Predictive utility of the multi-theory model in physical activity initiation and maintenance intentions among maintenance hemodialysis patients: a cross-sectional study

Background Physical activity (PA) reduces cardiovascular and all-cause mortality in patients undergoing maintenance hemodialysis (MHD); however, PA participation among this population remains suboptimal. As a fourth-generation health behavior theory, the Multi-Theory Model (MTM) uniquely defines independent determinants of behavior initiation and maintenance. However, its applicability in predicting PA behaviors among MHD patients remains unexplored. This study aims to evaluate the predictive validity of MTM constructs for initiating and maintaining PA intentions among MHD patients, providing evidence for developing targeted intervention strategies. Methods A cross-sectional study was conducted from December 2024 to March 2025 at the hemodialysis center of a tertiary hospital in Shandong Province, China. A convenience sample resulted in 274 valid responses. A self-developed questionnaire collected sociodemographic and disease-related data, while the Measuring Change in Physical Activity Questionnaire assessed six MTM constructs. Correlation analysis and hierarchical multiple linear regression explored predictive relationships between MTM constructs and intentions to initiate and maintain PA. Results After controlling for demographic and disease-related covariates, dialogue advantages ( β = 0.238, p < 0.001), dialogue disadvantages ( β = −0.087, p = 0.006), behavioral confidence ( β = 0.560, p < 0.001), and changes in physical environment ( β = 0.180, p < 0.001) from the MTM initiation model significantly predicted PA initiation intention, explaining an additional 56.9% of variance (ΔR 2 = 0.569, p < 0.001). Within the MTM maintenance model, emotional transformation ( β = 0.390, p < 0.001), practice for change ( β = 0.398, p < 0.001), and changes in social environment ( β = 0.131, p = 0.004) significantly predicted PA maintenance intention, accounting for an additional 53.7% of variance (ΔR 2 = 0.537, p < 0.001). Conclusion This study demonstrates the utility of the MTM in predicting PA intentions among MHD patients, particularly in identifying factors related to the initiation and maintenance stages. The MTM framework offers a two-stage perspective on behavior change, contributing to the understanding of key factors associated with PA intentions. Future research could further explore the mechanisms underlying these factors in the broader population of MHD patients.