Integrating Self-determination Theory and Upper Limb Factors to Predict Physical Activity in Patients With Breast Cancer During Chemotherapy.

BACKGROUND: Some empirical investigations try to describe the factors that affect the physical activity of breast cancer survivors, but these investigations rarely focus on the basic psychological needs or motivation regulation of breast cancer survivors in physical activity. OBJECTIVE: The aim of this study was to construct structural equation modeling of the self-determination theory and upper limb factors to predict the physical activity of breast cancer patients during chemotherapy. METHODS: A total of 236 breast cancer survivors completed measures of basic psychological needs, behavioral regulation in exercise, symptoms and dysfunction of upper limb factors, and physical activity. Path analyses structured the direct and indirect effects (via motivational orientations) of basic psychological needs and upper limb factors on physical activity. RESULTS: A total of 216 (91.5%) participants met the standard physical activity metabolic equivalent recommended. The final model has a good degree of fit (χ2 = 809.363, df = 391, χ2/df ≤ 2.07 [1-3]; root-mean-square error of approximation, 0.067 [<0.008]). The competence (0.309) of basic psychological needs and amotivation (-0.38) of motivation regulations have the greatest effect on physical activity. CONCLUSIONS: Competence is the most important basic psychological need of breast cancer patients during chemotherapy, and amotivation is the most important motivation regulation. IMPLICATIONS FOR PRACTICE: Nurses need to pay more attention to the basic psychological needs and the motivation regulation in breast cancer patients during chemotherapy. Randomized controlled trials of breast cancer survivor interventions based on the self-determination theory are needed.