Mexico exhibits a high prevalence of dementia, exceeding 8%, and it is estimated that by 2050 around 3.5 million older adults will be living with this condition. In light of this scenario, it becomes a priority to intervene on the factors associated with the development of dementia through preventive strategies, particularly via multicomponent programs that integrate physical activity, cognitive training, and other components aimed at modifying lifestyles, applied early, before the appearance of clinical symptoms.

In order to expand access to this type of intervention for older adults with limited time or resources for face-to-face care, the implementation of preventive programs remotely through the use of digital media has been proposed. Web platforms constitute an accessible and cost-effective alternative for delivering complex interventions, such as the 'Mind and Movement for Cognitive Health (MeMo-Salud-Cog)' program, designed to promote lifestyles conducive to cognitive health and which has shown promising preliminary results in overall cognitive function, memory, executive function, and attention.

However, the use of digital systems by older adults may be limited by barriers associated with ageing (cognitive, sensory, physical, and motivational), as well as social aspects (education and social isolation) or cultural factors (beliefs and perceived usefulness), which can affect the continuity of their participation. In this context, the present proposal suggests adapting the MeMo-Salud-Cog program to a remote modality, through a website and remote monitoring by healthcare professionals, with the aim of evaluating its feasibility based on usability, satisfaction, effect, and adherence, as well as analyzing perceived acceptability, emphasizng the barriers and benefits of remote intervention.

The investigators will employ a mixed design combining quantitative and qualitative methods, with a pre-post evaluation without a control group in the quantitative part and semi-structured interviews in the qualitative part (pilot study). The study population will consist of independent individuals aged 60 to 75 years affiliated with IMSS at the Family Medicine Unit 1 and 28, with or without cognitive complaints, but without impairment (MMSE ≥ 24), functional independence, at least one vascular risk factor, with a mobile phone or computer, and an informed consent letter.

1. Introduction. In Mexico, dementia represents a significant public health problem due to its high prevalence rates, which continue to grow, especially in rural areas. This situation is linked to a high prevalence of factors associated with the development of dementia, a common characteristic in other middle- and low-income countries, where prevalence and incidence have not decreased as they have in high-income countries. Dementia has significant implications for individuals, their families, and healthcare systems.

   In older people, dementia manifests as memory loss, alterations in thinking, behavioral changes, and difficulties in performing daily activities, which affect their autonomy and independence. The dependence associated with cognitive decline represents a significant economic burden for families, as approximately 80% of total costs are related to ongoing care, a burden that particularly affects informal carers. Furthermore, constant care can have negative effects on the personal, work, and emotional lives of carers, with women bearing the greatest burden, providing nearly 70% of the care hours. In turn, dependence due to cognitive decline significantly increases the demand for and costs of emergency and hospitalization services.

   In this context, various clinical trials have developed multicomponent interventions to reduce dementia-related factors through a multidisciplinary approach. However, the complexity of these programs has led to the integration of digital systems to facilitate their implementation and monitoring.

   Digital media offer an opportunity to improve the effectiveness of health interventions by reducing geographical barriers, expanding accessibility, and promoting ongoing engagement. However, in older adults, their use is limited by cognitive, sensory, physical, and motivational obstacles associated with aging, as well as health complications related to chronic illnesses.

   Cognitive difficulties, such as deterioration in working memory, prospective memory, and procedural memory, along with attention problems and slower processing speed, complicate understanding and efficient use of digital interfaces. Additionally, there are sensory limitations, especially visual ones, and physical restrictions related to motor skills that affect interaction with devices. These barriers can be intensified by motivational factors, particularly when the perceived utility of the technology or its benefits are not evident, potentially leading to frustration and abandonment of interventions.

   Therefore, in health interventions involving digital systems, it is crucial to assess their impact on cognitive function, taking usability and satisfaction into account. This ensures simple interfaces, immediate feedback, and smooth navigation, helping to identify barriers and benefits. In this way, the aim is to offer an effective remote preventive option. It is important to emphasize that quantitative instruments do not always accurately capture participants' expectations, perceived barriers and benefits, or potential strategies for improvement.

