The Paced auditory serial addition test (PASAT): a cognitive test in MS trials

For  those of you who participate in MS clinical trials you will know how difficult it is to perform the paced auditory serial addition test (PASAT).

The PASAT is a cognitive test that requires you to concentrate, pay attention (ignore distractions), remember numbers and then add them up and try an give the correct answer. 

We use the test to assess the impact of treatments on cognition. The test is part of a battery of tests that form the MS functional composite or MSFC. 

The MSFC is another measure we use to assess disability progression or improvement in MS clinical trials. 

For example the following sequence of numbers is given every 2 or 3 seconds:

1, 6, 5, 9, 4, 9, 2, 8, .....

The answers are:

7, 11, 14, 13, 11, 10, .....

You are then given a mark based on the number of correct answers.  

You can see how it work in this online demonstration Cognitive Tests or YouTube Video Blog of an MS'er (Part 1, Part 2, Part 3)

This study assessed the difficulty of the PASAT in a population with a high level of intellectual functioning under ideal testing circumstances.

Method: One hundred medical students underwent PASAT testing. They had slept well the night before, they had eaten before the assessment, they were not using any drugs that could affect the central nervous system and they did not have depression, anxiety or any chronic disease.

Results: The average result from the three-second version of PASAT was 57.5% and, from the two-second version, it was 44.3%.

Conclusion: Even under ideal circumstances the PASAT is a very difficult test for the general population. Therefore it may not be ideal for neurologists to screen, assess and follow up MS'ers cognitive function with this test.

Brooks et al. Paced auditory serial addition test (PASAT): a very difficult test even for individuals with high intellectual capability. Arq Neuropsiquiatr. 2011 Jun;69(3):482-4.

"I couldn't agree more with the conclusions. Whenever I administer the PASAT in our trial unit I get tired for the subject being tested."

"I find these results rather surprising; may be I should test myself and see how I do in the test?"