Title: Challenges in ensuring that the evaluation of medical tests helps to improve patient health

Abstract:

Health care organisations around the world need to make recommendations of the choice and provision of medical tests. In 2018, the WHO for the first time, published the Essential Diagnostic Tests (the EDL) listing in vitro diagnostics which should be available around the world to ensure Universal Health Coverage. In doing so they have faced challenges in identifying evidence required to make rational decisions about test selection. Ideally medical tests, as with interventions, should be recommended for use when there is evidence that they do more good than harm. However, medical tests rarely directly improve patient outcomes – rather the medical interventions that are taken consequent on use of a test create benefit for patients – and it is rare to be able to obtain evidence that shows how tests save lives. Whilst evaluations of diagnostic or prognostic tests have typically focused on their accuracy to predict the numbers receiving appropriate or inappropriate treatment, extrapolating from these data to predict overall patient benefit is not always appropriate. In this talk I will review challenges that health care organisations face in identifying evidence required to assess benefits and harms of testing, drawing on experience working with the WHO EDL.