5. Future study design.

Study design	Study design	Recommendation
Setting		Primary care and community mental healthcare services
Method	Duration	Minimum of 12‐month follow‐up
	Allocation	Randomised (cluster or individual)
	Blinding	Blinding of outcome assessors Blinding of statisticians Allocation concealment
	Outcomes	Psychiatric admissions Intervention costs Quality of life Mental state Social functioning Personal recovery Adverse effects, e.g. acute mental health episodes (defined as number of crises in time period) Process outcomes Experience of care/satisfaction Fidelity Core outcome set for bipolar I and II (Retzer 2020)
	Retention	Utilise participant retention strategies
	Analysis	Produce and report analysis plans prior to research being conducted
Participants	Diagnosis	Severe mental illness
	Age	18+ (or younger if in receipt of adult services)
	Gender	All
	N	300+
Intervention		Collaborative care according to Gunn 2006 description to include: Multidisciplinary working (which includes primary care) Enhanced communication between providers (e.g. via case manager, multidisciplinary team meetings) Scheduled and proactive follow‐up Delivery of evidence‐based treatment according to algorithms/protocols