The acceptability of a guided internet-based trauma-focused self-help programme (Spring) for post-traumatic stress disorder (PTSD).

: Guided internet-based, cognitive behavioural therapy with a trauma-focus (i-CBT-TF) is recommended in guidelines for post-traumatic stress disorder (PTSD). There is limited evidence regarding its acceptability, with significant dropout from individual face-to-face CBT-TF, suggesting non-acceptability at least in some cases.: To determine the acceptability of a guided internet-based CBT-TF intervention, 'Spring', in comparison with face-to-face CBT-TF for mild to moderate PTSD.: Treatment adherence, satisfaction, and therapeutic alliance were measured quantitatively for participants receiving 'Spring' or face-to-face CBT-TF as part of a Randomised Controlled Trial. Qualitative interviews were conducted with a purposive sample of therapists and participants.: 'Spring' guided internet-based CBT-TF was found to be acceptable, with over 89% participants fully or partially completing the programme. Therapy adherence and alliance for 'Spring' and face-to-face CBT-TF did not differ significantly, apart from post-treatment participant-reported alliance, which was in favour of face-to-face CBT-TF. Treatment satisfaction was high for both treatments, in favour of face-to-face CBT-TF. Interviews with participants receiving, and therapists delivering 'Spring' corroborated its acceptability.: Guided internet-based CBT-TF is acceptable for many people with mild to moderate PTSD. Findings provide insights into future implementation, highlighting the importance of personalising guided self-help, depending on an individual's presentation, and preferences.