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Cognitive screening for elderly patients with mild dementia is typically conducted in the morning under the impression that testing at this time will optimize performance and cooperation of patients. This study was conducted to determine if the time of day in which several cognitive screening tests would be normally given could significantly affect test performance in patients with mild dementia and normal control subjects.


Fifty nursing home residents with mild to moderate dementia and twenty normal control subjects were given three commonly used cognitive tests in two separate sessions (morning and afternoon) with a two week interval between sessions. Half of subjects were tested first in the morning and second in the afternoon, the other half first in the afternoon and second in the morning. Evaluation tools included the Mini Mental Status Exam (MMSE), the Mini-Cog Test, and Semantic Verbal Fluency (for animal names) at each session. Test scores were compared within each subject between the morning and afternoon sessions.


Across all subjects, better scores were observed for afternoon performance in the MMSE score (p<0.005) and Mini-Cog (p<0.011) for subjects who tested first in the morning and second in the afternoon. No differences were observed in the reverse condition. The morning/afternoon differences and trends across all subjects were strongest for the mild dementia group (MMSE, p<0.003; Mini-Cog, p<0.075). However, the analysis also indicated that test experience contributed to some of the observed differences, such that no clear effect of time of day on performance could be substantiated.


Under the conditions of this study, we could not conclude that performance on cognitive tests was significantly affected by the time of day of administration. A more comprehensive study will be necessary to better define the potential factors identified.

Publisher's Statement

Originally published in the HSOA Journal of Alzheimer’s and Neurodegenerative Diseases, 2(1) [Article 003]. Licensed under CC BY 3.0. This material can be found here.