Figure 2.

HAPA engagement longitudinal model (60). In the motivational phase, pre-engagement self-efficacy, outcome expectations, perceived need, and trauma symptoms significantly predicted the formation of intentions. In the volitional phase, intentions were translated into engagement, mediated by planning and moderated by low levels of engagement self-efficacy (−1 SD). Engagement is a latent construct consisting of both subjective (estimated frequency and duration) and objective measures. Objective measures were continuously measured by the digital health intervention. *P<0.01, **P<0.001, T1 = time 1, T2 = time 2, T3 = time 3. HAPA, health action process approach.