S3 File -

Background
This study aimed to establish a structural equation model to determine the associations among knowledge of breast cancer, beliefs about breast self-examination (BSE), BSE practice, socio-economic status (SES), and barriers to BSE among Eastern Chinese women.
Methods
An online cross-sectional correlational survey of 2026 women from Eastern China was undertaken by a self-administered questionnaire in 2020. Structural equation modeling was utilized for examining the interrelationships between BSE barriers and other variables.
Results
Our results suggested that BSE barriers were significantly and negatively related to SES, BSE beliefs, and BSE practices (β = -0.176, p < 0.001 and β = -0.118, p < 0.001 and β = -0.435, p < 0.001, respectively). Among them, participants’ BSE practices had the strongest effects on BSE barriers, while the effect of breast cancer knowledge on BSE barriers was in an opposite direction (β = 0.177, p < 0.001).
Conclusions
BSE barriers were influenced by SES, breast cancer knowledge, BSE beliefs and BSE practices. Our results warn that breast cancer prevention education should strengthen knowledge of practical methods rather than general knowledge. Therefore, intervention strategies designed to develop BSE and breast cancer prevention should take into account multiple factors, in particular finding more effective ways for the public to turn knowledge into a motivator rather than a barrier.