Effectiveness of NeoMayor in Improving Cardiovascular Health in Chilean Older Adults

Population aging in low- and middle-income countries has led to an increasing burden of non-communicable diseases, particularly cardiovascular disease and dementia. A substantial proportion of cardiovascular and dementia risk factors are modifiable, making lifestyle-based preventive interventions a public health priority.

Multidomain interventions targeting physical activity, diet, sleep, and psychosocial factors have demonstrated effectiveness in reducing cardiovascular risk and supporting cognitive health. However, implementation barriers such as limited access, low adherence, and healthcare inequities reduce their impact in real-world settings.

Mobile health interventions offer a scalable alternative, particularly in settings with increasing smartphone adoption among older adults. NeoMayor was developed using a user-centered design approach and demonstrated feasibility and potential effectiveness in a pilot study of 2 months conducted in Chile. That pilot did not assess sustained use beyond the initial period, so no prior data exist on how engagement or adherence evolve over a four-month intervention.

This trial follows a Hybrid Type 1 design, the primary aim is confirmatory and evaluates clinical effectiveness on cardiovascular health index; the implementation aim is exploratory and evaluates strategies to support sustained engagement. This distinction is reflected in the statistical analysis plan, where only the primary effectiveness outcome is powered for confirmatory testing.

The implementation aim is guided by the RE-AIM framework, focusing on reach, adoption, fidelity, and maintenance. Within the NeoMayor arm, participants are randomized to receive the app with or without a human health coach, and with or without a wearable device. These two implementation support strategies are evaluated through their main effects on engagement, adherence, retention, and maintenance of app use, using the full intervention arm sample. The coach x wearable interaction, and any association between implementation outcomes and clinical outcomes, will be analyzed descriptively and reported as exploratory, given the sample size was not calculated for these comparisons.

Inclusion criteria

• Age between 55 and 75 years
• Able to read and understand written instructions
• Ownership of a smartphone and ability to use it independently
• Physically inactive, defined as performing less than 30 minutes of daily physical activity or less than 2,5 h a week.
• Intermediate or high cardiovascular risk, defined as the presence of at least three of the following: Hypertension (history diagnosed by specialist or general practitioner or ≥ 140 mmHg systolic or ≥90 mm Hg diastolic blood pressure at baseline or current antihypertensive treatment);Diabetes Mellitus (history diagnosed by specialist or general practitioner or fasting blood glucose ≥126 mg/dL or current pharmacologic treatment);Obesity (BMI ≥30 kg/m²); Dyslipidaemia (history diagnosed by specialist or general practitioner or lipid-lowering drugs or baseline total cholesterol ≥ 200 mg/dL or LDL cholesterol ≥100 mg/dL).

Exclusion criteria

• Dementia defined as a score in the MEFO < 9
• Significant limitations for independent mobility, including use of assistive devices, frailty, gait instability, or lower-limb painful conditions limiting physical activity
• Uncorrected hearing or visual impairment preventing adequate use of a smartphone
• Chronic neurological, psychiatric, or psychological disorders without regular treatment or follow-up.
• Present severe alcohol or illicit drug use.
• Severe or terminal illness