Validity of the five-word test for the evaluation of verbal episodic memory and dementia in a memory clinic setting

摘要

Background: The five-word test (FWT) uses semantic clues to optimize the encoding and retrieval of 5 items. Our objective was to assess the validity of the FWT as a measure of episodic memory when compared with the Free and Cued Selective Reminding Test (FCSRT), and its ability to distinguish participants with any dementia and especially Alzheimer disease (AD) from those with only subjective complaints. Methods: Two hundred participants with Mini-Mental State Examination (MMSE) >15 were prospectively evaluated. The sum of the immediate and delayed free recalls of the FWT is called the free recall score (FRS). The sum of the immediate free, immediate cued, delayed free, and delayed cued recalls is called the total recall score (TRS). A total weighted score (TWS) is calculated using this formula: (free recalls x 2) + cued recalls. Results: The correlation between FRS and the free recall scores of the FCSRT and between TRS and the total recall scores of the FCSRT was significant (rs ranges from.74-.84, P <.001). Area under the receiver-operating characteristic (ROC) curves of the MMSE, FRS, TRS, and TWS were not statistically different. A TWS at a cutoff value ≤15 could discriminate any dementia from subjective complaints with a sensitivity of 75% and a specificity of 95.9% or AD from subjective complaints with a sensitivity of 90.2% and a specificity of 95.9%. Conclusion: The FWT is a valid test of verbal episodic memory. It is useful to discriminate dementia especially AD from isolated subjective complaints.