Flaw in Alzheimer's drug trial test
New research led by Plymouth University Peninsula Schools of Medicine and Dentistry suggests that the cognitive test used in Alzheimer's drug trials is flawed.
The current standard cognitive test for the disease is the ADAS Cog. The new research, published as two studies in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, investigates the role of the test and questions its effectiveness.
The studies show that the ADAS Cog is not subtle enough to properly track changes in the early stages of Alzheimer's. This is important because data from this key stage is required to show whether or not a new drug is working. The study also showed that the modern method of "Rasch analysis" confirmed the flaw.
In their first study, the researchers examined 675 measurements from people, aged 53 to 90, with mild Alzheimer's disease across five time points – 0, six, 12, 18 and 24 months. In terms of final patient score the ADAS-cog seemed sound. But by breaking down all the data to component level, a different story emerged. A "ceiling effect" was exposed for eight out of the 11 parts of the ADAS-cog with many patients – ranging from 32 to 83 per cent - "passing" the section when in reality much greater variance between the patients almost certainly existed and needed scoring.
In the second study, the research team moved on to use the modern method of "Rasch analysis" to further test the data. This confirmed the flaw. The more sophisticated method of analysis also suggested a number of possible pathways to improvement including making parts of the ADAS-cog test more difficult as well as re-thinking the scoring structure.
As a consequence, the Plymouth-based research team is suggesting urgent changes to the ADAS Cog – and is not ruling out the need for a new test.
The study was led by Professor Jeremy Hobart. He said: "It is impossible to say precisely the extent to which the ADAS Cog's flaws have undermined the numerous clinical trials in which it has been used. It has been used, unchanged, for many years and its apparent contribution to suboptimal trials has led a number of drug companies to rethink their strategies. However, it is very clear that in its current form the ADAS Cog underestimates cognitive differences between people and changes over time. To determine if treatments, developed from painstaking years of research, work in expensive studies we need to invest in developing measurement instruments that are fit for purpose. This requires the routine use of different methods. In its current form, the ADAS Cog is not working in people with mild Alzheimer's disease."
Provided by University of Plymouth
- Vitamin B supplementation did not slow cognitive decline in patients with Alzheimer disease Oct 14, 2008 | not rated yet | 0
- New approach to fighting Alzheimer's shows potential in clinical trial Jan 07, 2010 | not rated yet | 0
- DHA 'fish oil' supplements do not seem to slow cognitive, functional decline in Alzheimer's disease Nov 02, 2010 | not rated yet | 0
- Results from trials of DHA in Alzheimer's disease and age-related cognitive decline Jul 12, 2009 | not rated yet | 0
- Study evaluates intranasal insulin therapy for adults with mild cognitive impairment or Alzheimer's Sep 12, 2011 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Dipole term in multipole expansion
2 hours ago Hi. I'm having some difficult in understanding something about the dipole term in a multipole expansion. Griffiths writes the expansion as a sum of...
Bubbles in a Pre-Boiling/Boiling pot of water
3 hours ago How is it that bubbles form on the bottom of a surface of a pot of boiling water? I think that there is probably an elementary answer to this...
Assumptions of Griffith's fracture theory
14 hours ago Any experts on Griffith's fracture theory? I am studying the subject and I am having hard time finding out if the theory is valid for all possible...
Current leading voltage or vice versa concept
15 hours ago Hello, I was wondering if there is a conceptual explanation for when current leads voltage or vice versa for capacitors or inductors with AC...
Angular Frequency of AC voltage
19 hours ago Hello, I am wondering, what is the physical interpretation of the angular frequency of AC voltage? I don't see the physicality of what the angle...
Modeling Rigid Body - Unsure about Euler angles and angular velocity
19 hours ago I'm modeling a single 3D rigid body in preparation for some more complicated modeling in order to gain a better understanding of Euler angles, the...
- More from Physics Forums - Classical Physics
More news stories
Researchers at USC have found that a class of pharmaceuticals can both prevent and treat Alzheimer's Disease in mice.
Alzheimer's disease & dementia 2 hours ago | 5 / 5 (1) | 0 |
Researchers have pinpointed a catalytic trigger for the onset of Alzheimer's disease – when the fundamental structure of a protein molecule changes to cause a chain reaction that leads to the death of neurons ...
Alzheimer's disease & dementia May 20, 2013 | 5 / 5 (3) | 0 |
A new study looking at sleep-disordered breathing (SDB) and markers for Alzheimer's disease (AD) risk in cerebrospinal fluid (CSF) and neuroimaging adds to the growing body of research linking the two.
Alzheimer's disease & dementia May 19, 2013 | 5 / 5 (3) | 0 |
The devastating effect of Alzheimer's disease on bilingual people has been thrown into focus in Canada, where the sudden loss of a second language can leave sufferers feeling like strangers in their own country.
Alzheimer's disease & dementia May 19, 2013 | not rated yet | 0
(Medical Xpress)—Working with lab mice models of multiple sclerosis (MS), UC Davis scientists have detected a novel molecular target for the design of drugs that could be safer and more effective than current FDA-approved ...
Alzheimer's disease & dementia May 17, 2013 | 5 / 5 (2) | 0 |
A drug commonly used to treat depression and anxiety may improve a stress-related heart condition in people with stable coronary heart disease, according to researchers at Duke Medicine.
40 minutes ago | not rated yet | 0 |
(HealthDay)—The overall health of Americans isn't improving much, with about six in 10 people either overweight or obese and large numbers engaging in unhealthy behaviors like smoking, heavy drinking or ...
50 minutes ago | not rated yet | 0
(HealthDay)—In 2008 to 2010, the prevalence of key health behaviors among U.S. adults varied, with about one in five adults current smokers and 62.1 percent overweight or obese, according to a report presented ...
40 minutes ago | not rated yet | 0
(HealthDay)—Factors such as increased case finding may explain why Michigan had half of the total spinal infections associated with contaminated methylprednisolone acetate in the recent fungal meningitis ...
30 minutes ago | not rated yet | 0
Early use of tracheostomy for mechanically ventilated patients not associated with improved survival
For critically ill patients receiving mechanical ventilation, early tracheostomy (within the first 4 days after admission) was not associated with an improvement in the risk of death within 30 days compared to patients who ...
40 minutes ago | not rated yet | 0
(HealthDay)—Three-quarters of public schools in the metro Atlanta area contain microbes, including bacteria indicating the presence of fecal matter, according to research published in the May 17 issue of ...
20 minutes ago | not rated yet | 0