Introduction
cancer death, Breast cancer, illness suggests illness
BREAST CANCER
Breast cancer is the most common cause of cancer death in women worldwide [Medication beliefs, in the form of low perceived personal need for AET and high concerns about AET (e.g., burden of side effects), are associated with lower AET adherence [An extended version of the self-regulation model of illness suggests illness representations could influence key medication beliefs regarding the necessity or concerns of medication [There is little understanding regarding effective strategies to target medication beliefs [Medication beliefs are complex, and therefore a multicomponent intervention may be needed to target all aspects of the construct. The multiphase optimization strategy (MOST) is a framework used to optimize multicomponent interventions [We aimed to prepare and optimize an information leaflet intervention, aiming to increase necessity beliefs and reduce concerns about AET. We had three objectives: (i) to evaluate the main effects of each component of the information leaflet on beliefs about AET, (ii) to estimate interactions between components of the information leaflet on beliefs about AET, and (iii) to establish an optimal combination of information leaflet components with regard to changing beliefs about AET.