Temporal Sequencing of Physical Activity Change Constructs within the Transtheoretical Model.

OBJECTIVE: Studies support the Transtheoretical Model's (TTM) ability to describe behavior change processes and guide interventions; however, the temporal sequencing of constructs is less understood. This cohort study tested five sequences to identify TTM construct changes related to physical activity. METHODS: A random sample provided baseline data (n=689; 63% female; M age (SD)=47(17); 37% white), with 401 participants providing 24-month data, at six-month intervals. RESULTS: Structural equation models revealed processes to cognitions to stage (AIC=29313.093, BIC=29514.883, CFI=0.999, RMSEA=0.006, SRMR=0.026); processes to stage to cognitions (AIC=27788.651, BIC=27973.268, CFI=0.978, RMSEA=0.024, SRMR=0.038), self-efficacy/temptations to processes to decisional balance to stage (AIC=13914.771, BIC=14031.169, CFI=0.981, RMSEA=0.018, SRMR=0.034), and stage to processes to cognitions (AIC=22048.324, BIC=22212.986, CFI=0.976, RMSEA=0.026, SRMR=0.029) all fit well. However, cognitions to processes to stage did not fit the data well (AIC=10353.555, BIC=10444.179, CFI=0.937, RMSEA=0.038, SRMR=0.035). CONCLUSIONS: Integrating results revealed a cyclical model so that intervention efforts should focus on processes to change cognitions related to barrier self-efficacy and decisional balance, which then lead to change in stage and then renew focus on the processes.