A prospective study of the determinants of exercise in bladder cancer survivors using the Theory of Planned Behavior

Although exercise has gained recognition as an effective supportive care intervention for cancer survivors, exercise participation rates are low. The present study examined the determinants of exercise in bladder cancer survivors using the Theory of Planned Behavior (TPB). Bladder cancer survivors (N = 397) residing in Alberta, Canada completed a mailed questionnaire at baseline that assessed demographic, medical, behavioral, and social cognitive variables and a second questionnaire 3 months later that assessed exercise. Multiple regression was the primary analysis. Adjuvant therapy (r = -0.10, p = 0.021), cancer invasiveness (r = -0.10, p = 0.051), and age (r = -0.11, p = 0.037) were all negatively associated with exercise. Intention (beta = 0.25, p < 0.001), perceived behavioral control (beta = 0.18, p = 0.001), and planning (beta = 0.12, p = 0.018) explained 20.9% of the variance in exercise over a 3-month period. Perceived behavioral control (beta = 0.32, p < 0.001), affective attitude (beta = 0.18, p = 0.002), instrumental attitude (beta = 0.15, p = 0.025) and descriptive norm (beta = 0.10, p = 0.032) explained 39.1% of the variability in exercise intention. Constructs from the TPB mediated the associations between adjuvant therapy, cancer invasiveness, age, and exercise. Age and adjuvant therapy also moderated some of the associations within the TPB. Some medical and demographic variables predict exercise behavior in bladder cancer survivors, but these associations are mediated by the TPB. Interventions based on the TPB may be effective for promoting exercise in this cancer survivor population.