Evaluating the influence of persuasive systems design on continuance intention, perceived effectiveness, and weight loss

Background Digital health interventions for behavior change show great promise in supporting patients who need to self-manage or prevent chronic diseases. Persuasive features are crucial to the continued use of behavior change support interventions, though less is known about how users’ perceptions of these features shape evaluations of technology acceptance and health outcomes. Objective This study examined how perceived persuasive design principles influence perceived persuasiveness and technology acceptance factors (perceived effort, continuance intention, perceived effectiveness) in a mobile digital health intervention to support weight management. Methods The study is a secondary analysis of a subset of the data (n=181) from a randomized controlled trial of users of a weight-focused mobile application. Data were analyzed using PLS-SEM to test the proposed model and examine the relationships among the study variables. Results Our findings showed that persuasive design features of the primary task, dialogue support, credibility support, and postulates of unobtrusiveness and transparency explained 65.6% of the variance in perceived persuasiveness. In turn, perceived persuasiveness influenced perceived effort, continuance intention, and perceived effectiveness. The model explained 12.7% of the variance in weight change, with medium predictive power. Moreover, introducing age as a moderator between perceived effectiveness and weight change increased the model’s explanatory power (from R 2 =12.7% to 16.3%). Conclusion The findings contribute to the theoretical understanding of persuasive systems design and technology adoption in digital health interventions, offering insights for researchers and designers on how these principles can support health behavior change.