Clock Drawing Test - Geriatric Primary Care

Why

The clock drawing test (CDT) has been proposed as a quick screening test for cognitive dysfunction secondary to dementia, delirium, or a range of neurological and psychiatric illnesses (Cucinotta D, 2004).

The CDK can be effectively administered to resistant and non-compliant older persons, (Freund B, 2005)

How

• Provide patient with a piece of paper with a pre-drawn circle of approximately 10 cm in diameter.

• Indicate that the circle represents the face of a clock and ask the patient to put in the numbers so that it looks like a clock.

• Ask the patient to add arms so that the clock indicates the time "ten minutes after eleven."

Scoring

The choice of a scoring system ultimately depends on the specific needs and goals of the clinician or researcher.

Score Card

The clock is divided into eighths, beginning with a line through the number 12 and the center of the circle.

If the 12 is missing, its position is assumed to be counterclockwise from the 1 at a distance equal to that between the 1 and 2.

Any straight edge may be used to divide the clock into eighths.

The scoring template shows the clock circle, already divided in to eighths.

A scoring template, drawn on a see-through sheet of plastic, is placed over the patient's drawing.

Alternatively, a scoring template drawn on paper, is placed under the patient's drawing so that the scoring template clock shows through the patient's drawing paper above it.

One point each is given for the numbers 1, 2, 4, 5, 7, 8, 10, and 11 if at least half the area of the number is in the proper octant of the circle relative to the number 12.

One point each is given for an obvious short hand pointing at the 11 and an obvious long hand pointing to the 2.

The difference in the length of the hands must be obvious at a glance.

A score of :

10 suggests that cognitive impairment (CI) is unlikely.

8 or 9 must be interpreted clinically.

<8 indicates CI

<5 indicates prominent impairment.