Protocol for 'Re: CBT Dialysis': a realist evaluation-why, for whom and in what circumstances does cognitive behaviour therapy work for people with depressive symptoms receiving dialysis?

Introduction: Nearly 40% of adults receiving life-saving dialysis for kidney failure report depressive symptoms. With more than 40 000 Canadians on dialysis, this is a significant health burden. Cognitive behavioural therapy (CBT) has been shown to be effective for treating depressive symptoms; however, it is rarely considered or used for people receiving dialysis. The aim of this realist study is to evaluate and explain how, why, for whom and in what circumstances therapist-guided and remotely delivered CBT works in order to provide equitable mental healthcare to individuals with depressive symptoms receiving dialysis.

Methods and analysis: The project will include a realist synthesis, a quantitative cohort study and a realist evaluation. Realist methodology is a theory-driven approach that seeks to explain how generative mechanisms are shaped by contextual features, giving rise to outcome patterns. We will begin by developing an initial programme theory (IPT) from the literature and interviews with CBT therapists to understand how CBT is intended to work and for whom. We will use data from the quantitative cohort study to identify contexts that may shape outcome patterns in CBT for people receiving dialysis. This includes previously collected survey data and data from a longitudinal cohort study, both sourced from people across Canada undergoing dialysis. We will test and refine the IPT using data from a realist evaluation and existing literature. The realist evaluation will involve participants from the quantitative cohort study who received therapist-guided, remotely delivered CBT.

Ethics and dissemination: Ethical approvals have been granted. We have planned a wide range of dissemination strategies: journal manuscripts and conference presentations, executive memos for administrators of renal programmes in Canada, an online inventory of resources for depressive symptoms and presentations of findings together with patient partners at all participating sites.

Prospero registration number: CRD42023476184.