Table 1.

Summary of included study characteristics.

#	Author (Year)	Design	Location & clinical setting	Patient population & inclusion criteria	Sample size	Primary outcome measures
Psychosocial Interventions
1	Chawarski et al. (2008)	RCT	Muar, Malaysia Community-based outpatient center	No age data No gender data No race/ethnicity data. 100 % heroin dependent. Treatment seeking adults aged 18–65 who met DSM-IV criteria for opioid dependence and had an opioid positive urine toxicology test.	n = 24	Abstinence by UDT Self-reported days of drug use/week Maximum consecutive weeks abstinent from opioids
2	Fiellin et al. (2006)	RCT	Connecticut, US Primary care clinic, university hospital	Age: 36 23 % women 77 % white Individuals meeting the criteria for opioid dependence and opioid agonist treatment.	n = 166	Self-reported frequency of illicit opioid use Percentage of opioid-negative UDT Maximum number of consecutive weeks abstinent from opioids (self-report, UDT)
3	Fiellin et al. (2013)	RCT	Connecticut, US Primary care clinic, university hospital	Age: 33.7 26 % women 89 % white, 9% Hispanic Enrolled patients met criteria for opioid dependence.	n = 141	Self-reported frequency of illicit opioid use Maximum number of consecutive weeks of abstinence from opioids (self-report, UDT)
4	Galanter et al. (2004)	RCT	New York, US University medical center	Age: 36 (8.4) 24 % women 59 % white, 24 % Hispanic, 12 % Black, 5% Asian/other Adults aged 21–65 diagnosed as heroin dependent by DSM-IV criteria with a drug-free family member or friend who could support recovery.	n = 66	Percentage opiate-free UDT Last three UDTs negative for opioids
5	Ling et al. (2013)	RCT	Los Angeles, US Outpatient clinical research center	Age: 36.9 31 % women 42 % white, 10 % African American Eligible individuals were 15+, met DSM-IV-TR criteria for opioid dependence, in good medical and psychiatric health, not pregnant, no buprenorphine sensitivity, and no cooccurring SUD or unsafe benzodiazepine use.	n = 202	Opioid-free urine samples
6	Stein et al. (2015)	RCT	US Outpatient buprenorphine clinic	Age: 41.1 (11.3) 45 % women 86 % white Individuals 18–65 seeking buprenorphine treatment and planning to remain on buprenorphine for at least 3 months.	n = 49	Self-reported illicit opioid use in last 28 days of treatment UDT positive for opioids at each monthly assessment
7	Tetrault et al. (2012)	RCT	New Haven CT, US HIV primary care clinic, university hospital	Age: 46.9 (8.0) 17 % women 57 % white Patients who met DSM-IV criteria for opioid dependence, diagnosis of HIV infection, had aspartate transferase or alanine transferase values less than 5 times the upper limits of normal.	n = 47	Percentage opioid-negative UDT Self-reported duration of continuous opioid abstinence
8	Weiss et al. (2011)	RCT	CA, IN, MA, NY, OR, SC, WA, WV, US Outpatient treatment sites	Age: 33.2 (10.2) 40 % women 91 % white Treatment-seeking participants 18+, met DSM-IV criteria for dependence on prescription opioids.	n = 360	UDT confirmed self-report of opioid abstinence-success defined as abstinence from opioids during the final study week (week 12) as well as > = 2 of the 3 proceeding weeks
9	Bloom-Foster and Mehl-Madrona (2020)	Prospective, feasibility, single-group, cohort study	Bangor, Maine, US Outpatient family medicine teaching clinic	Age: 32.2 (7.2) 63 % women 95 % white Polysubstance 78 % Adult patients initiating buprenorphine-based outpatient treatment for opioid use disorder.	n = 40	Feasibility Acceptability Subjective usefulness to recovery
10	Brown et al. (2014)	Preliminary evaluation	Providence, Rhode Island, US Outpatient research setting	Age: 40.4 (9.74) 20 % women 2 white, 2 Hispanic, 1 Black Adults 18–65 initiating buprenorphine treatment and planning to remain on buprenorphine for at least three months.	n = 5	UDT negative for opioids Self-reported drug use Treatment effectiveness assessment General psychological acceptance-(Acceptance and Action Questionnaire-II) Avoidance specific to opioid use (Avoidance and Inflexibility Scale) Distress tolerance (Distress Tolerance Scale)
