Age

Attention, processing speed, memory, and conceptual reasoning gradually decline with normal aging. Semantic knowledge can improve with age. It is preferable to ensure that the measure has been validated in the patient’s age group (eg, MoCA has been validated for ages 55-85, but there are age-adjusted norms across ages 18-99).

Level of education and literacy

Cognitive screening tools can underestimate the abilities of a patient with limited education or miss subtle cognitive impairment in those with a high level of education. Level of education is often seen as a simple proxy for premorbid cognitive ability. However, many people do not have the opportunity to access education regardless of their aptitude and education benefits cognitive performance over and above baseline ability.

Language

Testing in a nondominant language can underestimate cognitive performance even if the person appears to be relatively fluent. Commonly used screening measures are usually available in a number of different languages (eg, MoCA is available in nearly 100 languages).

Culture

Clinicians are encouraged to consider relevant cultural factors when selecting bedside cognitive screeners. Certain items and constructs can vary in validity across cultures. Studies across cultures yield variable levels of validity, sensitivity, and specificity for both the MMSE and MoCA.

Comorbid conditions

Visual impairment: A viable measure is the MoCA Blind, which has good sensitivity and specificity for detecting dementia. The Telephone MMSE lacks sensitivity.

Hearing impairment: There is a version of the MoCA available for patients with severe hearing impairment (HI-MoCA).

Intellectual disability: A patient with an intellectual disability or developmental disorder could score in the impaired range on a cognitive screening tool at baseline, so a careful history should be taken to clarify whether there has been a cognitive or functional decline.

Psychiatric disorders: Patients with psychiatric disorders score lower than healthy controls on cognitive screening measures. Failure to consider the impact of psychiatric conditions on cognitive screening scores could result in misdiagnosis of MCI or dementia and delay patient access to appropriate mental health treatment.