Lay summary
Around 33,000 people in Aotearoa New Zealand live on the Supported Living Payment (SLP) because of psychological or psychiatric problems. They are among the most disadvantaged people in Aotearoa New Zealand, so increasing their wellbeing would have a strong impact on health equity. Their low income exposes many to conditions that may exacerbate mental and physical health issues and impede their recovery. We want to design a randomised controlled trial to assess whether increasing their incomes would improve the health and wellbeing of this group of people. We will consult with people with ongoing mental health problems, other stakeholders, and researchers, review existing literature, investigate data availability in the IDI, and trial questionnaires, to ensure that the study is acceptable, responsive to the needs of participants and other stakeholders, to identify meaningful and measurable outcome measures, and to estimate required sample size.