Cotgrove 1995.

Study characteristics
Methods	Allocation: random allocation using open number table. Follow‐up period: 12 months. N lost to follow up: 0/105 (0%) for repetition of SH data.
Participants	Inclusion criteria: i) aged 16 years or under. Exclusion criteria: i) records of original suicide attempt missing or those with "insufficient follow‐up data" (p.572). Numbers: Of the 105 participants, 47 were allocated to the experimental arm and 58 to the control arm. Profile: 85% (n = 89) were female, 6% (n = 6) were diagnosed with a major psychiatric disturbance (not specified). Source of participants: patients admitted to hospital following SH. Location: North London, UK.
Interventions	Experimental: emergency green card in addition to usual care. The green card acted as a passport to re‐admission into a paediatric ward at the local hospital. Control: standard follow‐up including treatment from a clinic or child psychiatry department as required. Therapist: no details provided. Type of therapy offered: emergency green card. Length of treatment: 12 months.
Outcomes	Included: i) repetition of SH according to clinical and hospital notes. Excluded: i) use of emergency card.
Notes	Source of funding: no details on funding were provided. Declaration of author interests: no details on author interests were provided.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: “Adolescents were allocated randomly” (p.570). Following correspondence with the study authors, it became apparent that a random open numbers table had been used to generate the sequence. Comment: As the numbers table was open, it is possible there may have been bias in the generation of the random sequence.
Allocation concealment (selection bias)	High risk	Comment: As the numbers table was open, it is unlikely allocation could have been adequately concealed.
Blinding (performance bias and detection bias) Of participants	High risk	Quote: “Those in the treatment group received a token, a green card, which acted as a passport to re‐admission into a paediatric ward in their local hospital” (p.570) Comment: The nature of this study means that participants could have known to which group they had been allocated.
Blinding (performance bias and detection bias) Of personnel	Unclear risk	Comment: No details on blinding of clinical personnel provided.
Blinding (performance bias and detection bias) Of outcome assessors	Unclear risk	Comment: No details on blinding of outcome assessors provided.
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: Of the eligible 134 consecutive admissions only "105 were included in the follow‐up study..." Comment: Unclear as to why these participants were excluded.
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	High risk	Quote: "Forty seven adolescents (45%) were randomly allocated to the treatment group and 58 (55%) to the control.... The reasons there were larger numbers in the control group was partly due to chance, and partly due to an error in one centre in the way five of the green cards were issued; either several weeks after discharge without adequate explanation, or in a couple of cases, not at all. This invalidated the follow‐up data from this centre for these five cases in the treatment group, but not on those in the control group." (p. 572) Comment: The inclusion of participants who may have received the treatment intervention within the control group may lead to bias in the estimation of the treatment effect, particularly as it is unclear how these five cases were assessed. Additionally, the authors claim the intervention was effective even though comparison of repetition rates was not significantly different between groups.