Psychosocial correlates of physical activity intentions and behaviour in young and middle age adult cancer survivors: An application of an integrated model

Abstract

A theoretical model integrating the Theory of Planned Behaviour (TPB) and the Self-Determination Theory (SDT) was used to examine the influence of autonomous motives on physical activity intentions and behaviours in 104 adult (24-44 years) cancer survivors. Survivors of breast (44%), lymphoma (35%), testicular (15%), and colorectal (6%) cancer completed a mailed survey that included measures of behavioural regulation, TPB, physical activity, medical, and demographic variables. Results showed that survivors who met current physical activity guidelines reported better affective (p=.001), and instrumental attitudes (p=.002), subjective norm (p=.012), perceived control (p=.002), intentions (p<.000), identified regulations (p<.000), and intrinsic motivation (p<.000). Forced entry hierarchical regression analyses demonstrated that the integrated model accounted for 56% of the variance of behavioural intention, with perceived control (ß=.41, p<0.001) and identified regulation (ß=.31,p<0.01) making the only significant unique contributions. Further analysis showed that intention, perceived control, and identified regulation explained 24% of the variance in physical activity behaviour with identified regulation (ß=.40, p<0.001) making the only significant independent contribution. While the TPB has traditionally predominated the physical activity and cancer literature, it appears that interventions that consider and incorporate the principles of SDT may provide a more complete understanding of activity-related behaviour change in young and middle-age adult cancer survivors.

Acknowledgments: I wish to acknowledge Dr. Chris Blanchard for his feedback on the data analyses.