My Avenue to helP - Adaptive Mentalization-based Integrative Treatment Compared to Management as Usual for Youths With Multiple Problems: a Non-Randomized Controlled Feasibility Trial

Feasibility outcome 1 will be assessed by calculating the proportion of families that accept inclusion out of those who fulfill inclusion criteria. The intervention will be deemed acceptable if ≥50% of the families that are eligible (assessed at an informational meeting) also consent to participate in the MAP study.

Feasibility outcome 2 will be assessed by contacting the Keyworker monthly to inquire about the contacts made/attempted by the Keyworker to the young person/network around the young person. Type of contact made between the Keyworker and the young person, and alternatively whom the Keyworker was in contact with within the indigenous network of the young person, in cases where the young person does not want direct contact with the Keyworker, will be registered as well. The intervention will be deemed acceptable if ≥70% of youths in the MAP intervention do not experience a pause of 4 continuous weeks between contacts.

Feasibility outcome 3 regarding the satisfaction with treatment in MAP will be assessed using item 16.4 of the Client Satisfaction Questionnaire. The intervention will be deemed acceptable if ≥70% of youths and parents would recommend MAP to a friend.

Feasibility outcome 4 will be assessed by a questionnaire developed for the MAP project and will be delivered to all workers (in the MAP teams) and leaders involved in MAP in Roskilde, Lejre, and CAMHS. The intervention will be deemed acceptable if >70% of MAP team staff and leaders will continue to prioritize the intervention.

Feasibility outcome 5 will be deemed acceptable if ≥70% of youths who consented to participate in the MAP project, participated in the 'Personal and Social Performance Scale Interviews at baseline and after 1 year.

Change in youths' social function covering four domains (socially useful activities, personal and social relationships, self-care, disturbing and aggressive behaviors, measured with the Personal and Social Performance (PSP) Scale, rated by researchers using multiple sources of information. Overall functioning will be scored on a scale from 0 (minimum value [worst outcome], complete lack of autonomy) to 100 (maximum value [best outcome], excellent functioning).

We anticipate no or minimal adverse effects or adverse events related to the AMBIT and MAU interventions in the trial. The independent observer will be responsible for the recording and classification of events based on the weekly contact with the participants and surveillance of the electronic health record system (Sundhedsplatformen) to cover adverse events according to the following definitions:

Adverse Event (AE): any undesirable medical event occurring to a participant during a clinical trial, which does not necessarily have a causal relationship with the intervention.

Adverse Reaction (AR): any undesirable and unintended medical response related to the intervention occurring to a participant during a clinical trial.

Serious Adverse Event (SAE): any adverse event that results in death, is life-threatening, requires hospitalization or prolongation of existing hospital stay

Participation in education, employment, or training in the past four weeks, rated by an independent observer based on multiple sources of information from a short interview in connection with the Personal and Social Performance Scale assessment.

Change in well-being, self-reported with the WHO-5 well-being index. The WHO-5 includes 5 questions scored on a Likert scale from 0 (low well-being) to 5 (high well-being) resulting in a sum score of 0 to 25.

Change in personal recovery, self-reported, measured by the Brief INSPIRE-O, which has recently been validated in a Danish context. The Brief INSPIRE-O includes 5 questions scored on a Likert scale from 0 (low well-being) to 4 (high well-being) resulting in a sum score of 0 to 20.

Change in health-related quality of life measured by the Child Health Utility 9D (CHU9D), self- and parent-reported. All nine items of the CHU9D have five unnumbered response options which are converted to scores of 1-5, resulting in a sum score of 9 to 45. The instrument allows for the calculation of Quality-Adjusted Life Years (QALYs). It is a measure used to assess how many good life years are gained or lost by introducing new health technology or organization.

Mental health problems and disorders measured by the Strengths and Difficulties Questionnaire (SDQ) (Goodman, 1999), self- and parent-reported. The SDQ contains 25 items, which cover five subscales relating to the children's emotional problems, peer problems, behavioral problems, hyperactivity and pro-social behavior. Responses to the subscales on emotional problems, peer problems, behavioral problems, and hyperactivity can be used to calculate a total difficulties score. Each subscale score ranges from 0-10, implying that the total difficulties score ranges from 0 to 40 An impact score is calculated from five items; whether the difficulties upset or distress the child and how much the difficulties interfere with home life, friendships, classroom learning, and leisure activities. Each item is scored on a scale from 0 to 10. To score 1 or 2, the interference from the difficulties in that domain must be assessed to either "quite a lot" or "a great deal", resulting in an impact score.

Participant satisfaction measured with the Client Satisfaction Questionnaire, self-reported. The scale consists of 8 questions scored on a 4-point Likert Scale ranging from low to high satisfaction with different aspects of the intervention. The total score ranges from 8 (minimum value [bad outcome], low satisfaction) to 32 (maximum value [good outcome], high satisfaction).

Parental satisfaction and experience with the treatment of their child will be measured with the Experience of Service Questionnaire. The scale consists of 10 questions scored on a 3-point Likert Scale. The total score ranges from 0 (minimum value [bad outcome], poor satisfaction]) to 20 (maximum value [good outcome], high satisfaction]).

Adherence to planned care in CAMHS and the use of emergency healthcare will be assessed through information from the young person's patient records.