Mediation test of a randomized controlled trial.
Women with T2DM (n聽=聽93) from the control group (standard PA materials, n聽=聽44) and the full intervention group (control聽+聽stage-matched printed material and telephone counseling, n聽=聽49) of a larger PA intervention trial were included. PA outcomes were minutes of MET weighted moderate and vigorous PA/week (self-report) and steps/3-days (objective) recorded at baseline and 12-months. Social-cognitive constructs were measured and tested in a mediating variable framework.
Perceived behavioral control and barrier self-efficacy mediated intervention effects on objective PA (proportion of intervention effect mediated聽=聽18% and 24% respectively). Intention was a mediator of objective PA (23%).
Perceived behavior control, barrier self-efficacy, and intention are effective mechanisms of PA behavior change in women with T2DM.