Physical Activity and Social Cognitive Theory: A Test in a Population Sample of Adults with Type 1 or Type 2 Diabetes

The purpose of the study was to test the Social Cognitive Theory (SCT; Bandura, 2004 ) for explaining physical activity (PA) in a large population sample of adults with type 1 or type 2 diabetes. Study objectives: (1) test the fit of the SCT structure in the total sample, and the diabetes sub-types; (2) determine the SCT structural invariance between the type 1 and type 2 groups; and (3) report explained variance and compare strength of association for the SCT constructs in predicting PA for both type 1 and type 2 groups. In all, 2,311 individuals with type 1 or type 2 diabetes were assessed on their self-efficacy, outcome expectancies, impediments, social support, goals, and physical activity at baseline and 1,717 (74.5%) completed these assessments again at 6 months. Multi-group Structural Equation Modeling was conducted. The findings provide evidence for the utility of the SCT in the diabetes samples. The SCT fits individuals with type 1 and type 2 diabetes except for SCT impediments, which appear to be obstructing goal-setting in individuals with type 2 diabetes only. Promotion of health behavior should target self-efficacy to set goals and change behavior. Outcome expectancies and social support are also important factors for setting goals and behavior performance.