Tailored Brain Health Insights Through Nurturing Knowledge-based Change - Stakeholder-driven, Human-centered, AI-powered Refinement for Prevention (THINK-SHARP)

Dementia represents a growing public health challenge in Singapore and across the Asia-Pacific region, with prevalence projected to rise substantially as the population ages. Up to 40% of dementia risk is attributable to modifiable lifestyle factors, highlighting significant potential for prevention through targeted behavioural interventions. Despite this, translating evidence-based lifestyle recommendations into sustained behavioural change in community settings remains a significant challenge, particularly given the limited time available for personalised guidance in primary care.

The THINK-SHARP trial evaluates BLAZE (Brain health Lifestyle Action with personaliZed Engagement), a theory-driven AI-powered digital coaching intervention designed to support brain health behaviours in community-dwelling adults. BLAZE is grounded in the Capability-Opportunity-Motivation-Behaviour (COM-B) framework, a well-established behavioural science model, and is delivered via a WhatsApp-based platform integrated with a large language model (LLM). The intervention operates through four integrated modules - Assessment, Education, Nudge, and Coaching - to deliver personalised recommendations, behavioural prompts, and goal-setting support tailored to each participant's individual brain health profile.

Personalisation is driven by the Brain Care Score (BCS), a validated composite measure of modifiable physical, lifestyle, and social-emotional risk factors for brain health. BLAZE uses each participant's BCS profile to identify priority areas for behavioural change and generates adaptive, data-driven recommendations accordingly. All content is informed by a curated knowledge base developed in collaboration with neurologists and geriatricians to ensure clinical relevance and safety.

The trial employs a two-arm, waitlist-controlled randomised controlled trial (RCT) design, with 350 participants randomised 1:1 to either the immediate intervention arm or the waitlist control arm. The immediate intervention arm receives BLAZE for 12 months, while the waitlist control arm receives usual care for the first 6 months before crossing over to receive BLAZE for a further 6 months. The primary outcome is the between-group difference in BCS at 6 months. Secondary outcomes assess changes across six domains: physical function, lifestyle behaviours, self-management and health engagement, cognitive function, quality of life, and social health.

Beyond clinical effectiveness, the trial incorporates a concurrent process evaluation to assess implementation outcomes including adherence, feasibility, usability, and perceived value of the intervention. A model-based health economic evaluation will also be conducted to estimate the long-term cost-effectiveness of BLAZE from the Singapore public healthcare payer perspective. Together, these components provide a comprehensive assessment of BLAZE's potential as a scalable, behaviourally grounded approach to community brain health promotion.