Patient-centered care implies that patients, their values, preferences, and individual life and health goals are at the heart of care processes and that patients are involved in care decisions. To be able to make informed choices based on their individual preferences, patients need to be adequately informed about treatment options and their potential outcomes. This implies that studies measure the effects of care based on parameters that are relevant to patients. In a previous scoping review, we found a wide variety of supposedly patient-relevant parameters that equally addressed processes and outcomes of care.