Donaldson 2005.

Study characteristics
Methods	Allocation: Following correspondence with study authors, it became apparent that simple randomisation using a random numbers table had been used to generate the allocation sequence. Follow‐up period: 3 and 6 months. Follow‐up data on functioning for a sub‐sample of participants was available for 12 months. N lost to follow up: 8/39 (21%) for repetition data.
Participants	Inclusion criteria: i) aged 12‐17 years; ii) primary language was English; iii) outpatient care indicated; iv) intent to die indicated. Exclusion criteria: i) psychosis indicated on mental status examination; ii) clinician judgement that intellectual functioning precluded outpatient psychotherapy. Numbers: Of the 39 participants, 21 were allocated to the experimental arm and 18 to the control arm. Profile: 48% (15/31) were repeaters, 29% (9/31) were diagnosed with major depression, 19% (6/31) were diagnosed with alcohol use disorder. Source of participants: patients presenting to a general paediatric emergency department or inpatient unit of an affiliated child psychiatric hospital after a suicide attempt. Location: Northeast USA, possibly Providence, RI.
Interventions	Experimental: Skills‐based treatment focused on improving problem solving and affect management skills. Additionally, participants were taught problem solving and cognitive and behavioural strategies and given homework assignments to further improve their skills. Treatment comprised two parts: i) active treatment for the first three months which included six individual sessions and one adjunct family session with two additional family sessions and two crisis sessions available at the therapist’s discretion; ii) maintenance treatment for the remaining three months which included three sessions. Control: Supportive relationship therapy focused on addressing the adolescent's mood and behaviour, including unstructured sessions which addressed reported symptoms and problems, and fostered the development of specific skills not otherwise addressed during treatment. This intervention was designed to resemble usual care for this population in this community. Therapist: 5 clinicians and 2 individuals with master’s degrees provided treatment for both study arms. Type of therapy offered: problem solving therapy. Length of treatment: 6 months.
Outcomes	Included: i) repetition of SH; ii) suicide; iii) suicidal ideation; iv) depression; v) problem solving; vi) compliance. Excluded: i) anger.
Notes	Source of funding: "This project was supported by NIMH (MH05749), the American Foundation for Suicide Prevention, and the Harvard Pilgrim Research Foundation" (p.113). Declaration of author interests: No details on author interests were provided. Other: Data on repetition of SH were obtained from reports from adolescents and parents. Data on suicides were obtained following correspondence with study authors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “[Participants were r]andomized to one of two treatment conditions” (p.114) Comment: Correspondence with study authors confirmed that a random numbers table was used to generate the allocation sequence. Use of a random numbers table is likely to have minimised the role of bias in the generation of the randomisation sequence.
Allocation concealment (selection bias)	Unclear risk	Comment: No information on allocation concealment was provided.
Blinding (performance bias and detection bias) Of participants	Unclear risk	Comment: No information on participant blinding was provided. However, both treatments were so similar that it is possible participants were unaware of which treatment they were receiving.
Blinding (performance bias and detection bias) Of personnel	High risk	Quote: “The same seven therapists provided treatment in both...conditions” (p.114) Comment: Therapists are likely to have known which participant was receiving which treatment.
Blinding (performance bias and detection bias) Of outcome assessors	Unclear risk	Quote: “Outcome measures were administered...by a trained bachelor’s degree level research assistant” (p.115) Comment: No information on outcome assessor blinding was provided.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: “Follow‐up data from all 31 families who completed follow‐ups (regardless of number of treatment sessions attended) were included in data analyses consistent with an intent to‐treat model” (p.115) Comment: In addition to performing analyses in line with the intention‐to‐treat principle, the authors also compared study participants at baseline to those who dropped out of treatment and concluded there were “no significant differences” in the results obtained. Of the 39 randomised participants, 31 completed the 3 or 6 month evaluations.
Selective reporting (reporting bias)	Unclear risk	Comment: Suicide data were obtained through correspondence with the study authors, suggesting that selective reporting bias may have been present.
Other bias	High risk	Comment: Contamination is possible given that the same seven therapists delivered both the experimental and control treatments.