Trust buffers price-related barriers to HPV vaccination among female college students: a cross-sectional study in China based on the 3C model

Purpose HPV vaccine hesitancy is prevalent among female college students in China, yet how trust interacts with cost concerns remains unclear. This study, grounded in the 3C model, examined whether trust in healthcare professionals buffers price-related barriers and identified high-risk subgroups. Methods A cross-sectional survey recruited 4,326 female college students from 12 Chinese provinces. Trust, price perception, and vaccination intention were measured. Interaction effects were tested using the Breslow-Day test; a decision tree model (CART) identified high-risk profiles. Results Trust in healthcare professionals showed the strongest positive correlation with vaccination intention ( r s = 0.610, p < 0.001), with a clear dose–response pattern. A significant trust-by-price interaction emerged ( p = 0.008): among low-trust respondents, high price was associated with substantially higher hesitancy (78.5% vs. 54.3%, p < 0.001); among high-trust respondents, the price effect was negligible (35.6% vs. 30.1%, p = 0.12). The most frequently cited reasons for hesitancy were high cost (53.5%), fear of side effects (52.7%), and limited vaccine knowledge (46.3%). Decision tree analysis identified “low trust and high price” as the dominant high-risk profile, accounting for 32.4% of all hesitant individuals. Conclusion Trust can buffer price-related barriers to HPV vaccination. Stratified interventions should prioritize the “low trust and high price” group through combined trust-building and financial support.