{
  "abstract": "Introduction Opioid agonist treatment (OAT) prescribing patterns have shifted in recent years in British Columbia (BC), Canada due to the increasingly toxic unregulated drug supply. Experimental evidence to support guidelines on the effectiveness of maintaining clients at different maintenance dosage levels is incomplete and outdated for the fentanyl era. Our objective is to assess the risk of treatment discontinuation and mortality among individuals receiving different maintenance dosage strategies for OAT with methadone, buprenorphine/naloxone or slow-release oral morphine (SROM) at the population level in BC, Canada.Methods and analysis We propose a retrospective population-level study of BC residents initiating OAT on methadone, buprenorphine/naloxone or SROM between 1 January 2010 and 31 December 2022 who were ≥18 years of age with no known pregnancy, no history of cancer diagnosis or receiving palliative care and not currently incarcerated. Our study will employ health administrative databases linked at the individual level to emulate a target trial per OAT type where individuals will be assigned to discrete maintenance dosing strategies, according to the full range observed in BC during the study period. Primary outcomes include treatment discontinuation and all-cause mortality. To determine the effectiveness of alternative maintenance doses, we will emulate a ‘per-protocol’ trial using a clone-censor-weight approach to adjust for measured time-dependent confounding by indication.Ethics and dissemination The protocol, cohort creation and analysis plan have been classified and approved as a quality improvement initiative by Providence Health Care Research Ethics Board and the Simon Fraser University Office of Research Ethics. All data are deidentified, securely stored and accessed in accordance with provincial privacy regulations. Results will be disseminated and shared with local advocacy groups and decision-makers, developers of national and international clinical guidelines, presented at national and international conferences and published in peer-reviewed journals electronically and in print.",
  "authors": [
    {
      "affiliations": [
        "Centre for Advancing Health Outcomes, Providence Health Care, Vancouver, British Columbia, Canada"
      ],
      "name": "Michelle Zanette"
    },
    {
      "affiliations": [
        "Centre for Advancing Health Outcomes, Providence Health Care, Vancouver, British Columbia, Canada"
      ],
      "name": "Jeong Eun Min"
    },
    {
      "affiliations": [
        "Centre for Advancing Health Outcomes, Providence Health Care, Vancouver, British Columbia, Canada"
      ],
      "name": "Fahmida Homayra"
    },
    {
      "affiliations": [
        "Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada",
        "Department of Medicine, St Paul’s Hospital, Vancouver, British Columbia, Canada",
        "British Columbia Centre on Substance Use, Vancouver, British Columbia, Canada"
      ],
      "name": "Paxton Bach"
    },
    {
      "affiliations": [
        "British Columbia Centre on Substance Use, Vancouver, British Columbia, Canada"
      ],
      "name": "M Eugenia Socías"
    },
    {
      "affiliations": [
        "Centre de Recherche, Centre Hospitalier de l’Université de Montréal, Montreal, Québec, Canada",
        "Department of Family Medicine and Emergency Medicine, University of Montreal, Montreal, Québec, Canada"
      ],
      "name": "Julie Bruneau"
    },
    {
      "affiliations": [
        "Department of Medicine, Oregon Health & Science University, Portland, Oregon, USA",
        "School of Public Health, Oregon Health & Science University-Portland State University, Portland, Oregon, USA"
      ],
      "name": "P Todd Korthuis"
    },
    {
      "affiliations": [
        "Centre for Advancing Health Outcomes, Providence Health Care, Vancouver, British Columbia, Canada",
        "School of Population and Public Health, UBC, Vancouver, British Columbia, Canada"
      ],
      "name": "Ehsan Karim"
    },
    {
      "affiliations": [
        "MRC Biostatistics Unit, University of Cambridge Institute of Public Health, Cambridge, UK"
      ],
      "name": "Shaun Seaman"
    },
    {
      "affiliations": [
        "Campbell Family Mental Health Research Institute",
        "Addictions Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada",
        "Family and Community Medicine, University of Toronto Faculty of Medicine, Toronto, Ontario, Canada"
      ],
      "name": "Nikki Bozinoff"
    },
    {
      "affiliations": [
        "British Columbia Centre on Substance Use, Vancouver, British Columbia, Canada",
        "School of Social Work, The University of British Columbia Okanagan, Kelowna, British Columbia, Canada"
      ],
      "name": "Mary Clare Kennedy"
    },
    {
      "affiliations": [
        "Centre for Advancing Health Outcomes, Providence Health Care, Vancouver, British Columbia, Canada",
        "Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada"
      ],
      "name": "Bohdan Nosyk"
    }
  ],
  "title": "Comparative effectiveness of maintenance doses of opioid agonist treatment among individuals with opioid use disorder: a target trial emulation protocol using a population-based observational study",
  "uid": "e835e596-2b65-57f7-ae76-9ca7309c8b0b"
}