Heiderscheit 2005.

Study characteristics
Methods	Study design: RCT Study grouping: parallel group Randomisation method: coin flip Allocation concealment: unclear, insufficient information
Participants	Baseline characteristics MT + SC Gender male: 8 (80%) Mean age: 49 (SD 7.3) years Sample size: 10 Drug of choice – alcohol: 9 (90%) Drug of choice – cocaine: 1 (10%) Co‐occurring mental health diagnosis: 8 (80%) SC Gender male: 7 (77.7%) Mean age: 57.8 (SD 7.1) years Sample size: 9 Drug of choice – alcohol: 8 (88.8%) Drug of choice – cocaine: 1 (11.1%) Co‐occurring mental health diagnosis: 8 (88.8%) Overall Gender male: 15 (78.9%) Mean age: 55.9 (SD 7.2) years Sample size: 19 Drug of choice – alcohol: 17 (89.5%) Drug of choice – cocaine: 2 (10.5%) Co‐occurring mental health diagnosis: 16 (84.2%) Inclusion criteria: admitted to the inpatient chemical dependency programme at a skilled nursing facility Exclusion criteria: non‐English speaking; diagnosis of dementia, psychosis, or psychotic state Pretreatment: the difference in number of previous treatment episodes between the experimental and control groups was not statistically significant. The difference between groups on the length of current treatment was not statistically significant. Confirmation of population eligibility (from study author): author confirmed via email on 14 September 17: "All the clients enrolled in the study carried a primary diagnosis of substance dependence/abuse per the DSM‐IV, as it was an addictions treatment program".
Interventions	Intervention characteristics MT + SC Description: GIM sessions, conducted by researcher (who was trained in BMGIM), including 20–30 minutes for verbally processing the imagery experience Session length: mean 1.75 hours Frequency: once/week Duration of treatment: 4–7 weeks, mean 5.8 (SD 1) SC Description: SC was comprised of verbal group therapy, spirituality, 12 step group based on the 12 steps of Alcoholics Anonymous, recreational group sessions which included staff supervised outings and family group sessions Session length: no information Frequency: no information Duration of treatment: no information
Outcomes	Retention in treatment Outcome type: dichotomous outcome Direction: higher is better Data value: endpoint Notes: retention in treatment calculated as the % of participants remaining in treatment at the conclusion of the treatment Not used: Interpersonal problems (IIP‐SC), sense of coherence (Sense of Coherence Scale), immunofunction (salivary immunoglobulin A)
Identification	Sponsorship source: none Country: USA Setting: adult inpatient substance abuse treatment programme Author's name: Annette Lynne Heiderscheit Institution: Augsburg College Email: heidersc@augsburg.edu Declarations of interest: no conflicts of interest reported
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Judgement comment: random assignment by use of coin toss.
Allocation concealment (selection bias)	Unclear risk	Judgement comment: used a coin flip, which does not assure adequate concealment of allocation.
Blinding of participants and personnel (performance bias) Objective outcomes	Low risk	Judgement comment: not possible to blind participants and providers to MT intervention.
Blinding of outcome assessment (detection bias) Objective outcomes	Low risk	Judgement comment: outcome assessor blinded for retention in treatment.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: no missing outcome data.
Selective reporting (reporting bias)	Low risk	Judgement comment: no selective outcome reporting.
Blinding of participants and providers (performance bias) (subjective outcomes)	Low risk	Judgement comment: not possible to blind participants and providers to MT intervention.
Blinding of outcome assessor (detection bias) (subjective outcomes)	Unclear risk	Judgement comment: not possible to blind outcome assessor for self‐report outcomes, though measurement not likely to be influenced differentially between groups.