WHO to world’s nations: Make a diagnostics plan
Volume 8, Issue 1 | June 7, 2023
In This Issue
Should hospitals test incoming patients for COVID?
A postscript on RADx - A new gold standard?
Racial bias in a lung function test
Newborn genetic screening can benefit family members
New and Noteworthy
Diagnostics in the global spotlight - in a very good way
The importance of diagnostics was underscored at the 2023 World Health Assembly, with the adoption of the WHO’s statement on strengthening diagnostics capacity. It urges each of the 194 WHO member states to create its own national diagnostic strategy, emphasizing that these plans should cover regulation, workforce, data integrity, and management of diagnostics. This statement follows the lead of The Lancet’s 2021 Commission on Diagnostics, which noted that 47% of the world’s population does not have access to adequate and timely tests. Separately but very much related, the WHO/WHA statement also calls for the creation of an International Alliance for Diagnostics.
Commentary: You probably can guess what we have to say about this - hoorah! But we will still add one more comment: This is not just an issue in the developing world. When COVID first hit, we in the US and other wealthy countries were not prepared to quickly and effectively use testing to combat disease. We need to learn this lesson, too.
Benefits of newborn screening can extend to baby’s family
We know that genomic screening has benefits for newborns - new data published in Cell shows that this screening can help the baby’s family, too. In the study, 17 babies (11% of the study participants) were found to have unanticipated single-gene-based disease risks. Those results prompted family members of 13 babies to undergo genetic testing of their own - and three of those family members underwent cancer-risk-reducing surgeries after receiving their results.
Should hospitals test all admitted patients for COVID?
Such testing is no longer standard policy in US hospitals - but should it be? The primary argument against routine testing is that in-hospital mortality due to COVID has declined substantially from the 2020/21 and 2021/22 winter peaks, when it hovered around 25%, to 7% currently (see chart); COVID is now “just” one of many non/pre-symptomatic infectious diseases from which patients may be suffering on admission. The counter-arguments: COVID has a far higher rate of non/pre-symptomatic infection than other circulating diseases; hospital-acquired infections in general are a serious, ubiquitous, and unsolved problem; and hospitalized patients are more vulnerable than the population at large.
A study published in JAMA added critical evidence to the discussion, showing that after testing was formally abandoned in the UK at the end of August 2022, hospital-acquired COVID infections there exceeded those acquired in the community (see chart).
Commentary: The JAMA study is provocative evidence that COVID testing at admission should still be standard practice. Why can’t hospitals test for a panel of common hospital-acquired pathogens on admission as a way to stamp them out at the source?
Almost all in the US have some immunity to COVID
A large longitudinal study of blood donors estimated that by the summer of 2022, more than 96% of people in the US 16 years old and older had antibodies to SARS-CoV-2. Of that group, the largest subset (48%) had hybrid immunity; 26% had antibodies from vaccination alone, and 22% from infection alone.
Food for Thought
RADx Review Postscript: Time for a new gold standard - and more education
Commentary: We received a lot of feedback about our piece on RADx, most of it focused on the constraints required by the current regulatory environment. New technologies, by their very nature, often challenge the status quo - they may even prompt a re-definition of the “gold standard” against which devices in the field are measured.
In COVID diagnostics, the gold standard has historically been a sample obtained by nasopharyngeal (back of the throat) swab, analyzed by a PCR test. During the height of the pandemic there was much debate and commentary about whether the FDA should create a “screening” (or “second”) gold standard, to be used only for screening tests. By design, these technologies would not have to meet the PCR gold standard required for diagnostic tests, but would be held to a standard that made them perfectly adequate for screening purposes.
What are the arguments for this creation of this new standard? It might make non-PCR technologies more approvable. It might also accelerate the FDA review process, as comparable technologies would be compared to one another. The challenge, of course, is that the public will likely say “A test is a test,” and use a screening test as if it was a diagnostic test. (We get it, but would argue that that is already happening.)
Is it good to have standards? Absolutely. Is it good to have one standard for all tests despite different intended uses? Probably not. Given the realities on the ground, continuing education for the public and health care providers on the right test for the right time is the way forward.
If your test’s algorithm is racially biased, your results will be, too
A common medical test may be underdiagnosing lung problems in as many as 40% of Black patients, according to a recent study in JAMA Network Open. The test in question is a pulmonary function test (PFT), which measures “how much and how quickly a person can inhale and exhale,” as the Associated Press described it. The problem originates from an assumption, dating back to the 1850s, that Black people’s lungs are not as strong as white people’s lungs are. That assumption is baked into the software that clinicians use to analyze PFT results: The software expects that a Black person’s lungs won’t be able to move as much air as effectively as a white person’s lungs will. Thus, the same PFT result often triggered different diagnoses, depending on the patient’s race. In a white person, results that indicated decreased lung function (and would ostensibly trigger further workup and treatment) would, in a Black person, simply be labeled “normal.”
Commentary: As the paper points out, there is no biological justification for incorporating race into PFT interpretation - that 1850s assumption about lung function is simply wrong. (Folks, that was 170 years ago!) We echo the authors’ conclusion that, “Rather than correct for fundamental natural differences, the incorporation of racial and ethnic categories into reference equations has served to mask social, political, and economic realities under the guise of essential biology.” Diagnostics developers, check your algorithms and your baseline assumptions. Let’s get this problem fixed ASAP.
Quick Hits
Cue Health has received the FDA’s first full marketing approval for an at-home COVID test. Moving forward, we expect that there will be more of these - especially with the bolus of antigen tests currently under EUA that are likely going through the FDA system.
The FDA has authorized the first blood test to predict the risk of severe pre-eclampsia. The life-threatening hypertensive disorder is one of the most common complications of pregnancy and the postpartum period, and disproportionately affects Black women.
EUA Update
The FDA issued one new 510(k) premarket notification, three new EUAs, 14 amendments to existing EUAs, and two revocations in May. Data is available at TestingCommons.com
Late Breaking News: June 6th announcement: FDA Marketing Authorization (traditional premarket review pathway) (1): Cue COVID-19 Molecular Test
510(k) Premarket Notifications (1): Panther Fusion Sars-Cov-2/Flu A/B/Rsv Assay
New EUAs (3):
COVID Molecular (1): Access Medical Laboratories Global Direct RT-PCR Test
COVID Antigen (2): Nano-Ditech Nano-Check COVID-19 Antigen At-Home Test | BioTeke USA Bio-Self COVID-19 Antigen Home Test
Amendments to Existing EUA’s (14):
COVID Molecular: 5
COVID Collection Kits: 0
COVID Antigen: 7
Respiratory multiplex (COVID and Flu): 2
Revocations (2): Clip COVID Rapid Antigen Test | NeuMoDx Flu A-B/RSV/SARS-CoV-2 Vantage Assay