11	Montoya et al. (2005)	Secondary analysis RCT	Baltimore, MD, US Outpatient research clinic	Age: 33.7 (6.32) 28 % women 76 % Black Adults 21–50 with comorbid DSM-IIIR cocaine and opioid use dependence, self-reported use of cocaine and opioids within 14 days.	n = 90	Psychotherapy visit attendance Morphine urine levels BZE (cocaine metabolite) urine levels
12	Moore et al. (2012)	Two group non-randomized trial	US Primary care center, urban teaching hospital	Age: 38 years 25 % women 71 % white Met DSM-IV criteria for opioid dependence and qualified for opioid agonist maintenance treatment.	n = 58	Patient Retention Weeks of opioid abstinence Patient satisfaction
13	Moore et al. (2016)	Secondary analysis, RCT	Connecticut, US Primary care clinic	Age: 33.7 (SD) 26 % women 89 % White, 9% Hispanic Patients meeting the DSM-IV criteria for opioid dependence.	n = 140	UDT negative for opioids, all drugs Maximum consecutive weeks abstinent Addiction Severity Index Retention (study completion, weeks remaining in treatment)
14	Weiss et al. (2014)	Secondary analysis, RCT	CA, IN, MA, NY, OR, SC, WA, WV, US Outpatient treatment sites	Age: 35.2 (9.7) 42 % women 91 % white Treatment-seeking participants who met DSM-IV criteria for opioid dependence and at least 18 years of age.	n = 360	UDT confirmed self-report of opioid abstinence-success defined as abstinence from opioids during the final study week (week 12) as well as < = 2 of the 3 proceeding weeks Treatment attendance (attended > = 60 % of assigned sessions
Technological Interventions
15	Ruetsch et al. (2012)	RCT	US n/a	Age 31.8 (11.3) 41 % women 88 % white. Patients were eligible for inclusion if they were new to buprenorphine or had not received buprenorphine for at least 6 months, no signs of organic brain disorder and not pregnant.	n = 1426	Self-reported opioid use ASI score Self-reported attendance in self-help group Buprenorphine compliance
16	Shi et al. (2019)	RCT	US Primary care center	Age: 40.5 (12.2) 40 % women 100 % white, 5% Latino Individuals 18 years + and met DSM-5 criteria for opioid use disorder. Polysubstance users included (marijuana, tobacco).	n = 21	Percentage of UDTs negative for all drugs.
17	Schuman-Olivier et al. (2018)	Single arm, open label clinical trial	Boston, MA Metropolitan area, USA n/a	Age: 31.3 (2.84) 33 % women 92 % white Adults age 18–39 with clinical diagnosis of opioid use disorder (DSM-5) classified as “unstable” in office-based buprenorphine treatment, at risk of return to use and termination of treatment. Polysubstance users included.	n = 12	Feasibility Usability Acceptability
Complementary Interventions
18	Price et al. (2020)	RCT	Washington, US Primary care clinic & Specialty addiction clinic within a large community medical center	Age: 46.6 (12) 30 % women 60 % white, 20 % multiracial, 10 % native Hawaiian or Pacific Islander, 10 % Native American or Alaskan Native. Individuals prescribed buprenorphine for OUD who had been enrolled in treatment for a minimum of four weeks.	n = 10	Intervention acceptability Intervention satisfaction Intervention skills learned
19	Lander et al. (2018)	Prospective pilot study using quasi-experimental design with matched controls.	West Virginia, US Outpatient buprenorphine clinic	No age data No gender data 96 % white. Adults over 18 with a diagnosis of opioid use disorder (DSM-5 Criteria) within the last 12 months and active buprenorphine treatment for more than 90 days.	n = 26	Number of days abstinent from all substances including alcohol (UDT and self-report) Retention on buprenorphine (UDT and self-report) Rate of return to use (self-report of 1 or more return to use on any substance)
Structural Barriers to Care
20	Cochran et al. (2018)	Single group repeated measures study	Pennsylvania, US Outpatient, office-based buprenorphine clinic serving pregnant women	Age: 29.7 (5.7) 100 % women 95 % White Treatment seeking pregnant women ≥18+, DSM diagnosis of opioid dependence verified by medical record review and urine toxicology.	n = 21	Illicit opioid, other drug use (self-report) Health and mental health (self-report) Treatment engagement (self-report)

Average age and standard deviation (SD) are reported.