Psychosocial factors influencing HPV vaccination intention among male college students in Hangzhou city: A cross-sectional study based on an extended theory of planned behavior model.

Human papillomavirus (HPV) vaccination for males is critical for reducing the global burden of HPV-related diseases. This study utilized an extended Theory of Planned Behavior (TPB) framework to identify determinants of vaccination intentions among Chinese male undergraduate students. A cross-sectional study was conducted between March and May 2025 in Hangzhou, China, recruiting 1,310 participants via multi-stage stratified cluster sampling. The dependent variable was vaccination intention. Independent variables included sociodemographics, TPB constructs (behavior attitude [BA], subjective norms [SN], and perceived behavioral control [PBC]), HPV knowledge and risk perception. We employed a three-step hierarchical linear model (Model 1: sociodemographics; Model 2: adding TPB constructs; Model 3: adding HPV knowledge/risk) and structural equation modeling (SEM) to test latent paths. Among the 1,310 participants (balanced across four academic years), 62.7% expressed a willingness to receive the HPV vaccine. Hierarchical regression revealed that sociodemographics explained 2.1% of the variance in vaccination intention (Model 1), which increased to 25.1% with the inclusion of TPB constructs (Model 2), and reached 32.7% in the final model (Model 3) (F = 126.245, p < .001). SEM analysis further validated the model (χ2/df = 2.102, RMSEA = 0.068, GFI = 0.968), accounting for 75.9% of the total variance in behavioral intention. PBC was identified as the most powerful predictor (β = 0.527, p < .001), followed by BA, SN and HPV-related knowledge. Additionally, higher self-assessed risk of infection significantly predicted stronger intentions. The results of this study indicated that increasing vaccination rates requires policy interventions to improve vaccine accessibility and affordability, alongside fostering positive attitudes and social support through targeted health education.