

Data sources and participant sampling

Data for the present study came from two randomized controlled trials (RCTs) which collectively comprise the Vancouver At Home (VAH) study (Current Controlled Trials: ISRCTN57595077 and ISRCTN66721740). The two trials investigated HF interventions among homeless adults (n = 497) experiencing serious mental illness in Vancouver, Canada (Somers et al., 2013). The current study was approved by the institutional ethics review board of Simon Fraser University.

A baseline interview was conducted

Results

Fig. 1 illustrates the flow of participants included in the current study. Of 497 participants randomized, 433 (87%) provided consent for access to their administrative data. PharmaNet data indicated that 97 of these individuals (22%) initiated MMT after January 1, 1996. The majority (n = 78) initiated MMT prior to randomization, while 19 initiated following randomization. Baseline participant characteristics for all MMT recipients are shown in Table 1.

There were no significant baseline

Discussion

No significant difference in MMT adherence was found between participants randomized to HF and those randomized to TAU. The estimated mean daily dose administered to participants during the pre and post-randomization periods (78.3 and 78.1 mg, respectively) was also well within the recommended range of 60–100 mg per day (Faggiano, Vigna-Taglianti, Versino, & Lemma, 2003) and did not differ significantly between HF and TAU. Our results contrast with previous findings suggesting that HF promotes

Conclusions

This study is the first to examine the impact of HF on adherence to MMT. Despite the many benefits of HF reported in existing literature, our findings suggest that it did not increase MMT adherence among homeless adults living with serious mental illness, when compared to TAU. Additional supports and resources are needed to achieve continuous engagement in opioid agonist treatment, as reflected by medication adherence.

Funding

Vancouver At Home was supported by the Mental Health Commission of Canada (Grant Number: 2009s0124). MP is a 2017 Pierre Elliott Trudeau Foundation Scholar. MP (Funding Reference Number: GSD-146191), SNR (Funding Reference Number: MFE-148262), and AR (Funding Reference Number: GSD-146208) are each funded by the Canadian Institutes of Health Research. The Mental Health Commission of Canada required an experimental design but had no role in the collection, analysis or interpretation of the data,

Declarations of interest

None.

Acknowledgements

We are grateful for the invaluable contribution of participants and the service and research teams of the Vancouver At Home study. We also thank the British Columbia Inter-Ministry Research Initiative.

References (50)

  • British Columbia Coroners Service

    Illicit drug overdose deaths in BC january 1, 2007–June 30, 2017

    (2017)
  • R.K. Brooner et al.

    Using behavioral reinforcement to improve methadone treatment participation

    Science & Practice Perspectives

    (2002)
  • M.T. Brugal et al.

    Evaluating the impact of methadone maintenance programmes on mortality due to overdose and AIDS in a cohort of heroin users in Spain

    Addiction

    (2005)
  • J.R.M. Caplehorn et al.

    Methadone maintenance and addicts’ risk of fatal heroin overdose

    Substance Use & Misuse

    (1996)
  • College of Physicians and Surgeons of British Columbia

    Methadone and buprenorphine: Clinical practice guideline for opioid use disorder

    (2016)
  • F. Faggiano et al.

    Methadone maintenance at different dosages for opioid dependence

    Cochrane Database of Systematic Reviews

    (2003)
  • B. Fischer et al.

    Determinants of overdose incidents among illicit opioid users in 5 Canadian cities

    Canadian Medical Association Journal

    (2004)
  • L. Gelberg et al.

    Competing priorities as a barrier to medical care among homeless adults in Los Angeles

    American Journal of Public Health

    (1997)
  • Government of British Columbia

    PharmaCare for B.C. residents

    (2017)
  • Government of British Columbia

    PharmaNet

    (2017)
  • Government of British Columbia

    Vital statistics

    (2017)
  • L. Gowing et al.

    Oral substitution treatment of injecting opioid users for prevention of HIV infection

    Cochrane Database of Systematic Reviews

    (2011)
  • J. Hettema et al.

    Motivational interviewing

    Annual Review of Clinical Psychology

    (2005)
  • Y.F. Huang et al.

    Mortality among a cohort of drug users after their release from prison: An evaluation of the effectiveness of a harm reduction program in Taiwan

    Addiction

    (2011)
  • C.E. Hunter et al.

    Barriers to prescription medication adherence among homeless and vulnerably housed adults in three Canadian cities

    Journal of Primary Care & Community Health

    (2015)
  • Cited by (15)

    • A cohort study examining the relationship among housing status, patient characteristics, and retention among individuals enrolled in low-barrier-to-treatment-access methadone maintenance treatment

      2022, Journal of Substance Abuse Treatment
      Citation Excerpt :

      Multiple studies demonstrate the feasibility of low-demand or housing first—which do not require abstinence from substances for individuals to secure housing—as strategies to tackle homelessness in people with SUDs, with benefits to both the participants and the health care system (Appel et al., 2012; Davidson et al., 2014; Edens et al., 2011; Larimer et al., 2009; Padgett et al., 2006), including one study showing methadone treatment but not “detoxification” or inpatient treatment decreased discharge from supportive housing (Hall et al., 2020). While at least one study did not see differences in MMT adherence in a housing first intervention for patients with severe mental illness and OUD on MMT, more work should examine the effects of housing on patients with OUD (Parpouchi et al., 2018). Shelter-based provision of MOUD and mobile treatment facilities have also been shown to be efficacious at engaging patients experiencing homelessness and OUD in evidence-based treatment (Carter et al., 2019; Chatterjee et al., 2017; Hall et al., 2014; O'Gurek et al., 2021; Regis et al., 2020); further research should investigate the effects of these and other innovative programs (both as stand-alone interventions or in conjunction with low-barrier-to-treatment-access MMT programs) on promoting retention.

    • Harm reduction outcomes and practices in Housing First: A mixed-methods systematic review

      2021, Drug and Alcohol Dependence
      Citation Excerpt :

      Findings between two studies differed on retention in methadone maintenance treatment (MMT). A subgroup analysis from a randomized controlled trial in Vancouver, Canada, did not find differences in retention between Housing First and treatment as usual (Parpouchi et al., 2018), whereas an observational study by Appel et al. (2012) found that Housing First participants had significantly higher retention in MMT than a matched comparison group. Both studies had small sample sizes of fewer than 100 participants.

    • The association of opioid use disorder and homelessness nationally in the veterans health administration

      2021, Drug and Alcohol Dependence
      Citation Excerpt :

      Thus, the higher prevalence of multiple SUDs among homeless adults may at least partly explain the observed higher fatal and non-fatal overdose events among homeless adults as compared to the general population (Baggett et al., 2015; Doran et al., 2018). Multiple interventions may be needed to reduce the high incidence of opioid overdose deaths among homeless populations in American communities including overdose education and naloxone distribution (Langham et al., 2018; Wright et al., 2006), low threshold medication treatment for OUD (Carter et al., 2019), and permanent supportive housing (Chatterjee et al., 2018; Dyb, 2016; Parpouchi et al., 2017, 2018). It is widely believed that the regular use of particular substances such as heroin has a larger adverse impact on individual social and medical outcomes than other substances like cannabis (Nutt et al., 2007, 2010).

    View all citing articles on Scopus
    View full text