Table 3 Metrics for acceptability and feasibility outcomes

 Session-level engagement

° < 4 on a 9-point Likert scale, with 8 (0–8 range) representing the highest possible engagement.

° Score of 4 or 5 on a 9-point Likert scale.

° ≥ 6 on a 9-point Likert scale.

 Treatment credibility and expectancy

° < 5 on an 11-point Likert scale, with 10 (0–10 range) representing the highest level of credibility.

° Score of 5 to 7 on an 11-point Likert scale.

° ≥ 8 on an 11-point Likert scale.

 Satisfaction with intervention content

° < 2 on a 5-point Likert scale, with 4 (0–4 range) representing the highest degree of satisfaction with session content.

° Score of 2 on a 5-point Likert scale.

° ≥ 3 on a 5-point Likert scale.

 Global treatment satisfaction

° < 2 on a 4-point Likert scale, with 4 (1–4 range) representing the highest level of global treatment satisfaction.

° Score of 2 on a 4-point Likert scale.

° ≥ 3 on a 4-point Likert scale.

 Enrollment rates

° < 70% of participants who enroll commence treatment.

° 70–90% of participants who enroll commence treatment.

° > 90% of participants who enroll commence treatment.

 Participant retention

° < 70% participant retention by the 7-week time point.

° 70–80% participant retention by the 7-week time point.

° > 80% participant retention by the 7-week time point.

 Questionnaire feasibility

° < 80% completion of study questionnaires (treatment outcomes and mediators).

° 80–90% completion of study questionnaires.

° > 90% completion of study questionnaires.

 Home activity feasibility

° < 3 on a 7-point Likert scale, with 6 (0–6 range) representing the highest level of feasibility associated with home activity completion.

° Score of 3 or 4 on a 7-point Likert scale.

° ≥ 5 on a 7-point Likert scale.