Associations between patient characteristics at referral and social worker care coordinator allocation in mental healthcare: a retrospective cohort study.

Objectives: To investigate care coordination delivered specifically by social workers and, more generally, by other professionals using electronic health records. Study design and Setting: A retrospective cohort study in a large mental healthcare provider serving a South London catchment. Sample: The study comprised care coordination episodes from 2007-2023 for adults aged 18-65 years at the time of commencement. We categorised these by the care coordinator's profession: social worker, nurse, doctor, and others, with a focus in the analysis on social worker care coordination. In addition to sociodemographic data, we obtained diagnosis, mental health service use, and symptoms over the 12 months preceding episode start. Outcome measures: Social workers' associations with mental healthcare service use 12 months before the episode start. Cases allocated to social workers the year after had higher rates across most service-use outcomes. Results: Of 327,056 care coordination episodes for 132,553 patients, 10.6% had a social worker care coordinator. Full-adjusted associations with social worker care coordinator included longer duration since first referral (IRR 1.05, 95% CI 1.03-1.07, P <0.001), more prior hospitalisations involving compulsory detention (1.11, 1.07-1.15, P <0.001), more days under a home treatment team (1.25, 1.17-1.34, P <0.001), and more emergency department mental health contacts (1.10, 1.07-1.14, P <0.001), as well as higher recorded symptoms on all scales. Conclusion: Episodes with social workers as care coordinators are associated with more complex needs, severe symptoms and a later stage in the course of care. The assignment of care coordinators by profession and its influence on clinical outcomes remain unclear; further mixed-methods research could help clarify this.