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How To Measure Cognitive Decline In Older Patients

June 9, 2022Neelem Sheikh

Primary care practitioners are often the first to address a patient’s or family’s concerns about memory loss or the possibility of dementia. Detecting cognitive decline as early as possible is fundamental to a patient’s ability to receive earlier access to treatments and therapies, and, consequently, more effective treatment and improved health outcomes.

There are several assessments available to measure cognitive decline—each with its own strengths and shortcomings. Below, we provide guidance on how to measure cognitive decline in older patients, including general information on how cognitive testing works, an overview of common cognitive assessment tools, and the strengths and limitations of such assessments.

What Is Cognitive Testing?

Cognitive testing is often used by healthcare providers to detect changes in cognitive function and screen for Mild Cognitive Impairment. Of course, it is important to understand that not all changes in cognitive function are indicative of the presence of Alzheimer’s or other causes of dementia. It is possible to have cognitive changes, such as memory loss, but not dementia. 

Cognitive tests typically assess aspects of cognition such as those listed below:

  • Memory 
  • Orientation
  • Attention
  • Visuospatial abilities
  • Language 
  • Judgment
  • Ability to learn new things

There are several types of cognitive assessments, but generally, these assessments will require the patient to answer a series of questions and/or complete simple tasks.

How To Measure Cognitive Decline in Older Patients

To measure a decline in cognitive function, it is necessary to regularly and frequently assess brain function over time. By tracking trends and patterns in assessment scores longitudinally, changes in cognition can be identified.

Three of the most common tools utilized to measure cognitive decline are the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the Mini-Cog, and the general practitioner assessment of cognition (GPCOG). Here is a look at how each of these assessments works.


The MMSE is scored on a 30-point scale and takes roughly five to 10 minutes to administer. This assessment asks the patient to state the current date, count backward, and identify everyday objects. 

According to the Alzheimer’s Association, score ranges on both the MMSE and the MoCA may indicate the following:

  • Mild dementia: score of 20-24
  • Severe dementia: score of 13-20


The MoCA, also scored on a 30-point scale, takes 10 to 15 minutes to administer and includes the same aspects of the MMSE, with the addition of the following two tasks:

  • The Clock Drawing Test (CDT): The patient is tasked with drawing a clock, placing the numbers in their proper locations, then “setting” the clock to a specific time.
  • The Trail Making Test: In this two-part test, the patient must first connect 25 numbered circles, starting with one and ending at 25, as quickly as possible while maintaining accuracy. In the next part of the test, the patient must connect 25 numbered and lettered circles, alternating between numbers and letters. In other words, the path is to be traced following the pattern “1-A-2-B-3-C-4-D” and so on.


The Mini-Cog takes roughly three minutes to complete. This test consists of three steps:

  1. The patient is asked to remember three words.
  2. The patient completes the CDT.
  3. The patient must then recall and state the three words from before the CDT. 

The patient receives up to three points for word recall and up to two points on the CDT, with a maximum score of five points. A score of three, four, or five indicates a lower likelihood of dementia but does not rule out cognitive impairment. 


The GPCOG is another screening tool used to measure cognitive decline and takes between two and five minutes to administer. It is separated into two steps, with the first step being scored on a nine-point scale and the second step being scored on a six-point scale.

Step One:

Step one of the GPCOG includes five tasks:

  1. The patient is asked to remember a name and address to recall at a later time (in task five).
  2. The patient is asked to state the date.
  3. The patient completes the CDT.
  4. The patient is asked to talk about something that has happened in the news recently.
  5. The patient is tasked with recalling the name and address from task one.

If the patient scores nine, this means no significant cognitive impairment is indicated and no further testing is necessary. If the patient scores between five and eight, testing proceeds to step two. If the patient scores between zero and four, cognitive impairment is indicated.

Step Two:

In step two, the patient’s informant is asked a series of questions about the patient’s day-to-day function compared to a few years ago. If the patient scores between zero and three, cognitive impairment is indicated.

*Note: While the administration time for the above assessments may be brief, the clinical waiting time—as well as the analysis and results reporting time—can make this process rather inefficient.

Advantages and Limitations of Cognitive Assessment Tools

Each of the assessments above has its unique strengths and shortcomings regarding the thoroughness, accuracy, and validity of the assessment design. According to the Alzheimer’s Association, these are the key advantages and limitations of each assessment:

Cognitive Assessment Tool Advantages Limitations
  • Most widely used and studied worldwide
  • Often used as reference for comparative evaluations of other assessments
  • Required for some drug insurance reimbursements
  • Education, age, language, and cultural bias
  • Highly educated, yet still cognitively impaired, subjects may pass this assessment (the ceiling effect)
  • Proprietary
  • Best performance for at least moderate cognitive impairment
    • Designed to test for Mild Cognitive Impairment
    • Accessible in multiple languages
    • Tests many separate domains
    • Lack of studies in general practice settings
    • Education bias (≤12 years)
    • Limited use and evidence due to published data being relatively new
    • Developed for and validated in primary care and multiple languages and cultures
    • Little or no education/language/race bias
    • Short administration time
    • Use of different word lists may affect failure rates
    • Some study results based on longer tests with the Mini-Cog elements are reviewed independently
    • Developed for and validated in primary care
    • Little or no education bias
    • Accessible in multiple languages
    • Patient component scoring has indeterminate range that requires an informant score to assess as pass or fail
    • Lacks data on any language and cultural biases

    Addressing the Limitations of Traditional Cognitive Assessment Tools

    Many of the above assessments are purely cognitive batteries that only assess a small subset of neurocognitive domains. These assessments are not ecologically valid, meaning the design of the evaluation does not align with neurocognitive states representative of Activities of Daily Living (ADLs). Because of these limitations, such assessments often produce noisy, highly variable results that lack the specificity and granularity to adequately measure cognitive function and track cognitive decline over time.

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