   In this context, the program "Mind and Movement for Cognitive Health (MeMo-Health-Cog)" was developed as a multi-component intervention aimed at older adults without dementia in primary care. It combines aerobic physical activity and cognitive training using a grid mat, with the goal of promoting lifestyles that prevent cognitive decline and improve mental health. Preliminary results show improvements in overall cognitive function and a decrease in depression among older adults. In studies still in the process of publication, improvements in memory, executive function, and attention have been observed. Currently, the intervention has been adapted to a web platform to be offered remotely.

   In this pilot study, primary response variables will be measured, such as the impact on subjective, objective, and specific cognitive function, along with adherence. Secondary variables, such as usability and satisfaction, will also be evaluated. Additionally, perceptions of acceptability will be examined, with an emphasis on the barriers and benefits of the remote intervention.

2. The overall objective is to evaluate the effect, usability, satisfaction, barriers, and preliminary benefits of the remote multicomponent intervention supported by a website, over three months, to prevent cognitive decline in older adults from Family Medicine Units No. 1 and 28, with follow-up at three months (t3).

3. The specific objectives are:

   1. To evaluate the preliminary effect of the remote multicomponent intervention supported by a website on the primary response variables (subjective, objective, and specific cognitive function and adherence) in older adults from Family Medicine Unit No. 28, with follow-up at three months (t3).
   2. To evaluate the response of secondary variables: usability and satisfaction with the Mx MAUQ questionnaire of the remote multicomponent intervention supported by a website, in older adults from Family Medicine Unit No. 28, with follow-up at one month (t1) and three months (t3).
   3. To identify secondary qualitative variables (barriers and benefits) of the remote multicomponent intervention supported by a website in older adults from Family Medicine Unit No. 28 at the end of the intervention (t3).

4. Study design: We will employ a mixed quantitative and qualitative design, with pre- and post-evaluation in the quantitative part and semi-structured interviews in the qualitative part (pilot study). This is a trial without phases study that does not require a control group. The study population consists of IMSS beneficiaries affiliated with Family Medicine Units 1 and 28 in Mexico City, Mexico.

5. Hypotheses. a) It is expected that a multi-component remote intervention, supported by a website for three months, will improve subjective, objective, and specific cognitive function in older adults, with effect sizes of 0.20, 0.40, and 0.40, respectively, and an adherence rate of 70% at three months from its start (specific objective). b) It is forecasted that a multi-component remote intervention, with website support, will achieve high satisfaction and usability in older adults at one month and at three months post-implementation (objective 2).

6. Sample size (quantitative part): Considering Viechtbauer's theoretical proposal (10), regarding the minimum sample size for a pilot study of 59 participants and a dropout rate of 20%, the sample size is 71 participants. In the qualitative part, 20 older adults will be interviewed, of whom 10 will be men and 10 women; among the men, 5 will have high adherence to the intervention (≥70%) and 5 will have low adherence (<70%); similarly, for the women, 5 with high adherence and 5 with low adherence will be included. Purposive sampling will be used to identify the barriers and benefits of a multicomponent, remotely delivered intervention delivered via mobile applications and a website. The number of participants in the qualitative stage will be determined based on a systematic review recommendation on sample size for saturation in qualitative research.

7. Development of the website. Through five rounds of brainstorming sessions, the website's content was developed. Six experts helped develop the topics, and a coordinator served as a liaison between the specialists and the systems engineers. An external reviewer from the website development team also participated. All participants in the website's creation were required to have experience with cognitive decline in older adults, either through published articles or completed courses.

   In the first round, the experts used the PICO question to identify the dimensions to be addressed: What aspects would constitute an online motivational educational program for older adults engaging in physical activity? In the second round, after defining the dimensions using the PICO question, the experts requested the subdimensions through the inquiry: What subdimensions would the dimensions of a motivational educational program on a webpage for older adults engage in physical activity have?. In the third round, each expert conducted a systematic review and information search to develop the website's topic. In the fourth round, each topic was presented to the experts, then the investigators offered comments or proposed corrections. Afterward, the liaison coordinator forwarded the questions to the website's programming team and addressed any uncertainties. Finally, the experts re-reviewed the topics and made the final adjustments. In the fifth round, the page is reviewed again with an expert who did not participate in its development, and comments are recorded to make changes.

