In order to reveal these conceptual cores, we grouped the recurrent themes presented in the articles into three interconnected levels that form a model for each concept, unifying them structurally, but allowing for wide differences at the same time: (1) at the base of the model, a core assumption or requirement on which the concept rests; (2) at the center, an intervention level in which the professional-patient interaction takes place, referred to as the action; and (3) at the top, an aim which the intervention strives to achieve, referred to as the purpose. Please refer to