About the Study

Find out more about the APPLE-Tree Study



Study aims

Phase 1: To test whether the APPLE-Tree intervention is acceptable and feasible to deliver in practice, and explore how we might increase acceptability and feasibility by adapting the intervention before phase 2.

Phase 2:

Primary: To conduct a randomised controlled trial to evaluate the clinical effectiveness (in terms of reducing cognitive decline) of the APPLE-Tree intervention in individuals at high risk of dementia with mild cognitive impairment (MCI) or subjective cognitive decline (SCD) at 24-month follow-up.

Secondary: To evaluate the cost-effectiveness of the APPLE-Tree intervention in individuals with MCI or SCD at 24-month follow-up.

Process evaluation: To explore how the intervention was implemented (to include fidelity, dose and reach) and any mechanisms of impact which produce behavioural and lifestyle changes during and beyond the facilitated sessions investigate.

Phase 3 (Implementation):

To explore what factors may determine decisions of NHS and third sector organisations who are not taking part in the trial, regarding whether they decide to adopt the new intervention, if it is demonstrated to be clinically effective and cost-effective.


What will happen in the study?

For those who agree to take part in this study, they will be invited to talk to a researcher in a place they choose (we can come to their home or meet them at our centre). This visit will take around 1 hour and a half. We will ask people taking part to complete questionnaires, including a memory test and give a voluntary blood sample. We will also talk to a relative/friend.

After this, the researcher will contact participants again to tell them if they have been randomly allocated to receive the new programme or to receive written information about dementia prevention and information for services only.

The researcher will meet participants again at 12 months and 24 months to repeat the assessments, including the blood test if they agree to this. We may also invite some participants to take part in a separate, qualitative interview if they received the new programme, to learn about their experience of the sessions and get feedback


APPLE-Tree intervention

We will invite participants allocated to receive the new programme to attend ten group sessions over a 6-month period. We will offer individual sessions for people who cannot come to groups. Two facilitators will lead the groups.

Our programme will help older people make changes that can prevent dementia. These are:

1. Being more socially and mentally active

2. Eating more healthily

3. Being more physically active

4. Looking after their mental and physical health

5. Stopping smoking

6. Reducing alcohol



We are looking for people who are:

  • Aged 60+
  • They or someone else has some worries about their memory
  • They don’t have dementia
  • A relative, friend or professional in at least monthly contact who is able and willing to act  as an informant


The study is taking place at sites within two hours of London or Essex.

To find out more, please see the Resources section of the website or email us on (APPLE-Tree website).