Table 1 Reporting of adherence to multimodal interventions for preventing cognitive decline

1. Completed studies with published results of adherence

FINGER

(Finland; 2009–2014)

Dietary counseling, exercise and cognitive training, and vascular risk factor monitoring

Simultaneous adherence to all assigned intervention components (CV monitoring, Nutrition, Physical activity, Cognitive training):

- 19.0% were adherent to at least 66% of prescribed treatment

- 38.9% were adherent to at least 50% of prescribed program (i.e., adherent)

- 42% were adherent to less than 50% of prescribed program (i.e., adherent to at least two components; partially adherent)

- 21% were adherent to 0% of the prescribed program (i.e., nonadherent)

[9]

CV monitoring visits:

- 94.6% were adherent to at least 50% of prescribed program

- 92.9% were adherent to at least 66% of prescribed program

Nutrition:

- 90.0% were adherent to at least 50% of prescribed program

Physical activity:

- 60% were adherent to at least 50% of prescribed program

Cognitive training (individual + group sessions):

- 47.2% were adherent to at least 50% of prescribed program

- 24.7% were adherent to at least 66% of prescribed program

[9]

Cognitive training (only individual sessions):

- 63% participated in the cognitive training at least once

- 20% completed at least 50% of the training sessions

- 12% completed 100% of the training

- Mean number of sessions (SD): 45.7 (54.95)

- Median number of sessions: 15 (95%CI 6–23)

[62]

MAPT

(France; 2008–2014)

Integrated cognitive training, physical activity, and dietary advice and preventive consultations plus omega-3 PUFAs

Multidomain sessions:

- 53.5% were adherent to at least 75% of prescribed program

- 64.4% were adherent to at least 66% of prescribed program

Omega-3 capsules:

- 71.5% were adherent to at least 75% of prescribed program

- 76.1% were adherent to at least 66% of prescribed program

Simultaneous adherence to all assigned intervention components (Multidomain sessions and Omega-3 capsules):

- 50.7% were adherent to at least 75% of prescribed program

- 61.1% were adherent to at least 66% of prescribed program

Cardiovascular consultations:

- 90.1% for the baseline visit

- 71.9% for the 1-year visit

- 62.3% for the 2-year visit

Multidomain dose:

- Range: 1–37

- Mean number of sessions (SD): 25.86 (9.26)

[9, 42]

eMIND

(France; 2017–2019)

Web-based multidomain lifestyle training intervention including cognitive training, exercise training, and nutritional advices

Adherence to the MI: Participants accessing all the three interventions (clicking on the multidomain contents in their personal agenda in the web-platform) for at least 75% of the requirements were considered adherent

- 63.8% of participants adhered to the cognitive training

- 60.3% of participants adhered to the nutrition intervention

- 5.2% of participants adhered to the physical exercise intervention

- 5.2% of participants adhered to all multidomain components

- 53.4% of participants followed ≥ 50% of the requested frequency in exercise training (they connected once a week)

- 75.8% of participants followed ≥ 50% of the requested frequency in cognitive training

- 81% of participants followed ≥ 50% of the requested frequency in nutrition

[63]

preDIVA

(The Netherlands; 2006–2013)

Multidomain cardiovascular intervention (advice)

Multidomain dose:

- 22.0% were nonadherent: Participants who on average had received less than 2 out of 3 annual intervention visits (< 66%) upon reaching a study endpoint (dementia/death/end of trial)

[14]

HATICE

(The Netherlands, Finland, France; 2015–2018)

Internet-based platform with remote support from a coach trained in motivational interviewing and lifestyle behavior advice

Login frequency:

- 80% were adhered to the intervention (per-protocol analysis), defined as those who logged onto the platform in at least 12 out of 18 months study participation, and who set at least one goal or entered one or more measurements.

- Reasonable uptake: Median of two logins per month in the platform with a wide range and a substantial proportion logging in more than five times a month), almost all participants setting at least one goal (with a considerable proportion up to three goals), and the majority of participants using the platform during the full study period.