8. Implementation of the intervention. Individuals who meet the criteria will be offered face-to-face training beforehand on how to carry out the routine and the educational program, both of which are available on the website. The training will last between three and four weeks, depending on learning difficulty, and will be conducted three days a week, with each session lasting one and a half hours. Each group can have up to 10 older adults.

   The training will be facilitated by the support team, consisting of a nurse and a gerontologist, both previously trained. Additionally, participants will be provided with supplementary materials such as a grid mat for cognitive training, a watch to measure heart rate, and a guide brochure for using the website, along with the contact numbers of their instructor to resolve any doubts. Companions or caregivers will receive the same training as the older adults, over three days a week. They will also be instructed on how to assess warning signs and provided with information for emergency care if necessary.

9. Initiation, monitoring, and adherence to the intervention. During the three-month treatment, remote support will be provided through daily morning Zoom sessions. In these sessions, the support instructor will reinforce safety by allowing access only to participants. To do this, all participants will be asked to identify themselves with their reference number and without profile photos; if someone joins with a photo, they will be sent to a waiting room until they provide their number. Zoom activities may be suspended if any participant violates safety rules. If necessary, personalized feedback will be given through messages on WhatsApp, where participants can call or send messages if they have any questions. Participants must complete at least three routines per week to meet the recommendation of 150 minutes of physical activity per week for older adults.

10. Assessments. Assessments will be conducted in person at the start of the study, at one month, and at three months at the National Medical Center Siglo XXI. These will be carried out by trained research personnel with backgrounds in gerontology, nursing, or general medicine. Each assessment will last approximately one and a half hours. The quantitative tests, which include the evaluation of cognitive function using the MMSE, MOCA, Blessed scale, and neuropsychological tests, will be performed at the beginning and end of the intervention. Additionally, the Mx-MAUQ questionnaire will be administered at one month and at the end of the study. Qualitative interviews will be conducted by the principal investigator once the study has concluded. Responses will be recorded in audio; participants' identities will be kept confidential, and they will be assigned a file number.

11. Adverse events The type (e.g., dizziness, pain, fatigue, muscle strains, falls or injuries), number, and severity of adverse events will be recorded during exercise sessions and outside of them throughout the intervention period. The severity of the events will be classified as follows: mild (does not affect daily activities); moderate (has a moderate effect on daily activities); and severe (requires hospitalisation or results in persistent or significant disability, in any medical condition of importance or life-threatening). The study investigators will review all adverse events weekly. They will report all moderate and severe adverse events to the IMSS Ethics Committee and will halt the study if the data from these events indicate any health risk to the older adults.

12. Motivation and adherence strategies To improve adherence and reduce dropouts among older adults in the program, those who do not access the application for a week will receive individual reminder messages via WhatsApp to encourage use of the application and the program's physical exercise component. If an older adult continues not to use the application after another week of WhatsApp messages, a phone call will be made to understand the reasons for not using the application and to try to motivate them to use it. Additionally, for questions, comments, or technical issues, participants can contact by phone or via private message on WhatsApp.

13. Covariables The study covariates will cover Participant demographic and clinical characteristics: age (years from birth); biological sex (male or female); formal educational attainment (years); current employment status (retired, employed, volunteer, unpaid worker, unemployed); marital status (married, widowed, divorced, single, other); and current living situation (living alone, living with a spouse, living with or without children); self-reported comorbidities relevant to this study (e.g., vascular risk factors, orthopedic conditions, etc.).

14. Data Management and confidentiality Data entry will be conducted by trained staff. Data quality will be assessed before statistical analysis (eg, range checks for data values). Only members of the study team will have access to the study information and all information that will be collected from participants will be kept private to ensure confidentiality. The consent forms with participant signatures will be stored in a locked location only accessible by the principal investigator (PI). All electronic data will be stored on the PI laptop and a back-up hard drive which will be password protected. Any handwritten information such as field notes or other related research materials will be stored and secured in a locked cabinet when not in use. Data will be erased and destroyed after 5 years, as per IMSS Ethics and Research Committee guidelines. Only deidentified data will be used for reporting, publication, and dissemination of findings.

