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Spit test for concussion detection: CNN story includes some important caveats


4 Star


Spit test may diagnose, predict duration of concussion in kids

Our Review Summary

CNN’s story describes a study that identified microRNA markers in the saliva of children and teens who’ve sustained a concussion; five of these biomarkers could be used in an algorithm to predict whether or not the youngsters’ concussions symptoms would subside within four weeks of their injury.

The story did a good job explaining the study’s limitations, and describing similar tests under development–helping readers understand this is by no means the only method that’s being studied. We were also pleased to see independent sources and disclosure of potential conflicts of interest. However, the story could have provided more information on the potential harms of screening tests, as well as expected costs.


Why This Matters

Concussions are a hot medical topic, as we explain in Communicating effectively about concussion research: 6 tips for writers. When it comes to screening tools, however, news outlets sometimes overlook the nuances. This CNN story, for example, didn’t discuss the potential downsides of false-positive and false-negative results.


Does the story adequately discuss the costs of the intervention?

Not Satisfactory

The story provides no discussion of how much this test might cost if and when it comes to market.

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

The story states that the five key microRNA markers allowed doctors to predict with 85% accuracy which 52 of the children would have prolonged symptoms, compared to 64% accuracy for the standard concussion assessment survey doctors often use now (in conjunction with their own medical evaluations).

But it’s not clear what “accuracy” means in this context. As discussed below, it would be more helpful to discuss the test’s false-negative and false-positive rates, since those statistics give readers a better sense as to whether the test results provide meaningful information.

And it would be helpful to clarify exactly what benefit someone would derive from the test results, beyond knowing how long the concussion symptoms will endure. Readers might presume that this kind of testing will help avoid longer-term cognitive impairment resulting from concussions, but that would be a misconception. There’s no evidence that more testing leads to less long-term cognitive impairment. The story would have done well to point this out.

Does the story adequately explain/quantify the harms of the intervention?

Not Satisfactory

The story does not directly address potential harms. The harms with screening tests are false-negative results–in this case, concluding a child doesn’t have a concussion when she really does–and false-positive results–concluding a child needs treatment when she doesn’t.

Does the story seem to grasp the quality of the evidence?


The story does a fair job of describing the limitations of the research supporting use of the saliva test. First, the story notes that an editorial published with the study in JAMA Pediatric pointed out the small sample size (52), meaning additional large-scale studies would be required to determine whether the saliva test results would be reliable. The story also discusses the editorial’s warning that individuals with prolonged concussion symptoms are more likely than those with milder concussions to use nonsteroidal anti-inflammatory drugs such as ibuprofen, which could influence the presence of the microRNAs and thus confound the findings.

One limitation the story didn’t point out was that all these children already had a clinical diagnosis of concussion. In a more real-world setting, where that hasn’t been confirmed, the accuracy of the test may be lowered.

Does the story commit disease-mongering?


The story does not commit disease-mongering. However, one paragraph discussing data from the Centers for Disease Control could be viewed as conflating concussions with all traumatic brain injuries (TBIs). The story notes that CDC data showed 2.8 million TBI-related visits to the emergency room, hospitalizations and deaths in the United States in 2013. Following this figure immediately is a reference to two-thirds of concussions occurring in children and adolescents; the structure thus suggests that all 2.8 million TBIs were concussions.

Does the story use independent sources and identify conflicts of interest?


The story includes two independent sources: the JAMA Pediatrics editorial and a neurologist, Dr. Jeffrey Kutcher, who directs The Sports Neurology Clinic at The CORE Institute in Michigan. In addition, the story explains that Quadrant Biosciences, which is hoping to market a saliva test for concussions, provided part of the funding for the original study. It also notes that Kutcher is consulting for a company working on an alternative approach to testing for concussion severity using electroencephalograms (EEG).

Does the story compare the new approach with existing alternatives?


As noted earlier, the story explicitly compared accuracy rates for the saliva test versus the survey tool doctors currently use. In addition, the story mentioned that researchers also are testing for concussion-related biomarkers in blood, using EEG records and “exploring functional MRI techniques to look at the metabolic function of different areas of the brain.” The story discusses all of these approaches as preliminary investigations.

Does the story establish the availability of the treatment/test/product/procedure?


The story quotes the lead author of the saliva test study as saying that many hospitals and clinics already use the technology that would be needed to assess microRNAs in saliva. This implies that the saliva test could be readily available to patients if further research confirmed the association between specific microRNAs and prolonged concussion symptoms. The story does not provide any specific discussion of how long it could take or how much further study would be needed before the saliva test would be available for use. However, the story does communicate that the saliva test is not yet available.

Does the story establish the true novelty of the approach?


As mentioned earlier, the story quotes the JAMA Pediatrics editorial that accompanied the study as saying that the saliva test “represents an advance in the science of sport-related concussions.” Thus, the test does appear to be a novel approach.

Does the story appear to rely solely or largely on a news release?


The story includes a substantial amount of information not included in the Penn State Health news release about the study.

Total Score: 7 of 10 Satisfactory


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