Applied theory of planned behavior to explore associated factor of physical activity level among Chinese childhood cancer survivors.

Objective: Low physical activity (PA) levels are common among childhood cancer survivors (CCS) and have a serious negative impact on their physical recovery and long-term health. This study aimed to explore the factors that contribute to low levels of PA from the perspective of children themselves and how these factors affect their PA.

Methods: In this cross-sectional survey, CCS were recruited by purposive sampling from several children's medical centers nationwide. The online questionnaires, which involved three valid scales (the Godin Leisure-Time Exercise Questionnaire, Theory of Planned Behavior (TPB) construct, and Physical Activity Self-efficacy), were used for data collection from July 2021 to January 2023. The Wilcoxon rank-sum test, Chi-square or Fisher's exact test, and logistic regression analysis were used to analyze the factors associated with PA in CCS. The associations between CCS' PA level and cognitive variables (TPB construct and self-efficacy) were evaluated using path analysis.

Results: Among the 1350 eligible participants, ultimately 964 of them submitted valid questionnaires. According to the leisure time index (LSI) scores, 59.34% of Chinese CCS reached the recommendation level of moderate-vigorous physical activity (MVPA) (LSI ≥ 24). Attending school, diagnosis, time since discharge, behavioral intention, and self-efficacy were associated with MVPA levels in CCS. Path analysis showed that intention and self-efficacy exerted a direct effect on CCS' PA, whereas the direct impact of perceived behavioral control on MVPA was not significant. The overall model fit indices of the TPB extended model incorporating self-efficacy showed the model fits the data well (RMSEA = 0.000, CFI = 1.000, NFI = 1.001, and TLI = 1.009).

Conclusion: Compared to healthy populations, the level of MVPA participation among Chinese CCS was relatively lower. Improving self-efficacy is essential for increasing participation in CCS' physical activities. The extended TPB model with self-efficacy is appropriate for explaining MVPA participation in CCS.

Implications For Cancer Survivors: This study highlights the critical need to address low physical activity levels among childhood cancer survivors (CCS), as insufficient engagement in moderate-vigorous physical activity (MVPA) may hinder their recovery and longterm health outcomes. The findings underscore the pivotal role of self-efficacy in promoting MVPA participation, with both direct and indirect effects on activity behaviors. Interventions targeting CCS should prioritize strategies to enhance self-efficacy-such as goal-setting, skill-building, and psychosocial support-to foster sustained engagement in physical activity. Additionally, the validated extended theory of planned behavior (TPB) model provides a framework for designing tailored, survivor-centered programs that address behavioral, social, and environmental barriers. Clinicians and caregivers should adopt multidimensional approaches integrating self-efficacy enhancement, peer/community support, and accessible physical activity opportunities to mitigate long-term health risks and improve quality of life for CCS.