Table 1 Development of the delivery model of the intervention

Format: Online vs. offline

Overall consensus was an option for a mix of mediums, with face-to-face delivery being prioritized.

Most trials undertaken face-to-face with online mode of delivery used in one more recent study.

Face-to-face prioritized so that in-depth work can be done & YP body language read. Online sessions could be held if client felt more comfortable. Short online videos used as a learning resource.

Format: individual vs. group sessions

Individualised approach recommended as group session could be intimidating for a sensitive topic.

Potential for group work to play a vital role in opening important discussions and providing an opportunity for social connection.

Most trials have tested group-based interventions. Groups used particularly with populations that were together already (e.g. justice involved youth, home based care).

Individual sessions to explore the core concepts within the intervention to build confidence.

An optional group session ran monthly to discuss sexual health with peers in a safe space.

Format: number & duration of sessions

Between 1 and 8 sessions suggested. Minimising commitment from YP viewed as best.

Length of session suggestions varied30-90 min.

Intervention length and duration very varied, ranging from 45 min to 8 h, delivered over one to 24 sessions.

One initial consultation session followed by four individualised sessions lasting 60–90 min selected as most consistent feedback.

One optional 90-minute group session monthly proposed to be trialed.

Format: frequency

Fortnightly sessions were chosen by stakeholders over weekly to allow time for content to be absorbed.

Intervention frequency very varied, delivered over one day to 7 months.

Sessions delivered fortnightly to allow for time to avoid YP feeling overwhelmed.

Delivery: location

Private space, familiarity and easily accessible for YP. Classrooms in schools also suggested.

All but two trials took place in locations that the young people were already engaged in (e.g., mental health clinic, group home, drop-in centres), rather than at schools.

Classroom sessions were not feasible for this intervention due to ethics. Private interview rooms in spaces that the YP may visit for mental health services were chosen.

Zoom chosen as ‘online’ location for telehealth appointments due to platform familiarity.

Delivery: person to deliver

A multidisciplinary approach of sexual health clinicians, mental health clinicians and youth peer workers were consistently suggested.

Lived-experience frequently mentioned as beneficial quality.

Person who delivered intervention varied greatly by at-risk population and research group. Resources available within the context of the research project typically contributed to decisions.

Practical constraints contributed to current decision to use a young ‘sex-positive’ clinician already involved in the project (HN) who undertook further sexual health training.

Youth peer workers with lived experience would be engaged to co-host the monthly group sessions.