The next at-home STI test is here
Volume 8, Issue 21 | November 16, 2023
In This Issue
Whole-body MRI may be trendy, but. . . .
Home sample collection for first non-HIV STI test
FDA next steps on pulse-ox equity
New oncology drugs based on biomarkers
A method for better sepsis outcomes
Correction to Last Week’s Issue
The FDA has pledged that once the Section 564 Public Health Emergency is lifted, they will give companies / labs 180 days (~6 months) to file submissions for full marketing clearance for tests that are currently under EUA. We apologize for our error.
New and Noteworthy
Home sample collection for chlamydia and gonorrhea test approved
The FDA has given marketing approval for the first “at-home” chlamydia and gonorrhea test. We put “at-home” in quotes because while the person being tested can take the samples for this OTC test at home, they have to send the samples to a lab for analysis. Results are delivered online; if they’re positive or ambiguous, follow-up is recommended. This is the first test for a sexually transmitted infection (STI) other than HIV for which home sampling has been approved.
STIs are an important focus area today, as the rate of disease is growing aggressively. According to the CDC, in 2021 there were 1.6 million cases of chlamydia (a 4% increase from 2020) and 700,000 gonorrhea cases, a 28% increase since 2017.
Commentary: As important as the approval was, it is even more telling to read this comment from Jeff Shuren, director of the FDA’s Center for Devices and Radiological Health: “We are eager to continue supporting greater consumer access to diagnostic tests, which helps further our goal of bringing more health care into the home.” Given the sensitive (perceived and real) nature of these infections, we expect to see home sample collection and home testing for many more STIs coming soon.
FDA steps toward pulse-ox equity: Plan a study to figure out how to do better studies
Last week we reported that more than half the nation’s attorneys general had cosigned a letter asking the FDA to move forward more urgently to address the inaccuracy that pulse oximeters have when used on people with darker skin. This week the agency published their next steps: A “discussion paper” and plans for a virtual public meeting on the topic on February 2, 2024.
The paper lays out the design of a clinical study intended to figure out the best way to improve clinical studies of pulse oximeters. It ends with a series of questions the agency is looking to answer, including: Which pigmentation scale should studies use? Do studies need to consider both race/ethnicity and pigmentation, or just pigmentation? The paper is open for public comment until January 16, 2024.
FDA approves oncology drugs based on biomarkers
The FDA approves new drugs for cancer patients - not new. What’s still relatively unusual, but increasing, is that the use of these drugs is based on the presence of biomarkers. For non-small-cell lung cancer, it’s a ROS-1 positive mutation. For patients with HR+ / HER2- breast cancer, it’s one or more PIK3CA / AKT1 / PTEN mutations. (For the breast-cancer drug, the FDA specifically mentions that these mutations should be detected by an FDA-approved test.)
Commentary: Why is this relevant to diagnostics? Well, unless the physician has spiffy x-ray vision that allows them to visualize a patient’s genomic profile, the only way to tell whether a patient has one of these mutations is through a genomic test of the patient / patient’s tumor. We hope and expect more drugs to be approved with the requirement that a specific biomarker is present or absent.
Food for Thought
If “all the cool kids are getting full-body MRIs,” should you?
We are generally skeptical about screening asymptomatic, healthy individuals absent known risk factors. Most tests are insufficiently sensitive to catch the most worrisome conditions early enough to make any difference to health outcomes, and false-positive rates make the predictive value of a positive quite low.
The current “screen-du-jour” is the whole-body MRI, being marketed aggressively by spa-like private-sector radiology centers - and it has those exact problems. No national or professional bodies recommend this type of screening (in fact, most recommend against it), and despite emotionally worded anecdotes about individual lives saved, there is no clinical trial data that supports it. By contrast, a 2019 meta-study found that of the 12.6% of patients who received a positive report from such screening, 16% were false, leaving 84% as true positives. None of the underlying studies evaluated cases missed (false negatives).
Commentary: The potential harm of a whole-body MRI is relatively low, but the test is time-consuming, expensive, not covered by insurance, and provides limited value. Meanwhile, recommended screening tests for breast, colon, cervical, and lung cancers are highly valuable, but they remain underused. Our recommendation: Make sure you are up to date with recommended screenings before even considering an expensive MRI “fishing expedition.” (See Quick Hits for another test we definitely don’t recommend.)
AI + Nurses = Better Sepsis Outcomes
We’ve written before on the challenge of diagnosing sepsis (most recently here), so it was good to see news of a program that makes a real dent in addressing it. A recent article in the Colorado Sun covered UCHealth’s method, which starts with AI-generated alerts from Epic, the electronic health record software they use. But that’s just the start.
Instead of sending those alerts directly to overworked bedside staff, UCHealth sends them to its Virtual Health Center. As the Sun reported, “When an alert pings, a nurse can pull up more information on the patient, check their chart, even look into their room via a remote camera.” If the nurse decides an alert is worth paying attention to, they can contact bedside staff or even activate a special team if needed.
The result? A two-hour improvement in time-to-identification for sepsis (each hour of delay in diagnosis = 10% increase in mortality rate), which translates to an estimated 375 people saved per year.
Quick Hits
We usually highlight effective tests and how they can increase standard of care, but thanks to ProPublica, we learned about an ineffective test that we need to highlight - because it’s still being used. When a newborn dies under suspicious circumstances, some medical examiners check to see if the infant’s lungs float in water. If they do, it supposedly means that the child was born alive (despite the fact that scientists have known since the 19th century that this “lung float test” is unreliable). The test continues to be used to help convict women of infanticide, even in the 21st century.
Correction to Last Week’s Issue
The FDA has pledged that once the Section 564 Public Health Emergency is lifted, they will give companies / labs 180 days (~6 months) to file submissions for full marketing clearance for tests that are currently under EUA. We apologize for our error.