Collaborative care intervention for individuals with severe mental illness: the PARTNERS2 programme including complex intervention development and cluster RCT
Authors: Plappert Humera , Byng Richard , Reilly Siobhan Theresa , Hobson-Merrett Charley , Allard Jon , Baker Elina , Britten Nicky , Calvert Melanie , Clark Michael , Creanor Siobhan , Davies Linda , Denyer Rebecca , Frost Julia , Gask Linda , Gibbons Bliss , Gibson John , Gill Laura , Gwernan-Jones Ruth , Hosking Joanne , Huxley Peter , Jeffery Alison , Benjamin Jones  , Keeley Tom , Laugharne Richard , Marwaha Steven , Planner Claire , Rawcliffe Tim , Retzer Ameeta , Richards Debra , Sayers Ruth , Williams Lynsey , Pinfold Vanessa , Birchwood Maximillian 
Published: July 2024

Background and aims
Individuals living with severe mental illness such as schizophrenia and bipolar can have significant emotional, cognitive, physical and social challenges. Most people with severe mental illness in the United Kingdom do not receive specialist mental health care. Collaborative care is a system of support that combines clinical and organisational components to provide integrated and person-centred care. It has not been tested for severe mental illness in the United Kingdom. We aimed to develop and evaluate a primary care-based collaborative care model (PARTNERS) designed to improve quality of life for people with diagnoses of schizophrenia, bipolar or other psychoses when compared with usual care.

Methods
Phase 1 included studies to (1) understand context: an observational retrospective study of primary and secondary care medical records and an update of the Cochrane review ‘Collaborative care approaches for people with severe mental illness’; (2) develop and formatively evaluate the PARTNERS intervention: a review of literature on collaborative care and recovery, interviews with key leaders in collaborative care and recovery, focus groups with service users and a formative evaluation of a prototype intervention model; and (3) develop trial science work in this area: a core outcome set for bipolar and recruitment methods. In phase 2 we conducted a cluster randomised controlled trial measuring quality of life using the Manchester Short Assessment of Quality of Life and secondary outcomes including time use, recovery and mental well-being; a cost-effectiveness study; and a mixed-methods process evaluation. Public involvement underpinned all of the workstream activity through the study Lived Experience Advisory Panel and the employment of service user researchers in the project team.

Results phase 1
The study of records showed that care for individuals under secondary care is variable and substantial and that people are seen every 2 weeks on average. The updated Cochrane review showed that collaborative care interventions were highly variable, and no reliable conclusions can be drawn about effectiveness. The PARTNERS model incorporated change at organisational, practitioner and individual levels. Coaching was selected as the main form of support for individuals’ personal goals. In the formative evaluation, we showed that more intensive supervision and ‘top-up’ training were needed to achieve the desired shifts in practice. A core outcome set was developed for bipolar, and measures were selected for the trial. We developed a stepped approach to recruitment including initial approach and appointment.

Results phase 2
The trial was conducted in four areas. In total, 198 participants were recruited from 39 practices randomised. Participants received either the PARTNERS intervention or usual care. The follow-up rate was 86% at 9–12 months. The mean change in overall Manchester Short Assessment Quality of Life score did not differ between the groups [0.25 (standard deviation 0.73) for intervention vs. 0.21 (standard deviation 0.86) for control]. We also found no difference for any secondary measures. Safety outcomes (e.g. crises) did not differ between those receiving and those not receiving the intervention. Although the costs of intervention and usual care were similar, there is insufficient evidence to draw conclusions about the overall cost-effectiveness of PARTNERS. The mixed-methods process evaluation demonstrated that a significant proportion of individuals did not receive the full intervention. This was partly due to care partner absence and participant choice. The in-depth realist informed case studies showed that participants generally appreciated the support, with some describing having a ‘professional friend’ as very important. For some people there was evidence that delivery of the intervention had led to specific personal changes.

Strengths and limitations
The phase 1 records study provided insights into usual care that had not been previously documented. The realist informed complex intervention development was both theoretical and pragmatic. The trial continued through the COVID-19 pandemic with high levels of follow-up. The process evaluation had the depth to explore individual changes in participants’ response to the intervention. Weaknesses in the trial methodology included suboptimal implementation, outcome measures that may not have been sensitive to changes patients most appreciated and difficulties collecting some outcomes.

Conclusions
While PARTNERS was not shown to be superior to usual care, the change to PARTNERS care was not shown to be unsafe. Full intervention implementation was challenging, but this is to be expected in studies of care that include those with psychosis. Some individuals responded well to the intervention when psychological support in the form of individualised goal setting was flexibly deployed, with evidence that having access to a ‘professional friend’ was experienced as particularly helpful for some individuals.

Future work
Key components of the PARTNERS model could be developed further and tested, along with improved supervision in the context of ongoing community mental health care change.

Trial registration
This trial is registered as ISRCTN95702682.

Funding
This award was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research programme (NIHR award ref: NIHR200625) and is published in full in Programme Grants for Applied Research; Vol. 12, No. 6. See the NIHR Funding and Awards website for further award information.