Effects of Gamified Smartphone Applications on Physical Activity: A Systematic Review and Meta-Analysis

Introduction: This systematic review and meta-analysis aims to examine the impacts of standalone gamified smartphone application-delivered interventions on physical activity. Methods: Web of Science, Scopus, PubMed, PsycINFO, and ACM Digital Library were searched for publications that were published between January 1, 2008 and August 31, 2021. Eligibility criteria were RCTs or single-arm pre-to-post interventions delivered by standalone gamified applications and targeting physical activity. Study-specific results were analyzed using random-effects meta-analysis, with a standardized mean difference. Meta-regressions, subgroup analyses, and sensitivity analyses were performed. PRISMA guidelines were followed, and the Grading of Recommendations Assessment, Development and Evaluation system was used to determine the strength of the evidence. Results: A total of 19 studies with 24 gamified applications were eligible, and 16 studies were included in the meta-analysis. Standalone gamified applications had a small-to-moderate effect on physical activity in both the between-group RCTs (n=12 applications, standardized mean difference=0.34, 95% CI=0.06, 0.62, I²=72%, p<0.01; Grading of Recommendations Assessment, Development and Evaluation: moderate) and the within-group pre-to-post interventions (n=18 applications, standardized mean difference=0.38, 95% CI=0.17, 0.59, I²=74%, p<0.01; Grading of Recommendations Assessment, Development and Evaluation: very low). Leave-one-out sensitivity analyses sustained the main effects with lower heterogeneity (I² of 31.0% and 47.8%, respectively). Discussion: Using gamified smartphone applications as standalone interventions may increase physical activity. Future research could investigate the impacts of gamified applications on physical activity by isolating the role of specific single or clustered groups of application features.