Proposal from WHO to establish an Essential Diagnostics List (EDL)

By Madhukar Pai Moderator | 30 Jan, 2017


I am excited to see this proposal from WHO to establish a WHO Model List of Essential In Vitro Diagnostics (EDL), submitted to the next Expert Committee meeting for comments and recommendations about the relevance, scope and the best course of action for developing the list, building on the Essential Medicines List experience.

PDF attached.

You may be aware of a series of journal articles, op-eds, and open letters on the need to create an EDL:



The Conversation:

Letter to WHO from GHTC:

What are you thoughts on the WHO proposal? Can we provide helpful comments to WHO on this process?

All comments on this forum can be collated and shared with the WHO team working on EDL. I am happy to do that.


Madhu Pai

Prof Madhukar Pai, MD, PhD
Canada Research Chair in Epidemiology & Global Health
Director, McGill Global Health Programs
Associate Director, McGill International TB Centre



Sanjay Sarin Replied at 9:54 PM, 30 Jan 2017

Dear Madhu
This is a great idea and a much needed initiative to drive access to essential diagnostics on the lines of essential medicine list. This will also help improve affordability both in the public and private sector at the country level as in the case of medicines and devices, a large number of which are now being brought under price control mechanisms. It may be a good idea to constitute groups at country levels to initiate discussions on how to engage the country govts at an early stage. There groups can consist of partners from key organisations, WHO country offices, industry associations, academia, parliamentarians and insurance companies.


Madhukar Pai Moderator Replied at 9:58 PM, 30 Jan 2017

I fully agree, Sanjay. India has done a great job of using the Essential Medicines List to ensure that prices of drugs are kept affordable. There is no reason why India cannot do something similar with essential diagnostics.

While WHO is working on a global list, it will be very nice if one or two countries developed their own national EDLs. The lessons learnt can then be fed back to WHO for policy revisions.


Lee Schroeder Replied at 10:37 PM, 30 Jan 2017

This is truly amazing to see the WHO supporting this concept and proposing a solution! And so fortunate that the moderators have put together this group. Great timing!
This is a fantastic venue to put some careful thought into the WHO proposal. We have nearly two months to put together commentary for the Expert Committee meeting, so plenty of time to explore the many dimensions of an EDL.

Here’s a list of issues I’ll throw out there that I think could use discussion over time:
1) What is the value of an EDL? This needs to be firmly established
a. Value to clinical care and patient outcomes, antimicrobial resistance, and emerging infectious threats
b. Value the EDL could bring to reducing costs through bulk purchasing and pooling mechanisms
c. Value the EDL could bring to quality of diagnostic devices: regulatory approval of devices, accreditation of labs, improved training, increased confidence in results
d. Value the EDL could bring to the supply chain problem and courier of samples
e. Value the EDL could have on informing R&D of novel diagnostics
f. Examples of country-level diagnostics lists (e.g. CLIA regulated analytes) and successes/problems
2) Developing the EDL
a. What should the guiding principles/requirements be for addition of a test to the EDL?
b. Should the EDL include types of tests (e.g., immunoassay for HIV), or actual products?
c. How should the EDL approach the problem of recommending tests for different levels (tiers) in the health system?
d. Should it be strictly tied to the EML (as in companion diagnostics)?
e. Should the list include diagnostics other than in-vitro diagnostics (e.g., radiology, ekg)?
3) How to advocate for the EDL and to garner country-level support?
4) Potential problems with an EDL
a. Unintended consequences of an EDL
b. Obstacles to implementation of an EDL at the global- or country-level
c. Lessons learned from the EML and how prior mistakes can be avoided
5) Which tests to consider initally?
a. Appropriateness of the Annex part A list (priority conditions/tests with strong support programs and guidelines for diagnostics)
b. Appropriateness of the Annex part B list (priority conditions/tests with weaker support programs)


Lee Schroeder Replied at 10:52 PM, 30 Jan 2017

Well, so much for the formatting of that last email!

Sanjay, those are great ideas. With all the focus on the Global Health Security Agenda, I feel that diagnostics are becoming more and more on the radar of health systems and that country governments may be receptive to preparing for (or creating) a national EDL. Or, even advocating for the WHO to establish the EDL.


Madhukar Pai Moderator Replied at 7:08 AM, 31 Jan 2017


Is anyone aware of any country which has its own national Essential Dx List? It will be great to see how they have done it.

If none exists, then this WHO proposal is absolutely critical to get the ball rolling.

