The AMT-4 calculator assesses cognitive function using four orientation questions related to age, date of birth, place, and year. The assessment process involves evaluating each response for accuracy, providing either a "Correct" or "Incorrect" designation. A correct answer receives a score of 1, while an incorrect answer yields 0. The responses are scored as follows:

- Age: Correct = 1, Incorrect = 0
- Date of birth: Correct = 1, Incorrect = 0
- Place: Correct = 1, Incorrect = 0
- Year: Correct = 1, Incorrect = 0

The total score, ranging from 0 to 4, is the sum of these individual scores. Based on this total, the calculator offers an interpretation of cognitive function:

- A score of 4 suggests "Normal cognition," indicating all questions were answered accurately, reflecting an intact orientation.
- Scores below 4 denote "Impaired cognition," suggesting one or more incorrect answers, which may point to issues with cognitive function or orientation.

The Abbreviated Mental Test 4 (AMT-4) is a brief cognitive screening tool used primarily in the elderly population. It is designed to quickly assess mental impairment, particularly in settings where time is limited, such as in emergency departments or primary care. The AMT-4 is a simplified version of the original Abbreviated Mental Test (AMT), which consists of 10 items. The AMT-4, as the name suggests, includes only four items, making it quicker and easier to administer. 

The clinical utility of the AMT-4 is to identify cognitive impairment, which can be indicative of conditions such as dementia or delirium. It is particularly useful in situations where a more comprehensive cognitive assessment is not feasible due to time constraints or patient condition. 

The AMT-4 is not recommended for use in patients with pre-existing cognitive impairment, as it may not accurately reflect changes in cognitive status. Additionally, it may not be suitable for use in patients with severe illness or those who are unable to communicate effectively.

Abbreviated mental test 4 (AMT-4)