Today researchers said they have developed a simple blood test that could help identify Alzheimer’s patients years before they have any major symptoms.
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.
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.
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.
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!
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.
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.
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."
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.
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.
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.
We can’t be sure if the story relied solely or largely on a news release.