My hunch says most governments have not considered an EDL, since drugs and vaccines get all the attention. So, advocacy is necessary, even after WHO puts out a Model EDL.



Lee Schroeder Replied at 12:16 PM, 31 Jan 2017

I don't know of a national level EDL, though the U.S. CLIA regulated analytes list captures some of the essence. This list defines the tests that are to be regulated at a higher level for quality. For example, tests on this list (unless approved in a waived format) are regulated by proficiency testing. In addition to guiding test utilization and bringing costs down, we're hoping that an EDL will help improve quality of testing. It could do so if a country would, for instance, require proficiency testing for non-waived EDL tests.

Lee Schroeder Replied at 6:07 PM, 31 Jan 2017

An EDL can be formalized by the WHO, but many obstacles remain before reaping the benefits. One of these has to do with supply chains and courier of samples between tiers in the health system. In ramping up early infant detection for HIV, Uganda strengthened it's courier system with a hub model. See attached. Reduced transport costs by 62% and turn-around times by 47%. I think countries will need to think seriously about formalizing transport of samples and possibly supply chain mechanisms for reagents of essential diagnostics.


Attached resource:

Sanjay Sarin Replied at 10:59 PM, 31 Jan 2017

The govt of India has launched a free diagnostics initiative to offer certain essential diagnostics tests via public health care facilities across the countries which are already being implemented by a number of states. See attached the operational guidelines for the FreeDiagnostics Initiative. The type of tests to be offered free vary depending upon the level of facility (primary health centre, community health centre, district hospital etc)

Francis Moussy Replied at 9:58 AM, 1 Feb 2017

Dear all,

I am thankful to Madhu for having started the discussion on the proposed List of Essential In Vitro Diagnostics on this forum and to the others for the comments that have already been posted. I am reading the comments with great interest. Thanks for contributing.
Best regards

Francis Moussy
List of Essential In Vitro Diagnostics
World Health Organization

Lee Schroeder Replied at 12:28 PM, 2 Feb 2017


The Indian "Free Diagnostics Service Initiative" is quite impressive. The guidelines touch on breadth of testing, quality, supply chains, PPP...seems like an ideal program to study and learn from.

Do you know if there are any impact analyses in process? Or, estimates of the costs?


Sanjay Sarin Replied at 6:45 PM, 2 Feb 2017

Am not aware of any impact analyses but will check and revert. On the costing part, will vary from state depending upon the number of patients accessing services.


Prashant Yadav Replied at 12:36 AM, 3 Feb 2017

Madhu and Lee,
Thanks for initiating a thought provoking discussion.
The value of an essential list for diagnostics list rests on whether products on the essential list would be prioritized for procurement, reimbursement and quality assurance. Also, clinical guidelines would have to be changed to ensure they are completely in sync with the diagnostics on the essential list. Drawing up a list is easier but having countries put monies for purchasing, better quality regulation and creating well functioning distribution systems for the products on the essential Dx list is much much harder.

The essential medicines list (EML) have undoubtedly helped rationalize and focus procurement and quality assurance efforts. After 30 years of concerted efforts a large number of developing and However, as is evident in numerous surveys, the availability of medicines on the EML in public sector clinics still remains abysmal in a vast majority of low and lower middle income countries. So having an EML by no means implies those products were adequately financed or procured.

In some countries, even when there is some reasonable procurement for products on the EML, the Standard Treatment Guidelines dont necessarily tally with products on the EML. Revising these things through the consultative processes involved doesn't always work in sync and they often get staggered by years, in terms of when each gets updated.

Re using the Essential Dx list to signal to product developers, industry, and donors where funding and attention is needed to facilitate R&D, I feel there are easier mechanisms to achieve that, instead of the time and resources required to create EDxL

When you ask colleagues from the pharmaceutical industry, most of them still think that the Essential Medicines List is something used only for public sector procurement in the poorest countries. And in many cases they are right, because the assortment of products stocked and promoted by the private sector is driven by channel economics and not necessarily the EML.

So would the Essential Dx List be only for public sector procurement or for the health sector as a whole? If it is for the health sector as a whole, then its worth asking what policy levers does the government have in a predominantly out-of-pocket Dx services market to influence what products the private wholesalers,distributors and labs will stock and promote?

Some countries (especially those with very high out of pocket medicines market) have used the EML not so much for actually purchasing the products on the EML but more as a list for price control. So if an essential diagnostic list gets created without adequate financial resources, it will most likely be used as a basis for price regulation and not for increasing pooled financing for Dx. That outcome may have some advantages but also some disadvantages.

