Re: Hofmann et al. Overdiagnosis, one concept, three perspectives, and a model.

It is with great interest we have read the article "Overdiagnosis: one concept, three perspectives, and a model" by Hofmann and colleagues. We share the authors' ambition of understanding what overdiagnosis is and what it isn't. In our research, we define overdiagnosis on the basis of two interrelated phenomena: overdetection and overdefinition. Overdetection is the labelling of a person with a disease or abnormal condition, that would not have caused the person harm, e.g., symptoms or death, if left undiscovered. Overdefinition is the creation of new diagnoses by overmedicalising ordinary life experiences or expanding existing diagnoses by lowering thresholds or widening diagnostic criteria, without evidence of improved outcomes. These phenomena have different causes and thereby often different drivers. However, they have one important consequence in common: people are turned into patients unnecessarily, i.e., overdiagnosed. On a personal level, overdiagnosis cause various types of harms, including physical, psychological, social and financial harm. On a societal level, overdiagnosis may also cause harm to public health, cause resource waste, and cultural changes with overmedicalisation of normal life events. By definition, none of the aforementioned phenomena lead to any clinical benefit. Therefore, we disagree with Hofmann and colleagues' definition of overdiagnosis as diagnoses that "…on balance, do more harm than good.". We argue that introducing balance and benefits to the definition of overdiagnosis complicates the concept unnecessarily and cause problems operationalising overdiagnosis.