Abstract
BACKGROUND: Survivors of breast cancer often face challenges in maintaining physical activity (PA) and reducing sedentary behavior (SB), which are crucial for recovery and long-term health. Digital behavior change interventions (DBCIs) have emerged as promising tools to address these behavioral targets. OBJECTIVE: This systematic review and meta-analysis aimed to assess the effectiveness of DBCIs in promoting PA and reducing SB among survivors of breast cancer. METHODS: A comprehensive search of 10 databases-PubMed, Embase, PsycINFO, the Cochrane Library, CINAHL, Web of Science, the China National Knowledge Infrastructure database, the Wanfang database, the VIP database, and the Sedentary Behavior Research Database-was conducted to identify eligible randomized controlled trials that investigated the effectiveness of DBCIs in promoting PA and reducing SB among survivors of breast cancer. Study quality was assessed using the Cochrane Risk-of-Bias tool. Data synthesis was conducted via Review Manager. Owing to anticipated heterogeneity, a random-effects meta-analysis was used. The evidence quality was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation approach. RESULTS: A total of 29 randomized controlled trials involving 2229 participants met the inclusion criteria. Most DBCIs were delivered at the interpersonal level using common behavior change techniques, including social support (unspecified), instruction on how to perform the behavior, demonstration of the behavior, action planning, and problem-solving. Meta-analysis revealed that DBCIs significantly improved shoulder range of motion across all planes (flexion: standardized mean difference [SMD]=2.08, 95% CI 1.14-3.01; P<.001; extension: SMD=1.74, 95% CI 0.79-2.70; P<.001; abduction: SMD=2.32, 95% CI 1.35-3.28; P<.001; external rotation: SMD=2.29, 95% CI 0.96-3.62; P<.001; internal rotation: SMD=2.98, 95% CI 1.08-4.87; P=.002; adduction: SMD=2.09, 95% CI 1.16-3.02; P<.001), finger climbing wall height (SMD=1.65, 95% CI 1.35-1.95; P<.001), upper-extremity function (SMD=-0.96, 95% CI -1.50 to -0.42; P<.001), quality of life (SMD=1.83, 95% CI 0.44-3.22; P=.01), and reduced pain (SMD=-0.58, 95% CI -0.93 to -0.22; P=.002). However, no significant differences were found in steps (P=.69), time spent in light PA (P=.51), time spent in moderate to vigorous PA (P=.43), sedentary time (P=.18), or physical function (P=.71 or .11). CONCLUSIONS: DBCIs effectively improve upper-body mobility, function, quality of life, and pain management in survivors of breast cancer. Future research should explore multilevel DBCIs specifically designed to address whole-body PA and SB reduction, with effectiveness evaluated through methodologically rigorous, large-scale trials. TRIAL REGISTRATION: PROSPERO CRD42023448098; https://www.crd.york.ac.uk/PROSPERO/view/CRD42023448098.