In May 2018, the World Health Organization (WHO) published its first edition of a “Model List of Essential in Vitro Diagnostics” (EDL) in which they detail those clinical diagnostic tests which should be (ideally?) available and at which level of healthcare facility. Clearly, developing this list was no small undertaking and WHO is careful to state that the EDL is “not intended to be prescriptive…rather country programmes should make the ultimate decision about [EDLs] selected”. Nonetheless, there are some paradoxical recommendations hard to reconcile with realities. For example, the primary health care facility is delineated as:
“Primary health care: Health centres, doctors’ offices, health posts, outreach clinics. Typically, self-testing and rapid diagnostics tests are available, but there are either no laboratories, or small laboratories with trained health”
The recommendations are that within this setting, a complete blood count should be available. This would require a Hemoglobinometer, Hematology analyzer, and/or a Hemocytometer. So, even if one assumes the cost of these equipment is not prohibitive, in the absence of a laboratory or laboratory technicians, who would be operating the equipment? The already over-burdened non-physician clinician? Who would service and maintain the equipment? Blood chemistries, including liver function tests, are also listed at the primary care level. So, the clinical officer or general medical officer staffing a primary healthcare center would apparently also be expected to master the use of optical and electroanalytic methods. Diagnostic assessments aside, I personally found the EDL indication for “Antisera for agglutination” to facilitate “Blood transfusions” at the primary health care level quite frightening.
Other recommendations, for example to have hand analyzers for PT/INR and lactate levels, would be wonderful. But it boggles the mind to contemplate the costs of purchasing these pricey little devices and their costly consumables. And multiplying that cost to include every primary healthcare facility in a country would be massive indeed.
In reviewing the process used to develop the EDL, the outcome makes more sense. “The general laboratory diagnostics in the first edition of the EDL were compiled based on existing WHO guidance, guidelines and technical manuals and priority medical devices lists”. None of the EDLs listed are unnecessary. They are simply not presently feasible.
WHO defines Essential Diagnostics as “Diagnostics that satisfy the priority health care needs of the population and are selected with due regard to disease prevalence and public health relevance, evidence of efficacy and accuracy, and comparative cost-effectiveness”. If one views the EDL as an aspiration, then you really cannot find any fault with it.
Perhaps the best audience for the EDL is the medical technologies private sector. The list certainly provides insights into priorities and global health issues relevant to diagnostic testing in low income settings and thus offers clear direction for investments and/or philanthropic priorities.
But a call for practical, affordable, point-of-service technologies relevant to common, treatable conditions presenting to the primary health care level would be an important accompanying message not included in the EDL.