Discussion
This primary analysis report evaluated outcomes of the psychological adherence program PrevOP-PAP that was designed to enhance PA and reduce OAK symptoms (WOMAC) among patients with moderate OAK. The intervention program PrevOP-PAP adopted motivational, volitional, and networking intervention strategies based on the HAPA to support OAK patients’ uptake and maintenance of regular MVPA and reduce OAK symptoms (WOMAC). Intervention effects were contrasted with the PrevOP-PAP active control condition, in which participants only received the motivational intervention. As the primary hypothesis, it was assumed that participants of the PrevOP-PAP intervention condition (compared with participants of the PrevOP-PAP active control condition) would engage in more MVPA at the end of the active intervention phase which would then translate to lower levels of OAK symptoms (WOMAC) at the end of the study period. Present findings did not confirm the proposed intervention effects on overall OAK symptoms (WOMAC) or MVPA. Moreover, MVPA did not mediate the association between the intervention and OAK symptoms (WOMAC).