TY - JOUR AU - Kim, Sun Mi AU - Kim, Da Seul AU - Jang, Yoonsung AU - Kim, Min Kyoon AU - Yu, Eun-Seung AU - Han, Doug Hyun AU - Kim, Hee Jun PY - 2025 DA - 2025/3/26 TI - Evaluating the Effectiveness of a Mobile App for Breast Cancer Self-Management on Self-Efficacy: Nonrandomized Intervention Trial JO - JMIR Mhealth Uhealth SP - e63989 VL - 13 KW - breast cancer KW - mobile health KW - mHealth KW - health education KW - self-efficacy KW - psychological adjustments KW - mobile phone AB - Background: Numerous mobile apps have been developed for patients with cancer. However, there is still no comprehensive app for patients with breast cancer that integrates evidence-based medical information, psychological support, and schedule management through a multidisciplinary medical approach. Objective: We aimed to investigate whether a mobile app designed to assist in the self-management of patients with breast cancer is feasible and positively affects their self-efficacy and other psychological aspects. Methods: The Cancer Manager (CAMA) app was developed to assist in the self-management of patients with breast cancer and survivors of cancer according to cancer trajectory. Its functionalities include providing evidence-based digitalized information created by experts, managing patients’ medication and medical appointment schedules, and providing a delayed question and answer system for patients to query health care professionals. In this nonrandomized intervention trial, we analyzed data from 66 patients with breast cancer, divided into experimental (CAMA: n=34, 52%) and control (treatment as usual: n=32, 48%) groups. Group allocation was determined based on the patient’s willingness to use the app and access to compatible smartphones. Outcome measures included the Korean version of the Cancer Survivor Self-Efficacy Scale, the Korean version of the Mini-Mental Adjustment to Cancer (K-Mini-MAC) Scale, the World Health Organization Quality of Life Brief Version, Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Menopause Emotional Symptoms Questionnaire (MESQ). A user satisfaction survey was also conducted. Results: Throughout the intervention period, the CAMA group (vs treatment as usual group) demonstrated significant improvements in the seeking help and support subscale of the Korean version of the Cancer Survivor Self-Efficacy Scale (F1,64=5.09; P=.03), the psychological well-being subscale of the World Health Organization Quality of Life Brief Version (F1,64=5.48; P=.02), the anxious preoccupation subscale (F1,64=5.49; P=.02) and positive attitude subscale (F1,64=5.44; P=.02) of the K-Mini-MAC Scale, PHQ-9 (F1,64=4.83; P=.03), GAD-7 (F1,64=5.48; P=.02), and MESQ (F1,64=4.30; P=.04). Changes in the anxious preoccupation subscale of the K-Mini-MAC Scale scores were positively correlated with changes in the PHQ-9 (r=0.46; P=.007) and GAD-7 (r=0.41; P=.02) scores and negatively correlated with changes in the positive attitude subscale of the K-Mini-MAC Scale scores (r=–0.36; P=.04). Changes in the PHQ-9 scores were positively correlated with changes in the GAD-7 (r=0.66; P<.001) and MESQ (r=0.35; P=.04) scores. The user satisfaction survey offered insights into the CAMA app’s positive impact; trust-building outcomes; and opportunities for enhancement, such as the inclusion of communication tools and continued content enrichment. Conclusions: The mobile app for breast cancer self-management, CAMA, was deemed feasible and showed promise in improving the patients’ self-efficacy regarding seeking help and support, positive attitude toward cancer, and psychological well-being. In addition, its use might help reduce anxious preoccupation with cancer, depressive mood, anxiety, and menopausal emotional symptoms. Trial Registration: Clinical Research Information Service KCT0007917; https://cris.nih.go.kr/cris/search/detailSearch.do?seq=23348 SN - 2291-5222 UR - https://mhealth.jmir.org/2025/1/e63989 UR - https://doi.org/10.2196/63989 DO - 10.2196/63989 ID - info:doi/10.2196/63989 ER -