Hazell 2009.

Study characteristics
Methods	Allocation: random allocation conducted by a distant site coordinator. Follow‐up period: 12 months N lost to follow up: 0/72 for repetition data.
Participants	Inclusion criteria: i) aged between 12 and 16 years; ii) referred to a child and adolescent mental health service in Newcastle, Brisbane North, or Logan; iii) reported at least two episodes of self‐harm in the past year, one of which occurred within the past 3 months. Exclusion criteria: i) required intensive treatment owing to an imminent risk of SH; ii) diagnosed with acute psychosis; iii) diagnosed with an intellectual disability or other disorder that would indicate the patient was unlikely to benefit from group therapy sessions; iv) current level of SH risk precluded participation in group therapy sessions. Numbers: Of the 72 participants, 35 were allocated to the experimental arm and 37 to the control arm. Profile: 90.3% (n = 65) were female, 100% (n = 72) were multiple repeaters, 4.1% (n = 3) had alcohol problems, 0% (n = 0) had substance misuse problems, 56.9% (n = 41) were diagnosed with depression; 6.9% (n = 5) had a diagnosis of conduct/oppositional defiant disorder. Source of participants: patients referred to a child and adolescent mental health service who had reported at least two episodes of SH in the past year, one within the past 3 months. Setting: Newcastle, Brisbane North, and Logan, New South Wales and Queensland, Australia.
Interventions	Experimental: group therapy involving CBT, social skills training, interpersonal psychotherapy, group psychotherapy in addition to treatment as usual. Control: treatment as usual involving individual counselling, family sessions, medication assessment and review, and other care co‐ordination. Therapists: clinicians in community‐based adolescent mental health services. Type of therapy offered: group psychotherapy. Length of treatment: 12 months.
Outcomes	Included: i) repetition of SH according to self‐report; ii) suicide; iii) suicidal ideation; iv) depression. Excluded: None
Notes	Source of funding: no specific sources of funding were reported for this study. Declaration of author interests: "Prof. Hazell has received research funding from Celltach and Eli Lilly; has served as a consultant to Eli Lilly, Janssen‐Cilag, Novartis, and Shire; and has participated in the speakers' bureaus of Eli Lilly, Janssen‐Cilag, and Pfizer. The other authors report no conflicts of interest" (p.669).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Comment: Correspondence with study authors revealed that a computer generated random number table was used to generate the random sequence. Randomisation by location and by blocks of four were also used to ensure a similar number of adolescents were recruited from each study location.
Allocation concealment (selection bias)	Low risk	Quote: "The local site co‐ordinator emailed the distant site co‐ordinator, who assigned a trial number and randomly allocated that adolescent to group therapy or routine care" (p.664) Comment: Use of a remote site co‐ordinator is likely to have ensured allocation was adequately concealed.
Blinding (performance bias and detection bias) Of participants	High risk	Quote: "The adolescent was informed of his or her allocation by a letter and by their routine care therapist" (p.664).
Blinding (performance bias and detection bias) Of personnel	High risk	Quote: "The adolescent was informed of his or her allocation by a letter and by their routine care therapist" (p.664) Comment: Given that the therapist is informing participants as to their allocation, this would suggest personnel were also not blinded to allocation.
Blinding (performance bias and detection bias) Of outcome assessors	Low risk	Quote: "Treatment allocation was concealed from the outcome assessors, who were asked at the end of the study to nominate which treatment had been given to the adolescents" (p.664)
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Quote: "Continuous outcome data were analyzed on an intent‐to‐treat basis" (p.664) Comment: Intention‐to‐treat analyses made using the last outcome carried forward method.
Selective reporting (reporting bias)	Unclear risk	Comment: No reason to suspect that all outcomes were not measured, however, in the absence of the trial protocol, this cannot be ascertained.
Other bias	Low risk	Comment: No apparent other sources of bias.