The Effect of Periodic Email Prompts on Participant Engagement With a Behavior Change mHealth App: Longitudinal Study

Area of Science:

• Digital health
• Behavioral science
• Public health

Background:

• Mobile health (mHealth) apps are crucial for preventing noncommunicable diseases by promoting lifestyle changes.
• mHealth apps offer accessibility and personalization but struggle with low participant engagement and high attrition.

Purpose of the Study:

• To investigate if periodic email prompts enhance participant engagement with a large-scale mHealth app.
• To analyze how this engagement effect evolves over time using objective measures.

Main Methods:

• Utilized a hidden Markov model (HMM) to analyze data from 22,797 participants over 78 weeks.
• Employed points gained from app activities (workouts, coach interactions) as a measure of engagement.
• Modeled transitions between latent activity states influencing weekly point accumulation.

Main Results:

• On average, 70% of participants remained inactive, 18% were averagely active, and 12% were highly active.
• Receiving and opening a generic email increased the likelihood of activity by 3%.
• Participants responded positively to goal-aligned emails (e.g., health campaigns) but not to promotional ones.

Conclusions:

• Email prompts can positively influence, though modestly, participant engagement in mHealth behavior change apps.
• Given their low cost and mHealth's reach, emails are a cost-effective strategy to improve app effectiveness.
• Targeted, relevant email communication is key to maximizing engagement with digital health interventions.