ENHANCE: Feasibility and acceptability trial of a coach-supported app to prevent dementia

Sergi Costafreda1,2, James Jamison1, Tsz Kiu Clare Yu1, Louise Allan3, Richard Boczko4, Sue Boex, Youngjun Cho1, Andrea Hilton4, Rachael Hunter1, Fahima Khatun1, Teresa Lee1, Monica Manela1, Louise Marston1

,

Vrushti Mehta1, Naaheed Mukadam1, Hee Kyung Park1, Greta Rait1, Penny Rapaport1,2, Joanne Reeve4, Anne Schilder1, Aneesha Singh1, Andrew Sommerlad1,2, Elizabeth Steed5, Jing Yi Weng1, Gill Livingston1,2

1 University College London; 2 North London NHS Foundation Trust; 3 University of Exeter; 4 University of Hull; 5 Queen Mary University of London

Background

• Dementia risk may be reduced by addressing modifiable risk factors.

• These risks cluster in people with less education, lower socio-economic status and

ethnic minority background. These groups are under-represented in prevention

research.

The ENHANCE Intervention

• A blended eHealth intervention with coach plus app, delivering a personalised 3-

month programme across risk factors assessed at baseline.

• Face-to-face onboarding; participants choose up to 3 risk factors, 6 weeks each.

• Weekly app content: brain-training games, videos and self-monitoring questionnaires

• Fortnightly meetings with a trained non-specialist coach

Risk Factors Targeted

High Blood Pressure (SYS/DIAS>140/90) Obesity (BMI>30) Smoking (≥ 7 cigarettes in past week) Depression (PHQ-9 ≥ 9) Social isolation (LSNS-6 < 6) High Blood sugar (HbA1c ≥ 48 mmol/mol)

Physical inactivity (< 150 min/week)

Alcohol (> 14 units/week)

Hearing loss (HearWHO screen + no hearing aid)

Low Education (Left school ≤ 16 or no qualifications)

The ENHANCE App

Methods

• Two-arm, individually randomised feasibility trial; 2:1 allocation: ENHANCE vs care as

usual.

• Recruited through GP practices and community settings, with focus on people living in

the 40% most deprived areas.

• Sites in London, North-East and North-West England, Cardiff and Southampton.

• Baseline and 3-month nurse assessments included behavioural, clinical and NIH Toolbox

• Assessors at 3 months: blinded to allocation; coaches and participants: not blinded.

Eligibility

• Aged 60-80, living in the community, without a dementia diagnosis

• Registered with a GP and able to consent.

• Having three or more of the 10 modifiable risk factors according to our baseline

assessment.

Participant Flow

Progression criteria- All GREEN

• Adherence: engaged outside coaching at least fortnightly over two-thirds of

intervention window.

• Primary outcome: NIH Toolbox cognition battery collected.

• Process evaluation: 42 dual-rated coaching sessions across 25 participants, 17

coaches and 7 sites. Acceptability questionnaire, interviews.

Reaching the underserved

Acceptability questionnaire (n=35)

Personalised coaching

plus app content Managing Blood Pressure

module Games and activity

rewards

More reserved views on in-app messaging (69%) and videos (77%); both are targeted in

the planned app update before main RCT.

Self-monitoring and app prompts Rewards for weekly activities

Aims

Recruitment and Reach

Qualitative follow up interviews

• Determine feasibility of a full RCT of the ENHANCE intervention.

• Determine acceptability to participants and whether it is deliverable by staff.

• Estimate recruitment, uptake, engagement, adherence and retention at 3 months

• Exceeded target: 66 randomised (target 60), 110%, across 8 sites in 6 regions.

• Recruitment accelerated from 0.8 to 4.9 participants/week after a Sept 2025 eligibility

amendment and the addition of community recruitment.

• Last patient last visit for 3-month follow-up was 28 May 2026.

"I really liked the games... I

really enjoyed those."

Participant 1-003

"I think she was actually

the key to the whole

system working."

Participant 1-005

"I think it [coaching]

helped me to be a better

practitioner."

Coach, site 5

Conclusions on Feasibility and Acceptability: ENHANCE met all pre-specified progression criteria, reached underserved groups, and was acceptable to participants and delivery staff

66

91%

65%

100%

Randomised

Target 60; recruited across 8 sites in 6 regions

Retained

60/66 followed up at 3 months

Living in 40% most deprived areas

Index of Multiple Deprivation - deciles 1-4

Coach advice useful; goal-setting useful

Acceptability questionnaire, n=35

What is being refined before the main RCT

• Coaching support and tracker-informed feedback, keeping the coach-app loop central.

• In-app messaging and videos

Why this matters

• The feasibility trial tested whether ENHANCE can be delivered in real services.

• Recruitment through GP practices and community settings improved reach.

• The main RCT can now test whether sustained multidomain support changes cognition.

Main RCT pathway

• Planned sample: 588 participants UK-wide.

• Planned intervention: 12-month app with coaching support.