Discussion
Cognitive remediation provided either in a Group or One-to-One was more beneficial at post treatment than TAU, but the benefits were reduced at follow-up. There were few differences between these CR methods in terms of costs or cost-effectiveness, and the treatment costs (therapist time) in comparison to the overall health service costs. Both types of provision are therefore recommended. The interventions may entail extra initial investment compared to usual care. However, the health economic results show that overall costs do not differ much from usual care due to cost offsets elsewhere in the system. This is crucial to consider when investigating potentially expensive interventions. QALYs were significantly higher compared to usual care and the probability of either being more cost-effective than usual care was high.Anecdotal evidence while we were recruiting suggested that the group option was less popular, and there were more people who dropped out of this condition suggesting that more encouragement might be needed to engage in this intervention method. After removing dropouts there were few adherence differences or meeting the minimal 20-session dose between group and one-to-one. This suggests that, once people were engaged, group treatment was equally acceptable (Fewer therapy hours may have contributed to the poor results in the independent arm as they received fewer sessions and hours of therapy than the other CR arms (While the cost and QALY differences were not statistically significant between the treatment arms, the approach used in the economic analyses focuses on the probability that one intervention is more cost-effective than another. Here we found that both Group and One-to-One had a high probability of being more cost-effective than TAU, and the corresponding ICERs were below the lower threshold used by UK NICE (£20 000) for the adoption of a new NHS therapy. The ICER for Group CR vs One-to-one was substantially higher although below the upper threshold of £30 000.The CR benefits wane, and although present, are no longer statistically significant at 6-month follow-up. We embedded the transfer of skills to real-world activities within the CIRCuiTS software with exercises for using a bus, cooking, or shopping as well as homework activities to aid transfer. However, COVID-19 might have had an impact on outcomes for a minority as opportunities to fulfill some GAS-defined recovery goals were unavailable when social distancing and lockdown were implemented in the United Kingdom. We had 25 post therapy (17 Group, 11 One-to-One) and 40 (18 Group and 22 One-to-One) follow-up assessments that occurred after the beginning of the pandemic (March 16, 2020). These results are therefore likely to be the minimum rather than the maximum of what might have been achieved. In addition we only included a handover note to the local EIS team on CR outcomes, and perhaps if we had included joint sessions with other healthcare professionals (like the Thinking Skills for Work programme