Stability of and Associations Between Social-Cognitive Determinants Over Time

This study reports on the stability of social-cognitive determinants, and on associations between social-cognitive determinants to show insight in the theory of planned behavior (TPB). In all, 278 health professionals who encourage patients to become physically active completed online TPB-based surveys at baseline (Time 1 [T1]) and six months later (Time 2 [T2]). No intervention took place. No differences were found for all social-cognitive determinants measured at T1 compared with T2 (6 months later), except for intention ( t test = 5.18, p < .001). Structural equation modeling—χ 2 (5, N = 278) = 2.35, p = .80, root mean square error of approximation = 0.00—showed that behavior T1 and attitude T1 predicted intention T1 ( R 2 = .57, p =