Walking And Thriving for Community Health (WATCH) study: Can digital health prompts boost daily physical activity in adults?

A three-arm randomised controlled trial will be conducted using digital health technologies, a mobile application and a smartwatch—in a free-living environment. The trial will target members of St. Lukes Health insurance, aiming to evaluate the effectiveness of behavioural change prompts in promoting sustained increases in daily walking. Participants, aged 18 to 74 years, will use the Snug Health app synced with a Garmin smartwatch to track and monitor their daily movement. Two experimental groups (synergy and single BCT group) will receive daily prompts delivered through the digital health-system based on their previous 60-minute inactivity status, whereas the control group will not receive any prompts to engage in daily movement habits. If there is no activity detected for the past 60 minutes, an automatic prompt will be sent to participants’ smartwatch through the Snug Health app in both experimental groups. The smartwatch will track inactivity status and upload this information to the cloud server, which will then relay it to the Snug Health app. Based on the participant’s assigned group, the Snug Health app will generate a prompt, send it back to the cloud server, and finally deliver it to the participant’s smartwatch as a reminder. Control participants will only receive notifications at the end of each day to charge their watch and to wear it for > 8 hours/day. Participants will wear their smart watch for 12 weeks that will include a 6-week intervention period. We will objectively track the primary outcome variable (participant weekly step counts) throughout the study. These data will be analysed through 15-minute epochs of wear time. For the synergy group five synergistic behaviour change techniques will be delivered to the participants’ smartwatch across a sequential five-day pattern. The sequence will start on Monday with goal setting, action planning (Tuesday), self-monitoring (Wednesday), information about health consequences (Thursday) and end on Friday with self-talk. For example, the synergy group will receive a goal setting prompt on Monday to ‘Set a weekly step goal’. This goal will be recorded in the Snug Health app and used as a benchmark for progress through the rest of the week. Each prompt will target a different phase of behaviour change based on the Health Action Process Approach (HAPA) model (Bohlen et al., 2020). This model initiates risk perception at the motivational phase leading to the formation of an intention (the decision to start exercising). We selected BCTs to enhance participant motivation such as ‘goal setting’ and 'information about health consequences', and to translate intention into action (taking steps) such as ‘action planning’ and ‘self-talk’. This synergistic approach reflects a shared implicit understanding of an additive relationship between intervention techniques and their combined effectiveness to elicit behaviour change, as demonstrated by previous studies (Parkinson et al., 2023; Schwarzer, 2016). The single BCT group will also have their steps tracked through the digital health system, and if there has been no activity (steps) for the last 60 minutes a single prompt (Be active! It is time to move) will be delivered. This single prompt will be delivered throughout the intervention period so we can test the effectiveness of the synergy group strategy. Adherence to the wearing the smartwatch will be initially monitored daily during the three-week onboarding phase. Participants who fail to wear their smartwatch for at least 8 hours per day most days per week during this phase will be reminded of this requirement through the Snug Health app and if the behaviour persists will be excluded before the intervention phase begins. Adherence to the intervention will be measured weekly by monitoring the 15-minute epoch steps data produced by the smartwatch. This study is designed to assess the impact of these digital health interventions on walking behaviour over time, offering valuable insights into the effectiveness of digital health tools in promoting physical activity among health insured members in real-world settings. The findings will contribute to the broader understanding of how digital health interventions can support long-term behavioural change and inform future health promotion strategies.