Alzheimer's test - HealthNewsReview.org

Today researchers said they have developed a simple blood test that could help identify Alzheimer’s patients years before they have any major symptoms.

Our Review Summary

This story provided an incomplete profile about the attempts to develop a diagnostic test for a disease without known treatment – Alzheimer’s disease. It did little to help viewers understand the worth of such testing to the individual or the benefit this test, if successful, could have in terms of developing therapies for managing and treating this disease.

The real story here is to understand that diagnosis and treatment of a disease or condition are not the same thing; that the ability to diagnosis is often years ahead of ability to treat. But the story never touches that theme. Further, it is important for people to be aware that test results are not infallible and a false-positive result, where a person would be diagnosed with the condition when if fact he/she did not have the condition would be a very sad scenario. The story never addressed the issue of false positives.

Other issues:

The story didn’t quote an independent expert about the test. (it has a company spokesman and an independent expert who only talked about the subtlety of the disease – but who did not address these test results.)
The story didn’t address the fact that this study was published as a letter to Nature Medicine – what’s the significance of that for trying to draw conclusions from the findings?
The story inaccurately said this was a study of 259 blood samples. Tests were done on a much smaller number.

Criteria

Does the story adequately discuss the costs of the intervention?

Not Applicable

Potential costs not addressed. However, this is not a commercially available test or even available in most research labs so costs are very difficult to predict. But a story like this also could have touched on the whole issue of the downstream costs associated with testing everyone with some memory loss – which could be enormous – and the costs of providing what are now relatively ineffective current drug treaments.

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

Not Satisfactory

The story did not provide any means for assessing benefit of advanced knowledge about whether one were to develop Alzheimer’s disease. The enthusiasm for the test should be limited to its role as a research tool. The tone of the broadcast implied that knowing about the disease early would allow for treatment to benefit the patient when this is not the case.

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

Not Satisfactory

Two harms of treatment, difficulty getting insurance when one has a prexising condition and not wanting to know that one was going to develop this disease, were mentioned in the broadcast.

But the story never addressed the issue of false positive test results – which could be a huge issue. Imagine being told erroneously that you test positive for Alzheimers disease!

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

Not Satisfactory

The broadcast reported that in the one study, the test was 90% accurate. However it failed to provide any context that might help viewers understand what this means in terms of the proportion of individuals who were predicted to develop Alzheimer’s but didn’t or the number of people who developed Alzheimer’s without being previously predicted to do so.

They failed to describe the type of population that was studied, how representative they may or may not have been. In addition, the story stated this was a study on 259 blood samples. Rather the test was developed from these samples and tested on a rarified sample of about 50.

Finally, the story didn’t address the fact the study was published in Nature Medicine as a letter – not as an original research article. What is the significance of that for judging the quality of the evidence?

Does the story commit disease-mongering?

Not Satisfactory

The story does not exaggerate the problem and prevalence of Alzheimer’s disease. However, by repeating the mantra that an early diagnosis by a blood test is a good thing, one is led to believe that there is an intervention that may be widely applicable. (It states: "For millions who worry their forgetfulness could be the first sign of something worse, a blood test could, in the future, provide answers.") In this sense, there is disease mongering by implying many could benefit from this test when the notion of benefit is speculative at best.

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

Not Satisfactory

The story quoted someone from the company developing the test and quoted only one "expert" but he did not comment on the test but only on the subtlety of the disease. This is insufficient sourcing for a story that states: "For millions who worry their forgetfulness could be the first sign of something worse, a blood test could, in the future, provide answers."

Does the story compare the new approach with existing alternatives?

Satisfactory

The story states that "only an autopsy can establish for sure whether a patient had Alzheimer’s. Brain scans and spinal taps are helpful, but they’re not certain. But the story did not provide insight about treatment options and what one could and couldn’t do with advance information about pending development of Alzheimer’s disease.

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

Satisfactory

The report clearly states that "plenty of lab work" still remains before it’s proven that a simple blood test can diagnose Alzheimer’s. Even though this is tacked on as a disclaimer as the last sentence of an otherwise exuberant report, we’ll give it the benefit of the doubt on this criterion.

Does the story establish the true novelty of the approach?

Satisfactory

The broadcast did lay out for viewers that currently, it is only after death that Alzehimer’s disease can be definitely diagnosed and so if this test were demonstrated to be valid, it would represent something new.

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

Not Applicable

We can’t be sure if the story relied solely or largely on a news release.

Total Score: 3 of 8 Satisfactory

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