Number of messages exchanged between coach and participant:

- 9.6% of the participants who completed the primary outcome sent 0 messages

- 33.9% sent 1–5 messages

- 29% sent 6–10 messages

- 27.5% sent > 10 messages

Number of goals set:

- Median of 1 goal (IQR 1–2)

- 9.8% set no goal

- 47.3% set 1 goal

- 34.0% set 2–3 goals

- 8.9% set ≥ 4 goals

[26]

MIND-ADmini

(Sweden, France, Germany, Finland; 2017–2020)

Nutritional guidance, exercise, cognitive training, vascular/metabolic risk management and social stimulation

Medical food

Adherence to individual intervention components:

- 71.9% of participants adhered to the cognitive training intervention (attendance to 66% of group and individual sessions).

- 68.8% of participants adhered to the nutrition intervention (attendance to 66% of sessions).

- 81.3% of participants attended both the 3- and 6-month follow-up visits with the study nurse.

- 78.1% of participants adhered to the exercise intervention (attendance to 40% of group-based gym sessions).

- 87.1% of participants consumed ≥ 60% of medical food product (measured through a study product diary).

- 78.1% and 87.1% of participants in the lifestyle and lifestyle + medical food arms were overall adherent, respectively.

Overall adherence to the intervention (composite measure of participation in different intervention components):

- 78.1% of participants in the lifestyle intervention arm attended a minimum of 40% of sessions per domain, in at least 2/4 domains (exercise, nutrition, cognitive training and monitoring of vascular/metabolic risk factors).

- 87.1% of participants in the lifestyle + medical food intervention arm attended a minimum of 40% of sessions per domain, in at least 2/4 domains, and additionally consumed at least 60% of the medical food study product.

Overall adherence to healthy lifestyle changes: composite healthy lifestyle score (ranges 0–8 points) based on the FINGER study(64). A score from 0 to 2 was assigned to each tertile of the healthy dietary intake score, physical activity level, cognitive and social activities, and cardiovascular risk burden

[64, 65]

AgeWell.de

(Germany; 2018–2022)

Nutritional counseling, enhancement of physical and social activity, cognitive training, and the management of cardiovascular risk factors (overweight, smoking).

Adherence to the MI: it was evaluated by asking to what extent participants were able to reach their goals in the domains of nutrition, physical activity, cognitive activity, and social activity (response options: not at all [0]–absolutely [4]). Adherence to all intervention components was summed across all seven points in time, leading to a score ranging from 0 to 28.

Nutrition component (0–4 points):

- Mean adherence (SD): 2.80 (0.71)

Cognitive activity (0–4 points):

- Mean adherence (SD): 2.90 (0.78)

Physical activity (0–4 points):

- Mean adherence (SD): 2.66 (0.82)

Social activity (0–4 points):

- Mean adherence (SD): 2.81 (0.76)

All components (0–28 points):

- Not reported

[25]

GOIZ ZAINDU

(Spain; 2018–2020)

Nutrition counseling, management of vascular risk factors, physical activity, and individual- and group-based cognitive intervention

Overall adherence to the MI:

- 54.7% of participants had high adherence (attendance to all intervention components was higher than 50%)

- 17.2% had partial adherence (attendance to at least 30% of activities of all intervention components)

- 18.8% had low adherence (attendance to any intervention components was lower than 30%)

- 9.4% had very low adherence (attendance to less than 30% to two or more intervention components)

Nutrition component:

- 73.4% completed at least 2/3 nutrition counseling visits

- Mean adherence: 74.5%

CV monitoring component:

- 67.2% completed at least 2/3 cardiovascular monitoring visits

- Mean adherence: 73.44%

Individual cognitive training:

- 64.1% completed > 50% of the cognitive training individual materials

- Mean adherence: 55.47%

Group cognitive training:

- 70.0% attended > 50% of cognition stimulation workshops

- Mean adherence: 54.78%

Physical exercise:

- > 75% of participants reported practicing physical exercise at least twice a week during the intervention period.

Mean adherence: 76.56%

[18]

ASPIS

(Austria; 2010–2014)

Intensive control and motivation for better compliance with prescribed evidence-based medication, regular blood pressure measurements, healthy diet, regular physical activity and cognitive training.

