Introduction Palliative Systemic Treatment (PST) (chemotherapy, immunotherapies, targeted therapies) and palliative radiotherapy (PR) can be offered to patients with advanced incurable cancer to slow cancer growth and relieve symptoms. However, PST can cause increased toxicities and treatment related mortality, poor quality of life, and inefficient use of resources. Palliative and supportive care can be offered alongside or as an alternative option to active treatments to reduce symptom burden and improve well-being. Palliative treatment and care decision making is enhanced by Healthcare Professionals (HCP’s) eliciting and incorporating patients’ preferences through shared decision making (SDM) approaches.

We aimed to identify contextual factors and mechanisms that influence patients’ experiences in decision-making, when supported by patient aids and SDM interventions.

Methods A realist review was conducted to identify, appraise, synthesise and analyse research evidence. Subsequently, a list of theories was developed explaining connections between contexts, mechanisms and outcomes, then synthesised to create a programme theory.

Results Theories from 33 papers were integrated into a programme theory (figure 1). This explains how contexts including patients‘ experiences and attitudes and HCP’s’ approaches, interact with mechanisms, e.g. providing adequate time, accessible information, palliative care expertise and opportunities to prepare for and revisit decisions. These contexts and mechanisms influenced patient decisional satisfaction, conflict and regret.

• Download figure
• Open in new tab
• Download powerpoint

Abstract 175 Figure 1

Discussion To improve patients’ decision-making experiences adequate time and support HCPs should be provided to engage with accessible information and reflect on their preferences.

Conclusion This programme theory can inform improvements in communication and treatment decision-making for patients with advanced incurable cancer.