Abed 2019.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: parallel group
Participants	Substance: opioids Baseline characteristics Mindfulness‐based intervention Number randomized: 30 Control 1 Number randomized: 30 Overall Number randomized: 60 Included criteria: undergoing MMT, having at least 2 lapses during MMT Excluded criteria: none Number missing: 5 Reason missing: left the study Baseline differences: no differences Age: 36.6 Percent female: 0% Race/Ethnicity: 100% Iranian
Interventions	Intervention characteristics Mindfulness‐based intervention Group name: MBRP Theory: Witkiewitz et al. (2013) Duration: 8 weeks Timing: 1x week for 2 hours Delivery: group Providers: study first author Co‐intervention: methadone Integrity: not reported Compliance: not reported Control 1: no intervention Co‐intervention: methadone
Outcomes	Desire to use Outcome type: continuous outcome Reporting: fully reported Direction: lower is better Data value: endpoint Time point: post‐treatment Treatment acceptability (attrition) Outcome type: dichotomous outcome Reporting: fully reported Direction: lower is better Data value: endpoint Time point: post‐treatment
Identification	Sponsorship source: n/a Country: Iran Setting: not residential Authors name: Abed Institution: Islamic Azad University Email: mohammadrezaabed777@gmail.com Address: Department of Psychology, Najafabad Branch, Islamnic Azad University, Najafabad, Iran COI: none Diagnosis tool: received methadone maintenance treatment Diagnosis type: informal Funding: none reported Journal: Journal of Substance Abuse Publication type: published report Secondary publications: none
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding
Blinding of outcome assessment (detection bias) Treatment acceptability (attrition)	Low risk	Objective measure
Blinding of outcome assessment (detection bias) All non‐attrition outcomes	High risk	Self‐report outcomes
Incomplete outcome data (attrition bias) All outcomes	High risk	Attrition and higher attrition in MBI, used completer analysis
Selective reporting (reporting bias)	Unclear risk	No protocol available, no statement of primary outcome
Other bias: equivalence of baseline characteristics (selection bias)	Low risk	quote: "no differences in pre‐test scores" p. 640