This mixed-methods acceptability study aims to investigate whether an early acceptance and commitment therapy (ACT) based intervention called ProACTive, aimed at supporting burns patients' adjustment to a changed appearance and preventing distress, is acceptable. This will be measured by descriptive data, questionnaire data and semi-structured interviews.

Preliminary data on the potential clinical effectiveness of the intervention will also be gathered. This will be measured by scores on standardised questionnaires.

Evidence suggests that appearance concerns after burn injuries start early. Appearance concerns can be chronic, create psychological distress and impact quality of life. No early psychological interventions for appearance concerns after burn injuries currently exist.

ProACTive, a novel psychological intervention (talking therapy), utilising acceptance and commitment therapy (ACT) techniques with an additional focus on developing self-compassion and social skills training, was developed. It aims to help burns patients adjust to changes to appearance and prevent distress. It involves up to five 30-minute modules and patients can select how many, and which, modules to complete. It is delivered by a psychological professional working in burns services.

The primary aim of this study is to explore whether the ProACTive intervention is acceptable to burns patients. A secondary objective is to gather preliminary data on the potential clinical effectiveness of the ProACTive intervention.

A mixed-methods single-arm acceptability study will be conducted.

ProACTive will be offered to burns patients (aged 18 years or over) meeting inclusion criteria and admitted to the burns service at Nottingham University Hospitals NHS Trust.

Fifteen participants will be recruited to complete the intervention.

The primary objective of exploring the acceptability of the ProACTive intervention will be measured by:

• Intervention update rate (percentage of those invited to participate in the study)
• Descriptive data about reasons for not taking up the intervention (if patients consent to participating in the study in this way)
• Patient feedback gathered through a semi-structured exit interview as soon as possible after the intervention ends (within two weeks)
• Patient feedback gathered using a standardised self-report questionnaire to record helpful and hindering aspects of the intervention will be completed after every session completed.
• Descriptive data about how many, and which of, the sessions patients choose to complete and the spacing of sessions completed
• The number of sessions completed during hospital admission and after hospital discharge, and whether these were completed face to face or virtually
• Descriptive data about participants' preferences for receiving the post-session resources in paper or electronic format
• The number of times participants viewed the post-session online videos containing audio-exercises
• Descriptive data about reason for ending the intervention before all sessions have been completed

Template analysis (King, 2012), a form of thematic analysis (Braun & Clarke, 2006), will be used to analyse patterns of meaning, or themes, within the transcripts of the interviews. The Theoretical Framework of Acceptability (TFA; Sekhon et al., 2017) will also be used to develop the interview schedule and the initial coding template.

The secondary objective to gather preliminary data on the potential clinical effectiveness of the ProACTive intervention will be examined through scores on four standardised self-report measures of:

• Appearance concerns
• Positive and negative affect
• Psychological flexibility
• Self-compassion

These measures will be completed before and after the intervention. Wilcoxon tests will be used to compare pre- and post-intervention scores. These exploratory analyses will indicate the extent to which appearance concerns decrease, and psychological flexibility and self-compassion increase post-intervention compared to pre-intervention. Differences between pre- and post-intervention means will also give an indication of the likely effect size of the intervention (Cohen's d).

The outcome of the study will include knowledge about whether ProACTive is acceptable to burns patients when it is introduced during hospital admission and preliminary evidence about the effectiveness of ProACTive. These outcomes will contribute to further intervention refinement and trial development.

Inclusion Criteria:

• Adult patients (18 years and over) admitted as inpatients to the burns service with an acute burn injury

Exclusion Criteria:

• Patients already receiving psychological input from the burns clinical psychology service for appearance related concerns, over and above supportive listening
• Patients admitted as inpatients to the burns service for reconstructive surgery, for a historical burn injury
• Patients who are too physically unwell to participate
• Patients deemed too psychologically unwell or in a mental health crisis by the usual clinical care team (for example, patients who sustained their burn injury due to a suicide attempt or self-harm, are currently having suicidal thoughts, or those with psychosis)
• Patients who are not fluent in the English language in order to participate
• Patients with a known cognitive impairment

Open Science Framework. Final template of themes (qualitative data).

Acceptance of manuscript for publication.

The data will be made publicly available on the Open Science Framework upon acceptance of the manuscript for publication.