Efficacy of a Multidomain Intervention on Lifestyle Risk Factors for Dementia Prevention

The primary endpoint is the number of participants showing a clinically significant change (CSC) from Screening to Week 24 in at least one eligible domain (cognitive engagement, physical activity, mediterranean diet adherence).

Cognitive engagement is measured using the Vemuri Cognitive Activity Questionnaire. Participants are asked to indicate the frequency in which they engage in 10 types of cognitive leisure activities. Scores range from 0 to 70. A higher score represents a higher cognitive engagement level. A clinically significant change is defined as a 6-point minimum increase.

Physical activity is measured using the modified Godin-Shephard Leisure Time Physical Activity Questionnaire which consists of three sets of questions (6 items). An overall physical activity score is computed in Metabolic equivalent tasks (MET)-minutes/week, as well as a moderate-to-vigorous physical activity (MVPA) score. A higher MET value represents a higher physical activity level. A clinically significant change is defined as a 300 MET-min/week minimum increase in the MVPA score.

Adherence to the Mediterranean Diet is measured with an adaptation of the Canadian Mediterranean Diet Scale. The scale consists of 13 questions on food consumption frequency and intake habits. Scores range from 0 to 13, where a higher score represents a higher adherence level. A clinically significant change is defined as a 2-point minimum increase.

Quality of life is measured with the SF-12v2, a 12-item questionnaire.

Cognitive Performance is assessed using the Creyos Dementia Assessment, a computer-administered cognitive test battery that includes 6 tasks measuring 3 cognitive domains (memory, reasoning and verbal abilities). Several scores are calculated: one for each of the 6 individual tests, one for each of the 3 cognitive domains, as well as an overall score. Higher scores indicate higher cognitive performance.

The CAIDE (Cardiovascular risk factors, aging, and incidence of dementia) is a multifactorial risk estimation scale using age, hypertension, hypercholesterolemia, physical activity level, obesity (BMI), and educational level. A higher score indicates a higher risk of dementia.

Perceived stress is investigated using a single question answered on a 5-item Likert scale where a higher score indicates a higher stress level.

Sleep quality is assessed using a single question taken from the Pittsburgh Sleep Quality Index. The score is derived from a 4-point Likert scale where a higher score indicates worse sleep quality.

Anxiety symptoms over the past 2 weeks are assessed using the Generalized Anxiety Disorder (GAD-7) Scale which comprises 7 items which are scored "0" (Not at all) to "3" (Nearly every day) for a maximum total score of 21. A higher score indicates higher anxiety symptoms.

Current memory concerns are evaluated with a single 3-item question.

Readiness to change is assessed for each of the 3 intervention domains using a question with five answer options.

Self-efficacy is evaluated with the General Self-Efficacy (GSE) Scale which consists of 10 items which are scored from "1" (Not True At All) to "4" (Exactly True) for a maximum score of 40. A higher score indicates greater self-efficacy.

Motivations are assessed via the Treatment Self-Regulation Questionnaire (TSRQ), which assesses different forms of motivation. It consists of 15 items, each rated on a 7-point scale ranging from 1 (not at all true) to 7 (very true). The items are combined into 4 subscales, for which 4 subscores can be calculated. Each subscore ranges from 1 to 7, with a higher subscore indicating higher importance of that form of motivation.

Dementia literacy is assessed using 20 questions answered using 5-point Likert scales for a maximum score of 100. A higher score indicates better dementia literacy.

Perceived progress will be measured with one question rated on a 5-point Likert scale for each intervention domain.

In the Luci Cognitive Engagement Questionnaire, 14 types of cognitively stimulating leisure activities are provided, and participants are asked to indicate the frequency in which they engage in those activities. Each question is rated from 0 (Never) to 7 (Every day), for a maximum total score of 98. A higher score represents a higher cognitive engagement level.

In the Luci Physical Activity Questionnaire, participants choose which activities they engage in from a list of almost 70 physical activities. For the selected activities, they are asked to indicate frequency, duration and intensity. Responses are used to calculate the Luci Physical Activity score as well as 3 subscores related to aerobic exercise, muscular resistance, and flexibility training, respectively. A higher score represents a higher physical activity level.

The Luci Medi Diet Adherence Questionnaire consists of 15 questions on consumption frequency for 13 food groups that are considered characteristic of the Mediterranean diet. A subscore ranging from 0 to 3 is assigned to each food group. Total scores range from 0 to 39, where a higher score represents a higher adherence level.

Health care utilisation is assessed using a questionnaire that collects self-reported number of visits to physicians, mental health providers, other providers, emergency department as well as hospital stays, nights in hospital and outpatient surgeries. Total score is the sum of all visits, hospital stays and nights.

Retention rate is the proportion of randomized participants completing at least one of the measures at T3 and T4

Program adherence is defined as the proportion of participants from the Luci condition who adhered to the program. Participants are considered adherent if they complete at least 12 of the 18 coaching sessions.

Pattern of use, frequency, duration of use and functionalities used are continuously monitored throughout the program and the data will be analysed.

User experience is assessed in participants randomized to the Luci intervention using 36 questions of which 29 are rated on a 5-point Likert scale, 3 are rated on categorical scales, and 4 are free text.

Usability is assessed using the System Usability Scale (SUS) a five-item questionnaire rated with a 5-point Likert scale.

Goal attainment and perceived effort to reach the goal are rated by participants in the Luci intervention arm before each coaching sessions. These are reported using 3-point scales.