Moderating Role of Condom-Use Inertia on the Association Between Status Quo Bias and Pre-Exposure Prophylaxis Resistance Intention Among Chinese Men Who Have Sex With Men: Cross-Sectional Study.

Background: While prior studies have examined structural and individual-level barriers to pre-exposure prophylaxis (PrEP) uptake, little is known about the psychological mechanisms underlying resistance to PrEP, particularly among high-risk groups. The status quo bias (SQB) theory provides a theoretical framework for understanding why individuals may resist beneficial health innovations. Objective: The aim of this study was to examine the associations between SQB and PrEP resistance intention among Chinese men who have sex with men (MSM) and to test whether condom-use inertia moderated these relationships. Methods: We conducted a cross-sectional online survey among 1022 MSM in China from November 2024 to February 2025. Theory-guided multi-item measures were constructed to capture key dimensions of SQB. Their internal consistency and construct validity were examined using confirmatory factor analysis prior to regression modeling. Multiple linear regression models assessed main effects and moderation effects, adjusting for sociodemographic and behavioral covariates. Results: A total of 1022 MSM were included in the final analysis (mean age 29.6 y); the majority identified as homosexual (767/1022, 75.1%) and were unmarried (896/1022, 87.7%). Regression analyses revealed that transition costs were positively associated with PrEP resistance intention (β=0.26, 95% CI 0.17-0.35; P<.001), while social norms were negatively associated (β=-0.19, 95% CI -0.27 to -0.12; P<.001). Condom-use inertia significantly moderated both associations, amplifying the positive relationship between transition costs and resistance (β=0.04, 95% CI 0.01-0.09; P=.03) and enhancing the negative association of social norms (β=-0.05, 95% CI -0.09 to 0.00; P=.04). Subgroup analyses showed that the amplifying effect of condom-use inertia on transition costs was particularly evident among participants with postgraduate education (β=0.13, 95% CI 0.01-0.26; P=.04). Conversely, its strengthening effect on social norms was more pronounced among MSM 30 years or younger (β=-0.11, 95% CI -0.17 to -0.04; P=.001) and those identifying as homosexual (β=-0.07, 95% CI -0.12 to -0.02; P=.01). Conclusions: This study suggests that SQB is an important psychological barrier to PrEP adoption among Chinese MSM. The moderating role of condom-use inertia highlights the relevance of habitual condom-use routines in shaping PrEP resistance. Behaviorally informed strategies that reduce transition costs and leverage social norms may help mitigate resistance and improve PrEP uptake.