Individuals living with severe mental illness can have significant emotional, physical and social challenges. Collaborative care combines clinical and organisational components.

We tested whether a primary care-based collaborative care model (PARTNERS) would improve quality of life for people with diagnoses of schizophrenia, bipolar disorder or other psychoses, compared with usual care.

We conducted a general practice-based, cluster randomised controlled superiority trial. Practices were recruited from four English regions and allocated (1:1) to intervention or control. Individuals receiving limited input in secondary care or who were under primary care only were eligible. The 12-month PARTNERS intervention incorporated person-centred coaching support and liaison work. The primary outcome was quality of life as measured by the Manchester Short Assessment of Quality of Life (MANSA).

We allocated 39 general practices, with 198 participants, to the PARTNERS intervention (20 practices, 116 participants) or control (19 practices, 82 participants). Primary outcome data were available for 99 (85.3%) intervention and 71 (86.6%) control participants. Mean change in overall MANSA score did not differ between the groups (intervention: 0.25, s.d. 0.73; control: 0.21, s.d. 0.86; estimated fully adjusted between-group difference 0.03, 95% CI −0.25 to 0.31; P = 0.819). Acute mental health episodes (safety outcome) included three crises in the intervention group and four in the control group.

There was no evidence of a difference in quality of life, as measured with the MANSA, between those receiving the PARTNERS intervention and usual care. Shifting care to primary care was not associated with increased adverse outcomes.

There is global interest in the reconfiguration of community mental health services, including primary care, to improve clinical and cost effectiveness.

This study seeks to describe patterns of service use, continuity of care, health risks, physical healthcare monitoring and the balance between primary and secondary mental healthcare for people with severe mental illness in receipt of secondary mental healthcare in the UK.

We conducted an epidemiological medical records review in three UK sites. We identified 297 cases randomly selected from the three participating mental health services. Data were manually extracted from electronic patient medical records from both secondary and primary care, for a 2-year period (2012–2014). Continuous data were summarised by mean and s.d. or median and interquartile range (IQR). Categorical data were summarised as percentages.

The majority of care was from secondary care practitioners: of the 18 210 direct contacts recorded, 76% were from secondary care (median, 36.5; IQR, 14–68) and 24% were from primary care (median, 10; IQR, 5–20). There was evidence of poor longitudinal continuity: in primary care, 31% of people had poor longitudinal continuity (Modified Modified Continuity Index ≤0.5), and 43% had a single named care coordinator in secondary care services over the 2 years.

The study indicates scope for improvement in supporting mental health service delivery in primary care. Greater knowledge of how care is organised presents an opportunity to ensure some rebalancing of the care that all people with severe mental illness receive, when they need it. A future publication will examine differences between the three sites that participated in this study.