For the past couple of years, laboratory experts have called for a worldwide essential diagnostics list (EDL), akin to the World Health Organization’s (WHO) Model List of Essential Medicines (EML), to help focus global health policy. It appears that 2018 will be the EDL’s start, with a first draft published in March on the WHO website.

WHO also has formed its first Strategic Advisory Group of Experts on In Vitro Diagnostics (SAGE IVD) committee, comprising 18 members with a broad range of expertise related to laboratory testing, test evaluation methodologies, and regulatory aspects at various levels of the health system, and from all six WHO regions including developing countries, said Francis Moussy, PhD, an adviser for the EDL and SAGE IVD in WHO’s Department of Essential Medicines and Health Products. As CLN went to press, committee members’ names and biographies were due to be published on the WHO website in advance of the group’s first meeting, planned for April 16-20 in Geneva.

A first draft for the EDL is now under development, Moussy said, following recommendations last year from WHO’s Expert Committee on the Selection and Use of Essential Medicines. The first iteration will focus on infectious diseases such as tuberculosis, malaria, HIV, and hepatitis B and C. Subsequent versions will expand to other areas such as biochemical testing and noncommunicable diseases, according to Moussy. “We anticipate that the list will be revised or expanded on an annual basis,” he said. WHO expects to launch the list by the end of August.

“The EDL is intended to provide evidence-based guidance to countries to create their own national lists of essential in vitro diagnostic tests,” Moussy said. He noted that national EMLs have been successful in raising awareness, guiding procurement and regulation policies, and facilitating access to affordable medicines, particularly in low-resource countries, by prioritizing the most important medicines countries should make available to their populations. “It is expected that national EDLs will provide similar benefits and improve access to affordable diagnostic tests,” said Moussy.

Concentrating Resources

The list should focus countries’ attentions on which tests are most appropriate, said Timothy Amukele, MD, PhD, an assistant professor of pathology at the Johns Hopkins University School of Medicine in Baltimore.

“Running laboratories is complex,” said Amukele. “You have to have a steady, consistent supply chain, things at the right temperatures, some things expire at different rates. In a lot of poor countries, reagents are not made locally, so they have to order them with enough time to receive the specimens and still have them be useful in the lab.” The challenges labs in developing countries face span the gamut of operations, he added. “There’s a whole list of training requirements needed to perform testing, and those requirements vary by how complicated the test is. There’s all the stuff we need to do to assure quality ... and then there are funding issues. In a lot of environments, even salaries are not consistent, so just trying to make a lab work in that kind of setting can be very challenging.”

The EDL “would help to simplify all that,” Amukele suggested. “It would say for this country, given your disease burden, these are the top 20 tests that we think are most essential. Then everyone would be able to focus on that.” While the list doesn’t restrict countries from doing more than the minimum, “it says if you want the biggest bang for your buck, this is where you should be looking,” he emphasized.

A Changing Tide

While there hasn’t been a lot of focused international attention on diagnostics, that appears to be changing, added Lee F. Schroeder, MD, PhD, an assistant professor and director of point-of-care testing at the University of Michigan in Ann Arbor. “I think people are realizing that even for the really simple tasks, like rapid diagnostic tests for malaria, that you need a laboratory system behind them for quality assurance, supply chains, and so forth,” he said.

The focus on laboratories has been driven by a few factors, Schroeder said. First, efforts to control HIV, tuberculosis, and malaria have highlighted a need for diagnostics. “Pretty much every time a new guideline comes out, there’s a greater emphasis on laboratory testing,” he said. Then there are concerns for surveillance of outbreaks for conditions like severe acute respiratory syndrome, Ebola, and Zika, and laboratory systems are an important part of that. Add in antimicrobial resistance, which is estimated to cost an accumulated $100 trillion by 2050 if current practices continue along the same path. “While medicines have had this organizing principle (in the EML), diagnostics have not, and that’s why I think there is interest in establishing the EDL now,” Schroeder added.

Schroeder, Amukele, and others called for an EDL in 2016. In a New England Journal of Medicine article, they identified 19 test categories they found to be essential for the effective and safe use of at least 10 medicines or medicine combinations that appear in the core EML (N Engl J Med 2016; 374:2511-4). “These included tests like electrolytes that are useful for general clinical care, as well as targeted diagnostics for specific conditions like microbiological nucleic acid testing and hemoglobin A1c,” Schroeder said.

As a follow-up, the authors have been working on an expanded list of tests indicated for use with both the core and complementary EML medicines. “In terms of number of indications, the tests found at the top include, perhaps not surprisingly, the workhorses of clinical laboratories like the complete blood count, comprehensive metabolic panel, and bacterial culture,” said Schroeder. These tests not only diagnose diseases “but many in these panels are also critical for monitoring toxicity to drugs as well as identifying end-organ disease from any number of conditions. The number of indications that pop up for these dwarf the others.” Schroeder and his colleagues will be submitting their manuscript soon to a journal for publication.

Country-specific Lists?

Customizing the EDL by country could present some challenges, Amukele noted. For example, meningitis outbreaks cut across the Sahel region in Africa and are somewhat predictable, occurring every year or two. “It would be really important for them to have that testing in that region of the world, but the same would not be true in a lot of Asia. It would still be nice, but it probably won’t be as critical. That’s where the work needs to be done—coming up with lists and customizing them by country based on the disease burden by region.”

Countries have applied different approaches to prioritize their diagnostic needs, and the EDL “is an additional but powerful tool to achieve this goal,” said Eileen Burke, a laboratory specialist at The Global Fund, an international financing organization that supports countries’ responses to AIDS, tuberculosis, and malaria. She believes the EDL will improve the efficiency of limited resources for health service delivery. “The tool applies the 80:20 rule, which helps identify the 20 percent of diagnostics that account for 80 percent of a population’s lab service needs,” said Burke. “That results in greater impact and efficiency in the supply chain operations because of having a rationalized list of lab commodities.”

Given the low relative cost of laboratory testing in the U.S. health system in comparison to its valuable role in healthcare decision-making, implementing the EDL is likely to be a cost-effective investment in resource-limited settings, Schroeder said. But perhaps because lab testing represents such a small percentage of overall health spending, it doesn’t always take a front seat in the planning of healthcare systems, he said, adding that labs that develop ad hoc are subject to quality problems. “The hope is the EDL will put laboratory medicine systems on the country-level and global health agendas to help focus the attention of all stakeholders to solve some of these problems,” he said. “It’s not as if you need new technology here. This is just about getting basic healthcare service to a population of people experiencing an enormous burden of disease.”

Drs. Amukele and Schroeder will jointly present a plenary session on essential diagnostics at the 70th AACC Annual Scientific Meeting & Clinical Lab Expo. More information on the EDL is available at

Karen Blum is a freelance medical/science writer in Owings Mills, Maryland. Email: