Effectiveness of a Mobile App for Managing Chemotherapy Side Effects and Enhancing Quality of Life in Breast Cancer Patients: A Randomized Controlled Trial

Background Breast cancer patients undergoing chemotherapy often face numerous side effects that reduce their health-related quality of life (HRQoL). While conventional follow-up care is limited in continuity, mobile health (mHealth) interventions, particularly smartphone applications, may offer scalable, real-time support for symptom self-management. Objective This randomized controlled trial (RCT) evaluated the effectiveness of a mobile app designed to manage chemotherapy-related side effects in breast cancer patients. Methods Seventy-two participants receiving chemotherapy at Omid Hospital (Mashhad, Iran) were randomly assigned to an intervention group (app + standard care) or control group (standard care only). The app included 20 modules targeting common chemotherapy-related complications, developed through expert consensus and clinical guidelines. Primary outcomes were changes in HRQoL measured by the EORTC QLQ-C30 and QLQ-BR23 at baseline and after four weeks. App usability was assessed using the System Usability Scale (SUS). Results Fifty-seven participants completed the study (27 in the intervention, 30 in control). The intervention group demonstrated statistically significant improvement in QoL scores compared to controls (p < 0.001), even after adjusting for baseline differences. The app received a SUS score of 73.07%, indicating high usability. The highest user engagement was observed in modules addressing nausea, sleep disturbances, and anxiety. Conclusions The mobile app proved effective in reducing chemotherapy side effects and enhancing QoL among breast cancer patients. Its usability and engagement metrics support further implementation in oncology care, especially in low-resource settings. Trial registration IRCT20230402057801N1 [Registration date 20230512]