Effects of the PrevOP-PAP intervention on MVPA and its HAPA-proposed volitional precursors
pain
DISEASE
Importantly, the question arises why participants did not increase their MVPA during the intervention period. On the one hand, increases in intentions to engage in regular MVPA one week after the motivational intervention indicated a successful motivational manipulation for all participants. However, manipulation checks of the PrevOP-PAP intervention yielded only one effect on the HAPA-proposed volitional precursors of MVPA change at the end of the study period. At 24 months following study entry, only action planning showed a significant increase in the PrevOP-PAP intervention condition (vs. PrevOP-PAP active control condition). The finding on intervention effects for action planning is in line with prior findings in the context of cardiac and orthopedic rehabilitation [In this context, coping planning and action control have been highlighted as important additional key intervention components to enhance the effects of action planning [Regarding the null effect on action control, three one-month paper–pencil activity calendar phases delivered throughout the PrevOP-PAP intervention with extended periods of no intervention delivery might not have been sufficient to foster action control in the long run. Future research could implement m-health self-monitoring applications which are permanently available to facilitate continuous and long-term action control.Furthermore, the overall moderate OAK severity and prolonged disease duration in our sample as well as a decrease in pain in the intervention condition might further explain null effects of the PrevOP-PAP intervention on changes in self-efficacy. With decreasing salience of barriers or decreasing barriers, such as pain, over time, increases in behavior-specific self-efficacy become less likely, because self-efficacy is always measured up against perceived difficulties or barriers to act. Also, with regard to the social network formation indicator, i.e., collaborative implementation intentions, the PrevOP-PAP intervention did not yield significant intervention effects and many participants of the intervention condition decided not to participate in the optional network creation intervention. As vicarious experiences and positive affective states experienced in social networks serve as sources of self-efficacy, this might also have affected levels of self-efficacy in our sample [On the other hand, when interpreting null effects on MVPA, it must be noted that participants demonstrated relatively high baseline levels of MVPA (i.e., on average around 47 min per day) when compared to previously reported levels of MVPA among patients with OAK [