What Is the Alzheimer’s Disease Assessment Scale Cognitive SubScale (ADAS-Cog)?

By on October 9, 2013
Alzheimer's Disease Assessment Scale Cognitive SubScale

The Alzheimer’s Disease Assessment Scale-Cognitive Subscale test is one of the most frequently used tests to measure an individuals cognitive, or thinking abilities, status while participating in clinical trials. It provides a more thorough assessment than the Mini Mental State Exam, and it primarily measures language and memory abilities. The  The Alzheimer’s Disease Assessment Scale-Cognitive Subscale test consists of 11 different parts and takes approximately 30 minutes to administer.

The  original Alzheimer’s Disease Assessment Scale-Cognitive Subscale test was developed to assess different abilities: one part measured the thinking abilities and one part that measured non-thinking abilities, such as mood and behavior. The most current clinical researcher use the ADAS-Cog, which is the sub-scale that measures just the thinking ability of the client.

When Was the The Alzheimer’s Disease Assessment Scale-Cognitive Subscale test Developed?

The Alzheimer’s Disease Assessment Scale was first published in 1984. Researchers  at that time noted that there was not a good way to clearly measure the amount of cognitive impairment in the research participants. There were other scales and assessments that determined if there was a deficiency in the thinking processes, but  there were none that consistently and accurately identified how much deterioration or changes occurred by the disease process.

What Kinds of Questions Does the Alzheimer’s Disease Assessment Scale Cognitive SubScale Contain?
The original version of the ADAS-Cog consists of 11 items, including:.
Word Recall – The person is given three chances to recall as many words as possible from a list of ten words that they were shown.

 Naming Objects and Fingers Several real objects are shown to the individual, such as a flower, pencil and a comb, and she is asked to name them. She then is asked to state the name of each of the fingers on the hand, such as pinky, thumb, etc.

Following Commands  The test-taker is asked to follow a series of sometimes multi-step but simple directions, such as, “Make a fist” and “Place the pencil on top of the card.”.

Medical exam Constructional (Drawing Abilities) Praxis – This task involves showing the person four different shapes, progressively more difficult such as overlapping rectangles, and asking them to draw each one.
Ideational( Thinking process)  Praxis- In this section, the test administrator asks the person to pretend he has written a letter to himself, fold it, place it in the envelop, seal the envelop, address it and demonstrate where to place the stamp.

Orientation -The person’s orientation is measured by asking him what his last and first name are, the day of the week, date, month, year, season, time of day, and location.

Word Recognition  In this section, the participant is asked to read and try to remember a list of twelve words. The client is  presented with those words along with several other words and asked if each word is one that she saw earlier or not.

Remembering Test Directions The individual’s ability to remember directions without reminders or with a limited amount of reminders is assessed.

 Spoken Language –The ability to make use language to make herself understood is evaluated throughout the test.

 Comprehension- The person’s ability to understand words and language over the course of the test is assessed by the test administrator.

Word-Finding Difficulty -Throughout the test, the test administrator assesses the word-finding ability throughout spontaneous conversation.

What Does the Alzheimer’s Disease Assessment Scale Cognitive SubScale Assess?

The Alzheimer’s Disease Assessment Scale Cognitive SubScale helps evaluate thinking processes and differentiates between normal thinking processes and impaired thinking functioning. It is especially useful for determining the extent of  decline of the thinking processes and can help evaluate which stage of dementia a person is in, based on the answers and score. The Alzheimer’s Disease Assessment Scale Cognitive SubScale  is often used in clinical trials because it can determine incremental improvements or declines in thinking processes of the client.

How Is the  Alzheimer’s Disease Assessment Scale Cognitive SubScale scored?

Points for each section of the Alzheimer’s Disease Assessment Scale Cognitive SubScale  are added up for a for a total score. The greater the dysfunction in thinking , the greater the score.

A normal score for someone who does not have Alzheimer’s or another type of dementia is five.  This is according to research conducted in 2004 and published in the journal Alzheimer’s Disease and Associated Disorders.

How Is the Alzheimer’s Disease Assessment Scale Cognitive SubScale  Administered?

Traditionally, the Alzheimer’s Disease Assessment Scale Cognitive SubScale has been administered by paper and pencil; however, there is also a computerized version used.

How Effective Is the Alzheimer’s Disease Assessment Scale Cognitive SubScale  in Measuring Cognitive Functioning?

The Alzheimer’s Disease Assessment Scale Cognitive SubScale has been found to be quite accurate, both in differentiating people with normal thinking processes from those with impaired thinking. It is also accurate in assessing the extent of decline in the thinking abilities in individuals.

Other tests:

Mini Mental Status Exam 

Cognitive Abilities ScreeningTest (CASI)

Pros and Cons of Dementia Testing