Physical and Psychological Effects of Smartphone App-Based Walking Interventions in Community-Dwelling Older Adults: Systematic Review and Behavior Change Technique-Informed Analysis.

Background: With the global increase in population aging, promoting walking as a health behavior to maintain and enhance well-being among older adults has become increasingly important. In recent years, advances in information and communication technology and mobile health have supported the development of health interventions delivered through smartphone apps. However, no review to date has included psychological aspects such as motivation or intention to walk, and the behavior change techniques (BCTs) embedded in smartphone apps that effectively promote walking remain unclear. Objective: This study had 2 primary aims: (1) to evaluate the effects of smartphone app use on walking behavior and intention to walk among community-dwelling older adults and (2) to identify the specific BCTs delivered through these apps that may promote walking behavior and intention effectively. Methods: Eligible studies were those published in English or Japanese between March 1, 2015, and February 28, 2025, that focused on community-dwelling older adults, implemented smartphone app-based interventions, and reported walking-related outcomes. A systematic search strategy was designed using keywords such as "older," "smartphone," and "walking." Risk of bias was evaluated using the Study Quality Assessment Tools. The features of the apps described in the selected studies were examined to identify the BCTs they used, as categorized by the BCT Taxonomy. Results: Of the 296 studies initially retrieved, 8 met the inclusion criteria. These studies varied in terms of participant characteristics, intervention duration, app features, and outcomes, and most were pilot studies. While several apps were designed specifically to increase walking, others included features that facilitated social interaction among users. In addition, 2 studies also reported improved motivation to walk. Apps that were associated with statistically significant improvements in walking behavior frequently used BCTs from the following clusters: (1) goals and planning, (2) feedback and monitoring, and (4) shaping knowledge. Notably, 5 BCTs were not incorporated into any of the reviewed apps. Conclusions: Although smartphone apps have the potential to improve walking behavior and intention among community-dwelling older adults, the current body of evidence remains limited. Apps that deliver walking-related knowledge, facilitate goal setting, and support behavioral monitoring appear especially effective and may strengthen walking behavior and intention in this population.