5 Overdiagnosis in multimorbidity: a global challenge

The number of people living with multimorbidity has increased dramatically during the last decades, which is associated with harms and costs for individuals as well as societies. This increase is explained by population longevity, but also by better medical treatment and tertiary prevention among patients with chronic diseases. However, the increased prevalence of multimorbidity may owe to the inconsistency of the definition of multimorbidity, which leaves room for both under- and overdiagnosis. The consequences of this overdiagnosis will plausibly have influence on the handling and daily clinical practice regarding the growing number of patients categorized as multimorbid. The theoretical background and hypotheses for the risks of overdiagnosis within multimorbidity concerns a lot of different aspects. Some of the aspects comprise different possibilities for overdiagnosis of diseases. Moreover, some of these diseases have different prognoses and have different meanings, values and treatment preferences for patients. Therefore, it could be relevant in a patient-centred approach for clinicians to conduct a diagnostic review and in dialogue with the patients find out which diagnoses are of importance and which could de-diagnosed. In this workshop we will invite participants to attend the discussion about drivers of overdiagnosis in relation to multimorbidity, and how we can study these problems scientifically. Furthermore, the aim of the workshop is to discuss whether a too broad definition of multimorbidity may result in more harm than benefit for the patients. Finally, we will discuss if diagnostic review in a primary health care setting is a relevant and appropriate approach among patients with multimorbidity who have been overdiagnosed with one or more diseases.