I am sure transparency and rigor can be instituted in the process to draw up the list, but how to factor in cost-effectiveness and affordability will remain a challenging issue. Product price that goes into cost effectiveness models is often assumed as static but we know we have multiple levers to influence the price.

So in summary, I feel there are LOTS of unanswered questions. Some technical/clinical, some economic, and some political. Lee has started to highlight some of the technical ones. Hopefully, this forum and other convenings you create will help get to the bottom of the others before embarking on drawing out an EDxL.

Madhukar Pai Moderator Replied at 6:52 AM, 3 Feb 2017

Thanks, Prashant, for the valuable insights.

There are many upstream, technical issues to sort (how to create the list, which diseases to include, IVDs only, etc), and what you have listed is the downstream issues on how countries are currently executing the EML and what follow-up work is necessary to make sure an EDL, once developed, is implemented in a way that is impactful. It will be important to work with a few countries to convert the WHO model EDL into a national EDL, and see how things play out at the country level.

We definitely need to learn from the lessons that EML has taught us and proactively incorporate those into the EDL process.

What is the best resource for lessons learnt from EML? Is there a good case study??


Mark McCaul Replied at 8:13 AM, 3 Feb 2017

This is a very interesting discussion.
The downstream issues (political, economic, and supply chain) appear to be the same as HIV and the representative number of TB drugs, diagnostic process, and equipment could be small enough that it would potentially not represent a substantial increase in time or resources for the current and multiple HIV initiatives, though I know that there have been many criticisms to this approach.

In my opinion, focusing on converting the WHO EDL to the national level would either happen organically or not have the impact that we would like to see.

I don't think there are many case studies available.. but this is one potential focus for me in the next years for anyone who has interesting information to share.

Jeannette Guarner Replied at 9:29 AM, 3 Feb 2017

The "essential diagnostic/test list" is definitively needed. Many of the tests are basic and can serve for diagnosis or monitoring of more than one of the diagnosis that are treated by the current "essential medication list".

Lee Schroeder Replied at 3:06 PM, 3 Feb 2017

I absolutely agree that case studies in EML would be extremely valuable. I’ve read a handful of evaluations/surveys and many tell a similar story: While EML has helped overall for access, availability is still far from desirable. However, the attached UN document reports little improvement from 2007-2011 vs earlier (p. 61; though different survey methods). On the other hand, there’s a ppt on the WHO website reporting that access has doubled since inception of the EML. Both claims may be true.

Here’s the WHO data on current EML medicine availability:

In summary, the question of the impact of EML on access is a little unclear to me. I think there’s no question access needs to be improved, but without the EML, the situation may have been even worse. If anyone knows of relevant studies, please share.

Finally, I’ve attached an IIHI report on EML that I found valuable.


Attached resource:

Lee Schroeder Replied at 3:07 PM, 3 Feb 2017

Seems the IIHI report didn't take (see attached)

Attached resource:

Lee Schroeder Replied at 4:03 PM, 3 Feb 2017

As for the EML and quality, see attached for one study. The report looks into the association of country-level essential medicine policy uptake and the quality use of medicines. They found the following essential medicine policies most associated with improved quality use:

-undergraduate training of doctors in standard treatment guidelines
-undergraduate training of nurses in standard treatment guidelines
-the ministry of health having a unit promoting rational use of medicines
-provision of essential medicines free at point of care to all patients

An EDL could certainly aim for a similar impact on quality and essential diagnostics policies could be recommended to countries.

I'd like to hear opinions on whether the issue of quality is one lever that could be used in the private sector. Even if private sector test menus might not be impacted significantly by an EDL, a country could regulate the quality of labs performing tests listed on the EDL, whether public or private. It would raise costs, but hopefully quality and confidence in lab testing as well.


Attached resource:

Madhukar Pai Moderator Replied at 12:47 PM, 4 Feb 2017

Hi All,

Check out this post by GHTC about the EDL proposal by WHO:


Prashant Yadav Replied at 2:39 AM, 6 Feb 2017

The report of the Lancet Commission on Essential Medicines and Policy may be another one to add to your list.

Lee Schroeder Replied at 11:38 AM, 7 Feb 2017

Madhu, Tim and I put together some thoughts to provide as commentary to the WHO proposal for an Essential Diagnostics List. We plan to formally submit to the Expert Committee on the Selection and Use of Essential Medicines sometime next week. See the attachment.

If you can spare the time, please provide feedback and we can incorporate comments.

Prashant, thanks for sharing the great reference.


Attached resource: