Table 1 Feasibility progression criteria with traffic light indicators

Recruitment

Ability to randomise 66 participants in an 11-month recruitment window

 ≥ 80%

60–79%

 < 60%

Adherence

Percentage of participants receiving the minimum dose of therapy (≥ 2 sessions) within 8-week treatment window^a

 ≥ 80%

60–79%

 < 60%

Retention

Percentage of participants completing the 24-week assessment as potential primary outcome timepoint

 ≥ 80%

60–79%

 < 60%

Outcome suitability

Informed by qualitative workstream plus percentage of participants completing the Beck Scale for Suicidal Ideation at all timepoints

 ≥ 80%

60–79%

 < 60%

Safety

Monitoring and review of research-related serious adverse events (SAEs). The Trial Steering Committee (TSC) will oversee SAEs across treatment arms. We will consider discontinuation of the trial if the intervention or procedures are deemed to elevate risk