Review question:

What is the diagnostic accuracy of the Mini-Cog for determining Alzheimer’s disease and other dementias in a community setting?

Nursing Implications:

When caring for older adults in the community setting, nurses may detect or be told about memory impairments. In this circumstance, the administration of a brief and accurate screening test that indicates a referral for a diagnosis of Alzheimer’s disease or other dementias is timely and important. An early diagnosis allows time for the affected person and significant others to organise their affairs while they have the cognitive capacity to do so. Additionally, a diagnosis may be required for access to specialised dementia services and resources as well as medications such as the cholinesterase inhibitors that may delay the progression of Alzheimer’s disease.

The Mini-Cog is a brief cognitive screening test that consists of a delayed three-word recall and a clock drawing test. It was developed for the community care setting, takes three to five minutes to complete, and education or language do not seem to importantly influence test results.

Review Characteristics:

When caring for older adults in the community setting, nurses may detect or be told about memory impairments. In this circumstance, the administration of a brief and accurate screening test that indicates a referral for a diagnosis of Alzheimer’s disease or other dementias is timely and important. An early diagnosis allows time for the affected person and significant others to organise their affairs while they have the cognitive capacity to do so. Additionally, a diagnosis may be required for access to specialised dementia services and resources as well as medications such as the cholinesterase inhibitors that may delay the progression of Alzheimer’s disease.

The Mini-Cog is a brief cognitive screening test that consists of a delayed three-word recall and a clock drawing test. It was developed for the community care setting, takes three to five minutes to complete, and education or language do not seem to importantly influence test results.

Summary of Key Evidence:

The sensitivities of the Mini-Cog in the three studies were reported as 0.99 (95% confidence interval (CI) 0.96 to 1.00, n=249), 0.76 (95% CI 0.65 to 0.85, n=1119), and 0.99 (95% CI 0.95 to 1.00, n=252). The specificities of the Mini-Cog were reported as 0.93, 0.89, and 0.83. The relatively high sensitivity and specificity scores in two of the studies may have been influenced by a methodological limitation whereby participants with mild cognitive impairment or possible dementia were excluded from the study populations. Therefore, the accuracy of the Mini-Cog for diagnosing mild dementia is unknown at this time, although it would be anticipated that the use of the Mini-Cog for detecting mild dementia would be less accurate when compared to more advanced dementia. A meta-analysis of the diagnostic test accuracy of the Mini-Cog was not performed due to clinical and methodological heterogeneity between included studies.

Best Practice Recommendations:

It was not possible to determine whether or not the Mini-Cog can accurately diagnose mild Alzheimer’s disease and other dementias in a community setting. Nurses may prefer to use more complex tests in the community settings. However, it is worth keeping in mind the strengths of the Mini-Cog when in situations where there are no other screening tests at hand. The Mini-Cog requires limited time and resources and it may be a useful indicator for further cognitive tests and investigations of Alzheimer’s disease and other dementias.

Summary Author

Christine Neville, PhD, RN, FACMHN
Associate Professor
The University of Queensland, School of Nursing, Midwifery and Social Work