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Pilot study on cerebral palsy blood test heralded as ‘breakthrough’ and ‘game changer’

Blood test predicts spastic cerebral palsy

Our Review Summary

This release focuses on a small study (22 children with spastic cerebral palsy and 21 controls) that examined whether a new method for sequencing blood samples might be a way of identifying people with cerebral palsy (CP) earlier than the methods used now.

The work centers on the early findings of differences in methylation sequences in the DNA that might point out patients with the disease.  The proposed method of genetic testing is still comparatively expensive and the release makes no mention of costs.  The release gives very little numerical data on the outcomes of the research and neglects to address the harm that might arise from false negatives and false positives, even though the release points out the diagnostic accuracy was only 73% in a pilot study involving younger children. This means at least one in four results were wrong.  The release applies the term “breakthrough” in its headline, when it clearly is no such thing, and states unequivocally in the lead that the test works, although it is far too early to make such claims.

 

Why This Matters

Cerebral palsy is a devastating condition both for patients and their families. Patients are currently diagnosed as toddlers when they begin developing motor problems.  There is currently no diagnostic test that can identify patients at earlier ages. The annual health care costs for a patient with CP, according to the release, is “10 to 26 times higher than for those without CP,” making this a costly public health problem.  If a blood test were available to identify patients soon after birth, it may allow for earlier intervention and ultimately, better outcomes.  But the work explained by the release is much too preliminary to lay claim to that solution.

Although earlier detection of CP would almost certainly drive more interventions/consultations, it is less clear that these interventions would actually lead to better outcomes. If the findings are so subtle that they are not evident on exam or by developmental milestones in early life, then it is not clear that an intervention (aggressive PT or early surgery, as suggested in the “pull out quote” in the news release) would be beneficial. Therefore, it is possible that “early detection” would simply increase costs, and possibly, parental anxiety, in the long run.

 

Criteria

Does the news release adequately discuss the costs of the intervention?

Not Satisfactory

There is no mention of the cost of this proposed diagnostic approach anywhere in the release. The entire approach to the claims made in this release relies on next generation sequencing of blood samples which can run into hundreds and sometimes thousands of dollars. The research paper points out that the approach relies on the use of parallel computing facilities, a highly expensive capability for many medical centers.

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

Not Satisfactory

The release doesn’t provide much numerical context to tell us how this test would benefit patients. It does state that the test predicted with 73% accuracy whether a blood sample came from a child with CP. This phrasing could be misleading to readers since 73% accuracy means that just over one-in-four of the samples was wrong.

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

There is no mention of potential harms that might arise from the use of such a test. A blood draw is a low risk procedure; the real potential harm comes from over- or under-diagnosis and that should have been clarified.

Does the news release seem to grasp the quality of the evidence?

Not Satisfactory

The release doesn’t tell us how many samples were analyzed in the studies. It also relies on “a strong set of methylation markers, or patterns, that indicate differences in the genome between children with spastic CP and those without it” as an indication of the likelihood of CP. It doesn’t offer readers any details on what the differences were between children with CP and controls, or how they were measured.

Does the news release commit disease-mongering?

Satisfactory

The release doesn’t engage in disease mongering. It provides some context about the disease, including its prevalence.

Does the news release identify funding sources & disclose conflicts of interest?

Satisfactory

The release names the various funding sources for this work and is clear in pointing out the commercial role, and potential economic benefit, to some of the authors.

Does the news release compare the new approach with existing alternatives?

Satisfactory

The release mentions that currently, cerebral palsy patients are identified “by monitoring motor milestones.”  It says also that there is currently no blood test available to identify CP patients younger that about two years old.

Does the news release establish the availability of the treatment/test/product/procedure?

Satisfactory

This was a small pilot study and the release states, “Many issues will need to be addressed, but we predict routine screening for CP in the near (<10 years) future.”  While many may differ with whether the “near future” is define by “fewer than 10 years,” the release gets credit for spelling this out.

Does the news release establish the true novelty of the approach?

Not Satisfactory

The release states there is no established diagnostic blood test for identifying cerebral palsy patients but it’s too early to claim that this test, still under development, is the novel “game changer” to fill that need.

Does the news release include unjustifiable, sensational language, including in the quotes of researchers?

Not Satisfactory

The release is premature in claiming the test is a “breakthrough” in the sub-headline and a “game changer” in the lead researcher’s quote.

Total Score: 4 of 10 Satisfactory

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