Table 2 Eligibility criteria used to screen studies

Inclusion Criteria

For all studies:

• Includes findings on the impact of relaxed restrictions on take-home doses of opioid agonist medication for opioid use disorder, either alone or in conjunction with other interventions/exposures, during the Covid-19 pandemic on program effectiveness in opioid agonist treatment

• Written in English, French, Spanish, Portuguese, or Italian

For quantitative component:

• A randomized or non-randomized study reporting quantitative data OR a mixed methods study where the quantitative component can be cleanly extracted

• Assesses one or more of the following client outcomes: (1) Retention in treatment, using any quantitative measure; (2) illicit substance use, using any quantitative measure; (3) fatal and non-fatal overdose, using any quantitative measure; (4) client health, using any quantitative measure; (5) client quality of life, using any quantitative measure; (6) client satisfaction with treatment, using any quantitative measure

For qualitative component:

• A qualitative study using any qualitative approach (e.g., grounded theory, critical theory, ethnography) OR a mixed methods study where the qualitative component can be cleanly extracted

• Includes findings on OAT clients’ experiences with relaxed restrictions on take-home doses of OAT during the Covid-19 pandemic

Exclusion Criteria

For all studies:

• OAT clients are a subgroup of the study population, but findings specific to this group cannot be extracted;

• Take-home doses intended to be supervised remotely or in person (e.g., witnessed daily delivery; take-homes witnessed through videoconferencing systems)

• Commentaries, editorials, or letters to the editor, unless original empirical research is presented

• Conference abstracts, posters, or slide decks, unless meeting three predefined conditions designed to limit retrieval to relevant studies for which sufficient information can be obtained

• The study is a preprint that has become available in peer-reviewed form

For qualitative component:

• The study uses quantitative methods (e.g., questionnaires, fixed-choice surveys) to collect qualitative data