Background People with serious mental illnesses (SMI) such as schizophrenia often also have physical health illnesses and interventions are needed to address the resultant multimorbidity and reduced life expectancy. Research has shown that volunteers can support people with SMI. This protocol describes a feasibility randomised controlled trial (RCT) of a novel intervention involving volunteer ‘Health Champions’ supporting people with SMI to manage and improve their physical health. Methods This is a feasibility hybrid II randomised effectiveness-implementation controlled trial. The intervention involves training volunteers to be ‘Health Champions’ to support individual people with SMI using mental health services. This face-to-face or remote support will take place weekly and last for up to 9 months following initial introduction. This study will recruit 120 participants to compare Health Champions to treatment as usual for people with SMI using secondary community mental health services in South London, UK. We will measure the clinical and cost effectiveness including quality of life. We will measure the implementation outcomes of acceptability, feasibility, appropriateness, fidelity, barriers and enablers, unintended consequences, adoption and sustainability. Discussion There is a need for interventions to support people with SMI with their physical health. If this feasibility trial is successful, a definitive trial will follow to fully evaluate the clinical, cost and implementation effectiveness of Health Champions supporting people with SMI. Trial registration ClinicalTrials.gov, registration no: NCT04124744.

6115 Background: We reported underrepresentation of TYA in CTT in England, 2005-06. Since 2005 national healthcare policies and research initiatives aimed at increasing participation of TYA in CCT have been implemented. We aimed to determine if this has improved accrual rates (AR). Methods: We analyzed accrual by age during 2005-2010 to UK Cancer Research Network interventional trials recruiting newly diagnosed patients (pts) with leukaemia, lymphoma, bone/soft tissue sarcoma, central nervous system and germ cell tumours. AR were expressed as the ratio of pts entered onto trial compared to population incidence cases for 2005-08; for 2009-10, mean incidence of 2005-08 was used. Results: 2005-10 showed an AR increase of 10.3% for pts 10-14 yrs, 17.9% for pts 15-19 yrs but only 4.6% for pts 20-24 yrs (Table). In 2010 AR was 54.4% for pts 10-14 yrs, 43.3% for 15-19 yr olds and 20.6% for pts 20-24. Annual increases of AR were observed for pts 15-19 yrs, but in no other age groups, 0-59 yrs. We looked at AR for children and younger teenagers , 5-14 yrs, vs older TYA, 15-24 yrs. Overall, AR for 5-14 yr olds was greater, 53.7% vs 23.0% for pts 15-24 yrs; however, during 2005-10 AR increased by 9.7% for pts aged 15-24 compared to 7.8% for pts aged 5-14. Conclusions: AR for TYA has improved in between 2005-10. Most benefit is evident for older teenagers; AR for young adults remain disappointing. Changes relate to increased trial availability and access, centralisation of care for TYA, amendments to age eligibility criteria to reflect tumour biology and increased collaboration between adult and paediatric clinical research groups. Strategies to improve AR for young adults require further development. [Table: see text]