International Adaptation of a brief Problem-Solving Skills (the IAPPS trial) training for people in custody with severe mental illness in Poland: an open multicentred, parallel group, feasibility randomised controlled trial.

Objectives: The primary aim of this study was to assess the feasibility of delivering an adapted problem-solving skills (PSS) intervention by quantifying the recruitment, follow-up and completion rates using a brief problem-solving intervention for people with a mental health diagnosis in two Polish prisons. Design: IAPPS is an open, multi-centred, parallel group feasibility randomised controlled trial (RCT). Setting: Two prisons in Poland. Participants: Men in custody aged 18 years and older, having a mental illness and living within the prison therapeutic unit. Interventions: The intervention consisted of an adapted PSS skills intervention plus care as usual (CAU) or care as usual only. Delivered in groups of up to five people in 1.5-hour sessions over the course of two weeks. Main outcome measures: Primary outcomes - rate of recruitment, follow-up, and feasibility to deliver the intervention. Secondary outcomes included measures of depression, general mental health, and coping strategies. Results: 129 male prisoners were screened, 64 were randomly allocated, with a mean age of 53.5 years (SD 14, range 23-84). 59 (95%) prisoners were of Polish origin. Our recruitment rate was 48%. There was differential follow up with those in the intervention group less likely to complete the post-test battery versus those who received care as usual. Outcome measures were successfully collected at both time points. Conclusions We were able to recruit, retain and deliver the intervention within the prison setting; some logistical challenges limited our assessment of intervention engagement. Our data helps to demonstrate how use of the RCT study design can be implemented and delivered within the complex prison environment. Trial registration number ISRCTN 70138247, protocol registration date May 2021