A Culturally Tailored mHealth App (VCheck) to Support Breast Self-Examination Among Thai Women: Development and Formative Evaluation Study.

BACKGROUND: Breast cancer is a leading cause of mortality among Thai women. Breast self-examination (BSE) is a low-cost practice that promotes breast health awareness and familiarity with breast changes; however, adherence and correct technique remain suboptimal, partly due to limited guidance and reminder systems. Mobile health (mHealth) interventions could support BSE practice. OBJECTIVE: This study aimed to develop VCheck, a culturally tailored mHealth app for Thai women, and conduct a formative evaluation of its usability and feasibility. METHODS: A user-centered design framework guided the development of VCheck using the Thunkable cross-platform environment. The app included educational multimedia content, step-by-step BSE guidance, and a smart reminder system. A formative pilot usability study was conducted among 55 female volunteers aged 20 to 50 years over a 2-month period. Usability was assessed using the System Usability Scale. Feasibility and interface design were evaluated using a multidimensional satisfaction questionnaire, and qualitative feedback was collected. RESULTS: The mean System Usability Scale score was 85.4 (SD 6.8), indicating excellent usability. Participants reported high overall satisfaction (mean 4.46, SD 0.68), including with feasibility (mean 4.48, SD 0.64) and interface design (mean 4.44, SD 0.72). Qualitative feedback suggested that the app was easy to navigate and culturally appropriate. CONCLUSIONS: In this formative evaluation, VCheck demonstrated high usability and user acceptance as a culturally tailored mHealth tool for breast health education and BSE awareness among Thai women. The findings support further refinement and larger-scale evaluation of behavioral and implementation outcomes.