Medicines are important to treat disease but diagnostic tests are equally important to find disease. Diagnostic tests help manage both communicable and noncommunicable diseases and survey emerging infectious threats such as the Ebola and Zika viruses.
Without diagnostic tests, health care providers are forced to rely on clinical symptoms that often overlap between conditions. For example, take a child with a bacterial sepsis, pneumonia, or malaria. To even the most seasoned physician, these diagnoses can be indistinguishable. The wrong guess leads to the wrong treatment, an overuse of antibiotics and often a poor outcome for the child.
This problem is all too common in sub-Saharan Africa. In half the countries on the continent 80% of the people treated for malaria are prescribed medication without a laboratory test to confirm the disease. This translates into drastic antibiotic overuse which in turn fuels resistance.
The challenge comes about because there is a striking under-investment in high quality diagnostic testing.
One way to resolve this is to create an essential diagnostics list similar to the World Health Organisation’s Model List of Essential Medicines. This is a list of medications that each country should have at prices that the community can afford.
In the same vein, an essential diagnostics list would detail diagnostic tests that should be available to people who need them. These could range from point-of-care tests in physicians’ offices or in pharmacies to high-complexity tests in reference laboratories.
The end result would be a health system where people were more accurately diagnosed and treated, where disease outbreaks could be identified earlier, and diagnostic tests performed according to a high standard.
Essential medicines
The essential medicines list was first published in 1977 and has been hailed as one of the major public health achievements in the history of the World Health Organisation. Since it introduced the list two decades ago the number of people able to access essential medicines has more than doubled. The list works because it helps governments and other large funders make the most effective investments.
The list of essential diagnostic tests would mean medicines on the essential medicines list could be used in a safer and more rational way. Crafting the diagnostics list to complement these essential medicines addresses the disease priorities that have been identified by the Model List of Essential Medicines.
The essential diagnostics list would be tailored to local burdens of disease in the same way that the Model List of Essential Medicines is designed to be individualised by Ministries of Health.
And as is the case with essential medicines, an expert group could review applications and periodically update the diagnostics list to accommodate improvements in technology and shifting disease epidemiology.
Benefits of a diagnostic list
The essential diagnostic list would be beneficial in many ways. Improved diagnostics capacity would mean that disease outbreaks could be identified earlier. Take the Ebola epidemic in West Africa. The first death is thought to have occurred in December 2013 but Ebola was not recognised until March 2014. The outbreak highlighted the need for diagnostics at multiple tiers in the health system.
Better testing for diseases would also mean that health providers could rely on evidence from laboratory testing before administering medication. Out of necessity many health providers in Africa offer treatment based on clinical suspicion. This is often recommended by the World Health Organisation for regions where testing is unavailable.
Patient outcomes are improved both by the availability of testing as well as strengthening the diagnostic-treatment cascade which involves testing, diagnosis and appropriate medical care. An essential diagnostics list could galvanise changes like this in a health system.
There are broader benefits for the health system.
An essential diagnostics list would act as an organising force for governments, funders, and manufacturers. This would improve affordability of the tests because they could be purchased in a group. This would remove the financial obstacles that often prevent diagnostic testing systems from being successfully implemented.
Implementation begins with pre-market approval of diagnostics. The dissemination of low-quality diagnostics undermines health care delivery. Counterfeit medication has the same effect. Pre-market approval agencies in developing countries are typically underfunded or non-existent.
An essential diagnostics list could simplify the scope to establish regional regulatory bodies for the continent. This would ensure that essential diagnostics sold in-country are reliable.
In addition to acquiring reliable instruments, laboratories must also perform quality testing. In Kampala, Uganda, 95% of all laboratories and 60% of hospital laboratories were rated with the lowest score on the World Health Organisation laboratory quality checklist.
Quality also means consistency of operation. Stock-outs in laboratories across the continent are far too common. This is as a result of inadequate infrastructure and unreliable supply chains. An essential diagnostics list could focus governments’ accreditation programmes on essential tests to ensure quality assurance standards are maintained.
Next steps
The most effective use of medicine requires diagnostics. To strengthen diagnostics an essential diagnostics list is required. Providing essential diagnostics would entail a relatively small investment but could result in large synergies throughout the health care system.
The World Health Organisation – as the steward of the Model List of Essential Medicines – should also be the steward of the essential diagnostics list.
But for the World Health Organisation to be successful, it is critical for international health organisations as well as civil society and donors to support this initiative.
