To address the lack of access to tests and testing services in multiple countries, WHO since 2018 has published a yearly essential diagnostics list (EDL), a basket of recommended in vitro diagnostics that should be available at point-of-care and in laboratories in all countries to increase timely and life-saving diagnoses.
The latest edition, published today, includes WHO-recommended Covid-19 tests (PCR and Antigen), expands the suite of tests for vaccine-preventable and infectious diseases and non-communicable diseases (such as cancer and diabetes), and introduces a section on endocrinology, which is important for reproductive and women’s health. For the first time, the list includes tests that should not be supplied in countries because they are not cost-effective, are unreliable, or have been surpassed by newer, easier to use technologies.
“Access to quality tests and laboratory services is like having a good radar system that gets you where you need to go. Without it, you’re flying blind,” said WHO Director-General Dr Tedros Adhanom Ghebreyesus. “I urge all countries to strengthen testing services and use the essential diagnostics list to drive better care and better health.”
The use of accurate, quality diagnostics is the first step in the development and implementation of strategies for treatment, control, and in many cases prevention of disease and outbreaks. Their critical role in the health system has been brought into sharp focus by the current Covid-19 pandemic.
‘Testing affects the majority of medical decisions,’ said Dr Mariângela Simão, WHO Assistant-Director General for Access to Medicines and Health Products. ‘In all countries, the use of appropriate diagnostic tests can help inform evidence-based treatment and responsible use of medicines, resulting in improved allocation of resources and better health outcomes.’
The EDL is an evidence-based guide that looks at disease prevalence globally and for each condition recommends the appropriate test. That guidance aims not only to improve the health system’s capacity to reach accurate diagnoses, it also saves precious health resources that would otherwise be wasted on inappropriate treatment or lengthy hospital stays.
As well as tests intended for use in laboratories, the EDL recommends numerous diagnostics that should be available at primary care or community level. This is particularly important for rural areas in low- and middle-income countries, where medical facilities and equipment may be lacking and health providers are often forced to make treatment decisions based solely on patient symptoms.
The recommendations in the list are based on robust evidence and take into account country suitability. The process is overseen by the Strategic Advisory Group of Experts on In Vitro Diagnostics (SAGE IVD), a group of specialists from around the world with long standing experience in the field of IVDs and their implementation, their use, regulation and evaluation. The experts evaluate data on the usefulness, impact and accuracy of each test considered in order to decide which should be recommended.
The EDL is not prescriptive – it is intended as a policy tool for countries to create their own national lists based on their local context and needs. WHO will shortly also publish a step-by-step guide to aid countries wishing to develop a national list. So far, WHO has worked with Nigeria, India, Bangladesh and Pakistan to support the development of their national EDLs and is currently in discussions with additional mostly African countries that have requested assistance to boost their diagnostic services.