<p>Characteristics of included studies.</p>

Studies that contributed information on context and mechanisms of action for electronic signposting to cancer prevention interventions for adults in any healthcare setting were included. Studies were assessed for quality based on relevance, richness and rigour. Realist synthesis and input from stakeholders, including patients, was used to aid development of our novel programme theory.

Thirty studies were included, 26 of which were conducted in the United States. 57 individual context-mechanism-outcome configurations were identified. For patients, memorable messages using wording tailored to patient characteristics, and use of a popular communication channel (e.g., SMS text) improved ‘buy-in’ and usability. For providers, a good fit with organisational priorities, workflow, and establishing compatibility with existing technical systems was important.

Increasing optimism of technology and ensuring electronic signposting did not risk existing patient-provider relationships were also key to success. To reduce cancer and cancer disparities, policymakers and providers need to implement electronic signposting in ways that promote ‘buy-in’, ensure perceived usability, and nurture positive attitudes towards technology. The field would benefit from further qualitative insight, health economic analysis, exploration of equity and long-term outcomes, and research in non-USA contexts.

Protocol registration: PROSPERO [CRD42024586907].</p></div>