The present pilot study is a precursor for a following larger trial and aims to evaluate the i) feasibility, ii) validity, and iii) preliminary efficacy of the three treatment components that will be further investigated in a subsequent larger trial. The present pilot study will employ the same design as will be used in the subsequent larger trial, namely the Multiphase Optimization Strategy (MOST). Specifically, in the subsequent larger trial, MOST will be used to evaluate the efficacy and change processes of three psychological treatment components selected from so-called third wave cognitive therapies (CTs), which have been shown to be efficacious in the treatment of pain after breast cancer.~The overall hypothesis is that the selected third wave CT components will target key maintaining psychological factors in pain, thus leading to reductions in the primary outcomes of pain intensity and -interference. Specifically, we hypothesize that:~Mindful attention practices will increase attentional control (i.e., the ability to intentionally focus and intentionally shift one's attention), thereby reducing pain hypervigilance, leading to reductions in pain intensity and -interference.~Decentering practices will reduce fusion with thoughts (i.e., getting caught up in one's thoughts and acting automatically in response to thoughts), thereby reducing pain catastrophizing, leading to reductions in pain intensity and -interference.~Values and committed action (i.e., behavior linked to values and goals) will increase acceptance of discomfort and reduce avoidant behavior, leading to reductions in pain intensity and -interference.
The present study is a pilot study that aims to evaluate the feasibility, validity, and preliminary efficacy of three psychological treatment components for pain after breast cancer, which will be evaluated in a larger trial following completion of the present pilot study.