Trial Design, Sample Size, and Participating Clinical Sites
psychotic disorders, chronic psychotic disorders, ’
The IFIP trial employed a cluster randomised controlled design. A cluster was defined as one or more CMHC outpatient units that had the main responsibility for long-term treatment of patients with psychotic disorders in a discrete catchment area. There were no further eligibility criteria for clusters. The design was appropriate to analyse differences in implementation outcomes between experimental and control conditions, but also critical to avoid contamination in the sub study on patients’ and relatives’ outcomes (Hestmark et al., Adherence to the national guidelines was assessed through fidelity measurements. The unit of analysis was the cluster, and fidelity outcomes pertain to the cluster level. When calculating the sample size, we assumed a mean difference in fidelity scores of 1.82 with a standard deviation of 0.80, after 18 months of implementation support. These numbers were based on the results from two previous implementation studies using the family psychoeducation fidelity assessment (FPE) scale (Kealey et al., All the 16 CMHCs in five counties of the South-Eastern Norway Regional Health Authority were invited to participate in the trial, and 15 clinical sites from 12 CMHCs in 6 health trusts agreed to participate during summer/fall 2018. These 12 CMHCs together serve approximately 25% of the Norwegian population. Among the remaining CMHCs, the principal reason given for non-participation was a lack of capacity to take part in a research project. The participating clinical sites included various adult service types, such as assertive outreach teams, early intervention units, dual diagnosis teams, as well as mixed or specialised outpatient clinics. Their clients were 18 years or above, and included both patients with recently diagnosed and chronic psychotic disorders. A detailed account of the participating clinical sites and their baseline fidelity scores has been published (Hestmark et al., 