Dietary individual counseling visits (7 in total):

- Median (IQR) attendance: 5 (3–5)

Dietary group counseling visits (7 in total):

- Median (IQR) attendance: 7 (3–7)

Physical activity group meetings (9 in total):

- Median (IQR) attendance: 8 (4–11)

Cognitive group meetings (24 in total):

- Median (IQR) attendance: 12 visits (5.5–17)

[66, 67]

StayFitLonger (Switzerland, Canada, Belgium; 2019–2021)

Computerized physical and cognitive training exercises, plus social interactions through access to a moderated Chat Room, psychoeducational content, and gamification elements.

Mean time weekly spent using the program:

- 2.6 (SD = 0.3) hours

[68]

SMARRT

(USA; 2018–2022)

Multidomain health coaching sessions offered every 4 to 6 weeks

Health contacts:

- Mean (SD): 18.8 (5.5)

- Range: 1–28

[69]

COCOA

(USA; 2018–2022)

Remotely coached multimodal lifestyle intervention

Adherence to the MI:

- 86% of participants remained actively engaged with their coach longer than one year

- 20.7% of participants remained actively engaged with their coach after two years

[70]

Meng X, et al. 2024

(China; 2017–2017)

Online education, cognitive training and community activities

Adherence to online material (number of times that the participants completed the readings):

- Mean adherence: 70%

Adherence to computer-based cognitive training (number of times that the participants completed the trainings):

- Mean adherence: 26.1%

Adherence to face-to-face activities (% of intervention activities attended):

- Mean adherence: 65.2%

[71]

J-MINT (Japan; 2019–2022)

Multicomponent intervention including physical exercise, nutrition counseling and cognitive training

Physical activity

- Mean adherence: 83% (64.9 ± 15.8 out of 78 sessions)

- 84% of participants adhered to ≥ 70% of group-based physical exercise sessions

Cognitive training

- Mean adherence: 44.4% (69.2 ± 96.9 out of 156 sessions)

- 18% of participants adhered to 100% of the cognitive training sessions

[35, 72]

Bae S, et al. 2019

(Japan; 2017–2017)

Multicomponent intervention including physical, cognitive, or social activity sessions

Adherence to the MI:

- 70.2% of participants attended to the MI

[73]

SUPERBRAIN

(South Korea; 2019–2020)

Vascular risk monitoring and management, cognitive training and social activity, physical exercise, nutritional guidance, and motivational enhancement

- Adherence to the MI: 94.5% (95%CI 91.4, 97.6%)

- Vascular and metabolic program: 98.0%

- Cognitive training: 97.4%

- Social activity: 95.9%

- Physical exercise: 91.0%

- Nutrition: 94.2%

- Motivational enhancement program: 97.7%

[74]

SINGER-Pilot

(Singapore; 2018–2020)

Dietary counseling, exercise and cognitive training, and vascular risk factor monitoring

CV monitoring visits:

- 100% of participants completed 100% of the sessions

Home-based exercise:

- 53% of participants completed > 50% of the sessions

Food diary completion:

- 97% of participants filled the food diary in > 50% of their meals for the three required days at each time point

Cognitive training:

- 81% of participants completed > 50% of the training

[75]

Ng PEM, et al. 2021

(Singapore; 2018–2020)

Computerized cognitive training, physical-cognitive dual-task exercises (in small group activities) and nutritional guidance (through mobile app)

Physical-cognitive dual task sessions:

- Mean adherence (SD): 75.78% (19.13)

Small group activities:

- Mean adherence (SD): 78.90% (20.25)

Computerized cognitive training:

- Mean adherence (SD): 70.99% (23.77)

Nutritional mobile application:

Used by 15% of participants

[76]

S-FIT

(Singapore; 2009–2014)

Cognitive training, physical training, and nutritional intervention (dietary supplement)

Adherence to the MI: measured monthly by estimating the proportion of dietary supplements consumed and training sessions completed.

