Disorientation to time can be used as a guide to determining the presence and severity of dementia. The inability to maintain one’s wrist watch at the correct time is assessed as a possible marker of dementia.
Inpatients in a post-acute care unit with a mean age of 76.2 (±12.4 years) were assessed with regard to the time on their wristwatch. The time was recorded as correct or incorrect with a permitted discrepancy of 15 minutes. A current Mini-Mental State Examination (MMSE) score was obtained and patients were divided into two groups: MMSE above/equal to or below 24, with the latter defined as an abnormal result.
The most striking finding of this study was that any patient with an incorrectly set watch had an abnormal MMSE. The majority of patients with an abnormal MMSE had their watch set correctly (38%), while only 22% were found to have an incorrectly set watch. All patients with a normal MMSE had their watch set correctly. Acknowledging the fact that conclusions of statistical methods used on a small sample size should be interpreted with caution, we report that the two-tailed Z score for 2 population proportions was 2.9277 (p=0.00338).
This study presents evidence to suggest a relationship between the correctness of the older patient’s watch and their cognitive status. Assessment of time on the patient’s watch could be considered as an instantaneous, approximate “test” for dementia in clinical practice. This test would have a sensitivity of 37% and specificity of 100%.