Abstract
BACKGROUND: Delays in seeking care after noticing breast cancer-related symptoms are common and may impair outcomes and health-related quality of life. Existing patient-reported measures often emphasize symptom awareness or general help-seeking attitudes and do not capture capability across the full help-seeking process. This study aimed to develop and preliminarily validate a multidimensional scale of breast cancer symptom help-seeking capability. METHODS: We conducted a cross-sectional instrument development and validation study in a tertiary hospital in Zhejiang, China, and collected data from 1 February 2025 to 30 June 2025. Items were generated under a theory-informed blueprint and reviewed by experts to form a 16-item pilot. We evaluated the scale’s structure and item performance using modern measurement modeling, and examined reliability and construct validity through theory-guided correlations and regression analyses. We assessed symptom help-seeking capability across four domains: Awareness, Knowledge, Action, and Support. RESULTS: N = 198. Five response categories were well used; category probability curves were ordered and step thresholds largely increasing. Two items (B2, D1) showed comparatively weaker performance; their removal produced a 14-item operational form with improved reliability (overall α from 0.943 to 0.948; Knowledge α from 0.769 to 0.795; Support α from 0.780 to 0.818). Domain correlations were strong and directionally consistent: Awareness-Knowledge r = 0.778; Knowledge-Action r = 0.803; Support with Awareness/Knowledge/Action r = 0.777/0.774/0.809 (all p < 0.001). In regressions, Knowledge was positively associated with Awareness and Support (R² = 0.677), and Action with Knowledge and Support (R² = 0.733); model diagnostics did not suggest major violations. CONCLUSION: The BCSHC is a concise, theory-informed instrument for assessing symptom help-seeking capacity among patients with breast cancer, and the recommended form contains 14 items with initial evidence supporting reliability and construct validity. It may help identify stage-specific barriers and inform targeted supportive interventions; further studies should confirm stability and responsiveness in diverse samples. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12955-026-02474-3.