- Mean adherence: 88%

[77]

Ongoing studies within the WW-FINGERS network with prespecified reporting of adherence in the study protocol

LETHE (Austria, Finland, Italy, Sweden)

Nutritional counseling, exercise, cognitive training, management of vascular/metabolic risk factors, social activity, and sleep and relaxation

Individual components:

- Usage of and engagement with the mobile app and smartwatch (frequency and duration of logins).

o During the first 6 months, 50.5% of participants in the intervention group used the full app daily. The median duration of a single session of app usage was 42.1 s in the intervention group. Most participants (98.7%) completed a digital cognitive testing one month after baseline visit.

- Participation in study visits and intervention-related activities and meetings.

Overall adherence to the intervention:

- Adherence to a healthy lifestyle: composite score developed in FINGER, based on self-reported data on exercise, diet, smoking and alcohol, and social and cognitive activity.

[31, 78]

PENSA

(Spain)

Nutritional counseling, physical activity, cognitive training, psychoeducation sessions and social stimulation sessions.

Nutrition counseling visits:

- Mean percentage of sessions (SD): 90.3% (29.6)

- 34.4% were adherent to 100% of sessions

- 80.2% were adherent to 89% of sessions (8 out of 9 visits)

- 99% were adherent to 78% of sessions (7 out of 9 visits)

Gymnasium classes:

- Mean percentage of sessions (SD): 62.1% (38.2)

- 45.8% were adherent to ≥ 75% of sessions

- 70.0% were adherent to ≥ 50% of sessions

Cognitive training:

- Mean percentage of sessions (SD): 72.6% (30.8)

- 60.4% were adherent to ≥ 75% of sessions

- 83.3% were adherent to ≥ 50% of sessions

Psychoeducation sessions:

- Mean percentage of sessions (SD): 79.0% (40.8)

- 75.0% were adherent to ≥ 70% of sessions

Ecological Momentary Assessments (EMAs): average weekly adherence, calculated as the number of days that participants completed the dietary EMAs questionnaire divided by 7 days

- Mean weekly compliance (SD): 89.0% (17.5)

- 93.4% had ≥ 75% of compliance

Fitbit: number of complete observations, defined as at least 600 min of valid minute heart rate signal per day (i.e., wear time indicator)

- Mean monthly valid data (SD): 84.1% (36.6)

- 60.4% had valid data in ≥ 90% of days

- 79.2% had valid data in ≥ 75% of days

- 92.7% had valid data in ≥ 50% of days

Epigallocatechin-3-gallate (EGCG): presence of ≥ 10 ng/mL of EGCG in plasma

- 93.5% of compliance at 6 months

- 85.1% of compliance at 12 months

[32]

(unpublished data)

MET-FINGER

(UK, Finland, Sweden)

1. Dietary counseling, exercise and cognitive training, and vascular and metabolic risk factor monitoring

2. Metformin when appropriate

Individual components:

- Cognitive training: attendance at the cognitive training sessions including automatic recordings of computer program use, and group sessions attendance.

- Nutrition: attendance at the 7 group and 3 individual nutrition sessions.

- Vascular and metabolic risk factors monitoring: attendance to 6 individual consultations (at least 3 with a study physician).

- Physical exercise: participation in group exercise sessions.

- Metformin: adherence to target dose and compliance to treatment.

Overall adherence to the intervention: calculated through composite measure of participation in different intervention components.

[36]

LatAM-FINGERS (Argentina, Brazil, Bolivia, Chile, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, Mexico, Paraguay, Peru, Puerto Rico, and Uruguay)

Exercise, diet, cognitive/social stimulation, and cardiovascular health

Implementation: level of fidelity to the intervention protocol estimated on the basis of:

- % attendance to team meetings

- % physical activity sessions completed

- % cognitive training sessions completed

- % telephone contacts completed

- % health monitoring visits completed

- Participant’s self-reported adherence to the intervention

[30]

Africa-FINGERS

(Kenya and Nigeria)

Exercise, diet, cognitive/social stimulation, and cardiovascular health

Intervention compliance/adherence will be measured via attendance records at group intervention meetings (e.g., for physical, social, and cognitive activities), questionnaires on dietary changes/intake, subjective reports of satisfaction with progress to monitor skills/brain training, and regular vascular and metabolic risk monitoring (blood pressure, body mass index, and blood work).

[33]