for people ages 18-75 (full criteria)
healthy people welcome
study started
estimated completion



The aim of this research is to evaluate the efficacy of contextually tailored activity suggestions and activity planning for increasing physical activity among sedentary adults.

Official Title

Heart Steps: Adaptive mHealth Intervention for Physical-Activity Maintenance


This project file refers to Aim 2 and Aim 3 of the National Heart, Lung, and Blood Institute (NHLBI) grant. Aim 1 is registered in clinical under a separate project file number, NCT03225521.

Many of the risk factors for heart disease are behavioral, such as physical inactivity, smoking, and diets high in saturated and trans-fats. Prevention programs are effective at helping patients make the initial lifestyle changes needed to reduce their risks, but patients often struggle to maintain those changes.

In this study the investigators propose to develop a novel mHealth application for supporting maintenance of physical activity. Kaiser Permanente Washington Health Research Institute (KPWHRI) will conduct a prospective study to test the application among Kaiser Permanente Washington (KPW) men and women with blood pressure that falls in the stage 1 hypertension range. By taking advantage of the frequent interactions that individuals have with their mobile phones throughout the day, the investigators will design and evaluate an adaptive, personalized application that (1) keeps patients reminded of their health goals and motivations; (2) provides actionable ideas for how patients can be active right now, given their current context; and (3) helps patients plan and reflect on their physical activity to enable creation of robust and sustainable physical-activity habits. In addition, the application will adapt its functioning for each patient over time in order to minimize user burden while optimizing its ability to encourage physical activity and maintain engagement with the intervention.

Through three Specific Aims—intervention development, intervention optimization, and pilot evaluation—this project will contribute: (1) understanding of how burden and intervention engagement change over time and how they are influenced by intervention delivery and patients' behavior and context; (2) generalization of learning algorithms that are used to personalize web content based on users' characteristics and past behavior for use in mHealth interventions for behavioral maintenance; and (3) new insights about how reflective and automated self-regulatory processes interact over time to support behavioral maintenance and how to optimally recruit these processes through an mHealth intervention.

Aim 2: Optimize intervention and investigate influences on participant response.

The investigators will conduct a three-month micro-randomized pilot study within-subject field study with 40-50 participants with blood pressure readings that fall in the stage 1 hypertension range. Goals for this aim include (1) perform in-situ usability and user-experience testing of the intervention; (2) finalize and tune the intervention's learning algorithms; (3) develop initial decision rules for when and for whom individual intervention components will be provided; and (4) begin to investigate how participants' physical activity, burden, and patterns of engagement with the intervention are affected by different intervention features and the context of use.

Aim 3: Pilot the personalized just-in-time adaptive mHealth intervention over 9 months The investigators will conduct a 9 month-long single-arm pilot study of adaptive mHealth intervention for physical-activity maintenance with 50-60 participants with blood pressure readings that falls in the stage 1 hypertension range. The investigators will (1) evaluate the feasibility and acceptability of the intervention for use over the course of nine months; (2) assess the ability of the learning algorithms to personalize intervention delivery over time; and (3) investigate how cardiac patients' responses to the intervention—physical activity, burden, and engagement—change over time as functions of time-varying application use and time-varying contextual factors. The study will also enable the investigators to gather empirical evidence to plan a follow-up RCT to test the efficacy of the intervention. Development of effective mHealth interventions requires advancements in and collaboration between computer science, human-computer interaction, and behavioral and health sciences. This project makes contributions to all three disciplines and deepens understanding of how to design personalized, adaptive interventions that help individuals not only to adopt but also sustain health-promoting behavior changes over the long-term.

Aim 2 and Aim 3 activities will take place sequentially. The recruitment and participant experience will be almost identical. Differences beyond scientific objectives between the Aim 2 and Aim 3 groups is the time each group is enrolled in the testing trial. Slight modifications are made to materials due to the difference in enrollment time.

No hypotheses will be tested. The purpose of both studies is to develop and test for usability and acceptability of an mHealth application that supports maintenance of physical activity of patients with high blood pressure.


Physical Activity Mobile Health Self Monitoring Wearable Sensors Tailored Health Communication Implementation Intentions Mobile Apps Anti-Sedentary Behavior Opportunistic Physical Activity Health Belief Model HeartSteps: A just-in-time intervention for increasing physical activity among sedentary adults.


You can join if…

Open to people ages 18-75

  • English speaking
  • Recent blood pressure readings that falls in the stage 1 hypertension range by new AHA/ACC guidelines [>= 130 systolic]
  • Owns an iPhone
  • Able to walk for 10 minutes without pain
  • Expresses desire during study screen to increase physical activity

You CAN'T join if...

  • Taking hypertension meds
  • Any diagnosis where physical activity would be counterindicated
  • Recent acute cardio vascular event
  • Major psychiatric illness


not yet accepting patients
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