2.1. Study design
The effectiveness evaluation of the FOCS intervention was carried out as a non-randomised and non-blinded pragmatic controlled study during 2019–2020. It was not possible to randomise group allocation due to the structure of how the Swedish Prison and Probation Service (SPPS), responsible for all Swedish prisons, is organised. The SPPS is a state authority for which yearly directives, including funding and core activities, are given by the Swedish government. Based on the government’s directive, the SPPS further provides instructions and funding to each prison yearly. The prison subsequently prepares an operation and economic planning for the year ahead, which includes all activities that are to be conducted in the specific prison during the coming year. At the time of this study, the plannings of the prisons were already finalized and thus stated whether a prison would carry out FOCS or not. Therefore, group allocation was based on the set operation planning at each prison. Thus, the prisons that agreed to participate in the study and where FOCS was carried out during the study period, in accordance with the operation planning, were included in the intervention group, whereas prisons that agreed to participate in the study and that planned for FOCS later on were included in the control group. No matching of groups was performed. A study protocol which described the evaluation of the intervention has been published and this reporting of the trial follows the TREND guidance [