Table 1 Steps and tasks undertaken in the intervention development

Step 1: Needs assessment

1. Established a working group of parent carers in the PenCRU Family Faculty who were involved in the subsequent steps and tasks.

2. Conducted needs assessment through (i) consultations with parent carers, (ii) consultations with stakeholders, and (iii) literature search and review.

Step 2: Developing programme outcomes and change objectives

1. Specified and agreed on programme outcomes.

2. Specified and selected modifiable determinants of outcomes.

3. Determined change and performance objectives for programme outcomes (i.e. what needs to change and what steps need to be taken in order to meet programme outcomes), and created a matrix of change and performance objectives.

Step 3: Selecting methods and practical applications

1. Generated ideas for programme content and delivery with parent carers working group.

2. Identified and selected theory-based programme methods (i.e. behaviour change techniques) and practical applications to deliver intervention content and behaviour change techniques.

3. Specified intervention logic model.

Step 4: Designing programme components

1. Specified programme scope and themes, and designed programme materials, including the Facilitator Manual and the Guide for Parent Carers.

2. Reviewed programme materials with parent carers working group and pre-tested some of the activities includes in the programme.

3. Produced programme materials (i.e. Facilitator Manual, materials to be used in the group activities, Guide for Parent Carers), feedback and outcome assessment forms, and prepared tools to be used in the sessions.

Step 5: Testing intervention feasibility and acceptability and incorporating feedback

1. Planned a feasibility study to test feasibility of intervention delivery and acceptability of the intervention content and delivery; developed a study protocol; received ethics approval.

2. Recruited participants.

3. Delivered the group sessions; collected feedback from participants and facilitators.

4. Identified and incorporated the feedback and suggestions to improve the intervention design and delivery, as well as identified potential solutions to issues related to feasibility and implementation.

Step 6: Planning intervention adoption, implementation and future evaluation

1. Identifying potential stakeholders to involve in adoption and implementation of the intervention.

2. Reviewing and revising programme content, delivery methods and materials.

3. Specifying design of a pilot/evaluation study; developing an outcome and process evaluation plan.

4. Developing study protocol; piloting and evaluating the programme.