Examining inequities in access to opioid agonist treatment (OAT) take-home doses (THD): A Canadian OAT guideline synthesis and systematic review

Background Daily supervised Opioid Agonist Treatment (OAT) medication has been identified as a barrier to treatment retention. Canadian OAT guidelines outline take-home dose (THD) criteria, yet, OAT prescribers use their clinical judgement to decide whether an individual is ‘clinically stable’ to receive THD. There is limited information regarding whether these decisions may result in inequitable access to THD, including in the context of updated COVID-19 guidance. The current Canadian OAT THD guideline synthesis and systematic review aimed to address this knowledge gap. Methods This systematic review included a two-pronged approach. First, we searched available academic literature in Embase, Medline, and PsychINFO up until October 12th, 2022, to identify studies that compared characteristics of individuals on OAT who had and had not been granted access to THD to explore potential inequities in access. Next, we identified all Canadian national and provincial OAT guidelines through a semi-structured grey literature search (conducted between September-October 2022) and extracted all THD ‘stability’ and allowances/timeline criteria to compare against characteristics identified in the literature search. Data from both review arms were synthesized and narratively presented. Results A total of n = 56 guidelines and n = 7 academic studies were included. The systematic review identified a number of patient characteristics such as age, sex, race/ethnicity, marital status, housing, employment, neighborhood income, drug use, mental health, health service utilization, as well as treatment duration that were associated with differential access to THD. The Canadian OAT THD guideline synthesis identified many of these same characteristics as ‘stability’ criteria, underscoring the potential for Canadian OAT guidelines to result in inequitable access to THD. Conclusions This two-pronged literature review demonstrated that current guidelines likely contribute to inequitable OAT THD access due primarily to inconsistent ‘stability’ criteria across guidelines. More research is needed to understand differential OAT THD access with a focus on prescriber decision-making and evaluating associated treatment and safety outcomes. The development of a client-centered, equity-focused, and evidence-informed decision making framework that incorporates more clear definitions of ‘stability’ criteria and indications for prescriber discretion is warranted.