15. Statistical analysis Descriptive analysis and handling of missing data

    1. We will perform descriptive analysis of the basic sociodemographic and clinical characteristics of the study groups. Results of the descriptive analysis of continuous variables with normal distribution will be reported with man and standard deviation; variables without normal distribution will be reported as median and interquartile range.
    2. Statistical handling of incomplete data. Firstly, the cleaning and management of missing data in the database will be carried out. Once the cleaning is complete, an original copy will be stored, and another will be used to analyze the data absences, determining the frequency, loss proportion, and pattern of missing data. Additionally, the initial characteristics of the participants who completed the study will be compared with those who were lost, in order to detect possible biases.

    c. Imputation of missing data: if the amount of missing data exceeds 20%, mixed linear models will be used for the main analysis. Missing data will be generated randomly (using at least five methods) and, in more realistic situations, incomplete observations will be included. Finally, a sensitivity analysis will be conducted to verify the stability of the results.

    Primary outcome. To compare the changes over time between the intervention group and the control group, a repeated measures ANOVA with two factors: time and group, will be employed. This analysis will allow evaluation of the effects of time (t0 and t3), the group effect (cognitive function), and the time-group interaction to determine whether the evolution of cognitive function differs between the two groups during the follow-up. In the event that the assumptions of normality are not met, the Friedman test or similar non-parametric methods will be used. When significant global differences are detected, post hoc comparisons with adjustments for multiple testing (covariables) will be conducted to determine the specific differences between the evaluation moments and the groups. The results will be presented with point estimates, 95% confidence intervals, and p-values, with p < 0.05 considered the threshold for statistical significance.

    Secondary outcome. In the analysis of secondary variables, the t1 and t3 values of the Mx-MAUQ score will be obtained. The McNemar's U test will be used to compare the baseline proportions (t0) with those at 1 month (t1) and, subsequently, at the 3-month follow-up (t3). If the distribution of the numerical variables in the study is not normal, as verified by the Shapiro-Wilk test, the medians of the baseline (pre-test) and post-test (t1 and t3) scores will be compared using the Wilcoxon signed-rank test (paired data). A p-value ≤ 0.05 will be considered statistically significant. Additionally, a multivariate analysis will be performed using a generalized linear model to adjust for covariates, with 95% confidence intervals and p-values reported; p < 0.05 will be considered statistically significant. Analysis Will be performed with statistical software STATA 19 and SPSS 27.

    Qualitative Analysis The interviews will be analyzed using an inductive thematic analysis approach. Three researchers with experience in health services and systems research will independently read, code, and analyze the transcripts. Subsequently, decisions regarding emerging themes and the classification of responses will be compared and verified among the researchers to ensure the consistency and reliability of the coding. Discrepancies will be resolved through discussion and consensus. Initially, emerging categories and themes will be identified from the data. Subsequently, the findings will be interpreted in light of the dimensions of the Health Behavior Belief Model, identifying perceptions of change and no change within this conceptual framework.

    The interviews will be conducted using a study guide, and descriptive participant variables will be recorded, including age, sex, education level, and adherence to the intervention. Data management and organization will be performed using ATLAS.ti software.

Inclusion Criteria:

• With and without cognitive complaints (i.e., they have responded 'yes' to the question: 'Do you feel that your memory or learning abilities have worsened recently?").
• They demonstrate independence in activities of daily living and instrumental activities of daily living. • With one or more vascular risk factors (for example, type 2 diabetes or hypertension).
• With a score on the overall cognitive function test of≥ 24 on the Mini-Mental State Examination.
• With a score between 0-4 on the Blessed Dementia Scale.
• With a mobile phone or computer.
• Have a companion, such as a child, spouse, or friend, who can support you during the assessment in case of an emergency.
• Voluntary acceptance to participate in the study through a signed informed consent form prior to your participation.

Exclusion Criteria:

• Depression (score > 15 according to the Epidemiological Studies Center Depression Scale - Revised [CESD-R]).
• With a clinical diagnosis of any significant neurological or psychiatric disorder (for example, Parkinson's disease, schizophrenia).
• With any heart disease.
• Presence of a recent cancer diagnosis.
• History of recent severe cardiovascular event (for example, myocardial infarction, stroke).
• Significant orthopedic conditions (for example, severe osteoarthritis).
• Uncontrolled blood pressure (very high > 180/100 mmHg or very low < 100/60 mmHg).
• Severe visual or hearing impairment.
• Type 2 Diabetes Mellitus requires insulin to control hyperglycemia.

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