The WHO essential diagnostic list: a tool for the future.

 Prof Adrian Newland on what the WHO essential diagnostic list mean for the future . 

The World Health Organisation’s (WHO) Strategic Advisory Group of Experts on In Vitro Diagnostics (SAGE-IVD) was set up in 2017 to develop a list of essential diagnostic tests to complement the essential medicines list that has been available for over 40 years and being regularly updated .  However, diagnostics drive 70% of health care decisions and it is clear that without an accurate diagnosis inappropriate, wasteful and potentially harmful treatment may be given.  It was with this in mind that WHO developed the diagnostic initiative and the first Essential Diagnostics List was published last month.

Patients do not present with a specific diagnosis but in general are non-specifically unwell. There will be some clinical clues but rapid and accessible screening tests need to be available to point to the more specific investigations appropriate to the patient’s needs. The first essential diagnostics list (EDL) is therefore a catalogue of tests for detecting common morbid conditions and priority diseases. The latter being conditions that WHO has already prioritised by looking at healthcare needs, taking into account disease burden and public health relevance. In assessing the diagnostics evidence of efficacy and accuracy and some degree of comparative cost-effectiveness has also been considered.

It is expected that individual countries or regions will use the list to develop their own national list of diagnostic procedures appropriate to their own healthcare needs and resources. In addition, the regulatory challenges need addressing, in particular quality assurance of testing and accreditation of laboratories.  India is one country that is already well advanced along this route with the development of its Free Diagnostics Service Initiative but others in Africa are working on similar processes.  An additional benefit of producing a basic standard list endorsed by a body such as WHO is that it informs patients what should be available and gives them the impetus to demand appropriate diagnostics.

Although international in approach, this is particularly focused on low and middle income countries and is designed to suggest diagnostics that are appropriate at all levels of healthcare; community, primary care, district hospital, major centre and referral diagnostic centre. Some of the tests listed are particularly suitable for primary healthcare facilities, where laboratory services are often poorly resourced and sometimes non-existent, tests that do not require electricity or trained personnel. Other tests are more sophisticated and therefore intended for larger medical facilities. This will aid the development of integrated and tiered diagnostic facilities on a country-wide basis in these countries and also aid procurement, with bulk purchasing and economies of scale.  This should help reduce costs and improve the affordability of tests for the patient and by facilitating diagnosis should reduce inappropriate treatment.  If an outcome is the reduced use of antibiotics then this will be a major bonus.

The EDL contains 113 items – 58 tests are listed for detection and diagnosis of a wide range of common conditions, providing an essential package that can form the basis for screening and management of patients. This covers basic conditions such as anaemia, cardiac disease, diabetes, liver and kidney disease and simple infections.  The remaining 55 tests are designed for the detection, diagnosis and monitoring of ‘priority’ diseases such as HIV, TB, malaria, hepatitis B & C, human papillomavirus and syphilis. For each category of test, the EDL specifies the type of test and intended use, format and whether it is appropriate for primary healthcare or for health facilities with labs. Where available, tests that are already WHO prequalified products are listed.

The biggest challenges in providing appropriate diagnostics relate to human resources (both numbers and training), facilities, healthcare funding and basics, such as a stable electricity supply and laboratory grade water supplies.The diagnostics need to be tailored to facilities (i.e. particularly what can be used in the community and outside the standard laboratory setting) to establish a potential diagnosis, and how this can be followed up in more central laboratory settings where automated diagnostics, immunoassays and up-to-date molecular genetics can be offered. Our recommendations cover a range of diagnostics that allows each country to look at what they should provide, and where, in the light of their current provision and resources.

In addition, by looking at diagnostics on a wider scale some of the developments in point-of-care molecular diagnostics, digital pathology and the use of artificial intelligence can be rolled out as appropriate and will significantly aid diagnostics and the efficiencies predicted will reduce costs. Currently in England the centralisation and economies of scale that are taking place are predicted to save £200m in pathology diagnostic costs.

By launching the EDL, the WHO aims at providing a tool for all countries to use so that they can utilise health funds efficiently by concentrating on the truly essential tests.

“An accurate diagnosis is the first step to getting effective treatment. No one should suffer or die because of lack of diagnostic services, or because the right tests were not available,” Dr Tedros Adhanom Ghebreyesus, WHO Director-General, said in a statement.

The list will be updated on an annual basis and in the coming months, WHO will issue a call for applications to add categories to the next edition. It is expected to expand significantly by incorporating important areas such as antimicrobial resistance, emerging pathogens, neglected tropical diseases and additional non-communicable diseases.

About the author:

Adrian Newland is Professor of Haematology at Barts and the London School of Medicine and Dentistry and Honorary Consultant at Barts Health NHS Trust, London, UK. He is currently the Chair of the Healthcare Forum for the UK Accreditation Service and   is the national advisor to NHS Improvement on Pathology. He is also a member of the WHO Strategic Advisory Group of Experts on In Vitro Diagnostics (SAGE IVD)


Competing Interest: I have read and understood the BMJ Group Conflicts of Interests Policy and Declare I do not have any conflicts of interests


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