Table 1.

Outcome measures

Study instrument	Description
Health of the Nation Outcome Scale for Children and Adolescents75	Used to assess the need for care based on a wide range of problems (behaviour, impairment, symptoms and social functioning)
Transition Related Outcome Measure*	Informs on quality of transition and changes in symptoms, risk factors and impairment due to transition; it has been developed based on the TRAM
WHO Quality of Life Brief Inventory76 77	Assesses quality of life, covering physical and psychological health, social relationships and current environment
MILESTONE-specific Client Service Receipt Inventory62	Focuses on the use of health and social services, and medication use
EuroQol health questionnaire (EQ-5D-5L)63	Assesses health-related quality of life states consisting of five dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression)
ASEBA: Youth Self Report/Adult Self Report/Child Behavior Checklist/Adult Behavior Checklist78 79	Suite of measures assessing dimensions of emotional and behavioural problems
Ethics of Transitioning*	Assesses ethical challenges regarding the delivery of transitional care
Independent Behaviour During Consultation Scale80	Measures independent behaviour
Barriers to Care81	Assesses practical (eg, costs, time) and psychological barriers (eg, fear to stigmatisation) to care
Bullying—adapted from Retrospective Bullying and Friendship Interview Schedule82 83	Assesses the experiences with bullying in different settings (eg, school, at home, college)
Life Events*	Assesses significant life events such as accidents, deaths in the family, separation of parents/carers and parent/carer losing jobs
Brief Illness Perception Questionnaire84 85	Assesses the cognitive and emotional representation of illness, including consequences; the term ‘illness’ has been replaced with the term ‘condition’
On Your Own Feet: Transition Experience Scale86	Focuses on specific experiences with the transition process and has two versions: one for young people who transition to AMHS (or other types of adult care) and one for young people discharged from CAMHS
Specific Levels of Functioning Scale87	Assesses adult functioning of the young person from the parent/carer’s perspective
Clinical Global Impression Severity scale88	Assesses the severity of the patient’s illness at the time of assessment, relative to the clinician’s past experiences

*Developed specifically for the MILESTONE study.

AMHS, adult mental health services; CAMHS, child and adolescent mental health services; MILESTONE, Managing the Link and Strengthening Transition from Child to Adult Mental Healthcare; TRAM, Transition Readiness and Appropriateness Measure.