Table 1.
Questionnaire assessments
| What is assessed | Completed by | Timepoint | |
|---|---|---|---|
| Beck Scale for Suicide Ideation | Suicidal ideation: intent and the severity of actual suicidal wishes and plans | Young person | Baseline, 12, and 18 months |
| Paediatric Quality of Life Enjoyment and Satisfaction questionnaire | Quality of life of young person: general | Young person | Baseline, 12, and 18 months |
| General Health Questionnaire-12 | Quality of life of caregiver: mental health | Caregiver | Baseline, 12, and 18 months |
| Children's Depression Rating Scale—revised | Depression: severity of depressive syndrome | Young person | Baseline, 12, and 18 months |
| Strengths and Difficulties Questionnaire | Overall mental health and emotional and behavioural problems | Young person and caregiver | Baseline, 12, and 18 months |
| Hopelessness Scale for Children | Hopelessness: degree to which young people have negative expectancies of themselves and the future | Young person | Baseline, 12, and 18 months |
| McMaster Family Assessment Device | Family functioning | Young person and caregiver | Baseline, 12, and 18 months |
| Family Questionnaire | Family functioning: different ways in which families try to cope with everyday problems and expressed emotion | Young person and caregiver | Baseline, 3, and 6 months |
| Suicide Attempt Self-Injury Interview | Self-reported self-harm: factors involved in non-fatal suicide attempts and intentional self-injury, providing a timeline of self-harm episodes | Young person | Baseline, 12, and 18 months |
| Inventory of Callous Unemotional Traits | Callous, uncaring, and unemotional traits of young person | Young person and caregiver | Baseline |
| EQ-5D-3L | Health economics: health problems across dimensions, converted into health utilities | Young person | Baseline, 6, 12, and 18 months |
| Health Utilities Index 3 | Health economics: quality of life health status classification system, converted into health utilities | Caregiver | Baseline, 6, 12, and 18 months |
| Health economics questionnaire | Trial-specific questionnaire for health economics | Young person and caregiver | Baseline, 3, 6, 12, and 18 months |
| System for Observing Family Therapy Alliances | Engagement with therapy | Young person, caregiver, and therapist | 3 months |
When it was not possible to arrange face-to-face follow-up interviews, and participants agreed, self-report questionnaires were posted to participants to complete. Postal questionnaires were sent at 3 and 6 months after random group assignment, preceded by a phone call from researchers.