ABSTRACT
Overdiagnosis and overtreatment occur when tests and treatments are given without a net benefit to the patient, or where they result in a net harm. This problem is common in healthcare, where it is estimated that around 30 per cent of healthcare is of low or no value, and a further 10 per cent is harmful. As well as providing no benefit to the recipient of care and the lost opportunity and financial costs, low-value care also harms the environment, which in turn increases environment-related threats to human health. The drivers of overdiagnosis and overtreatment arise from our perception of not treating patients as a failure to care, the inherent overestimation of benefit and underestimation of harm when considering medical interventions, the use of increasingly sensitive tests and an increasing variety of treatments, a lack of scientific rigour in the production and evaluation of the evidence around tests and treatments (and sometimes simply a lack of evidence), and the healthcare system itself, which rewards healthcare activity rather than health.
