“Tailored” refers to customizing multidomain interventions to the specific needs and context of the individual or population. This includes selecting components that address relevant modifiable risk factors that are present in a person; adjusting intensity and delivery format; and considering cultural, socioeconomic and resource constraints. Tailoring ensures that interventions are adapted to optimize feasibility, adherence and effectiveness. “Multidomain” refers to targeting multiple dementia risk factors at once. Dementia risk factors should be addressed holistically, because multiple risks often coexist and accumulate over the life course.

y Multidomain interventions address three or more risk factors or domains aimed at reducing the risk of cognitive decline and/or dementia. They typically focus on promoting healthy behaviours such as physical activity, cognitive stimulation and dietary improvements; they may also include optimization of pharmacological management for cardiovascular and metabolic risk factors (253). y Although reported effect sizes were very small, even modest improvements can translate to substantial health benefits when implemented at scale. y People with MCI may benefit the most from multidomain interventions, and although the benefits are modest, they can slow cognitive decline and help individuals to preserve independence for longer. y Evidence is emerging for structured interventions tailored to individual risk profiles, highlighting the importance of personalization in design and delivery. y Multidomain interventions should be tailored by adapting components to an individual’s risk profile, preferences and local context. This includes selecting the most relevant health-related behaviour targets such as physical activity, diet, cognitive training or management of health conditions (e.g. management of vascular risk) based on a person’s health status and needs. y Health care professionals should provide comprehensive advice and education on how to address multiple risk factors in an integrated manner, promoting holistic health and reducing overall risk beyond cognitive outcomes. y Multidomain interventions can be adapted to different cultural and socioeconomic contexts, but they need to be tailored for feasibility and acceptability. This includes alignment with local context, risk profiles and cultural norms. y Implementation should prioritize populations with modifiable risk factors and ensure equity in access, particularly in low-resource settings. y Successful implementation requires adequate training of health care providers and community workers to deliver interventions effectively and consistently, including building capacity for behaviour change strategies to enhance adherence and long-term engagement. Community engagement is critical for sustainability. y Integration into existing health systems and ageing programmes is essential to ensure institutional support and scalability, given the overlap with NCD prevention strategies. Intersectoral partnerships across health, social care, education and community sectors are needed to address multiple risk factors comprehensively. y Digital and hybrid delivery models may improve scalability but they need to address barriers related to digital literacy and access. When using digital tools, compliance with data protection regulations and ethical standards must be ensured. y Costs vary widely, depending on intervention design and resource intensity; potential cost savings extend beyond dementia prevention to other chronic conditions. y Creating supportive environments (e.g. safe spaces for physical activity and access to healthy foods) can reinforce individual-level interventions. Policy and financing frameworks should integrate dementia risk reduction into urban planning, clean air initiatives, health promotion, NCD prevention and healthy ageing strategies, to enable sustainable scale-up.