Prose recall in dementia. A comparison of delay intervals

OBJECTIVE: To explore one methodological variation, delay length, that may contribute to contradictory findings in the literature regarding the use of delayed recall in the detection of early-stage dementia of the Alzheimer type. DESIGN: Comparison of participants with dementia and without dementia on a prose recall task at both 10- and 30-minute delay intervals. SETTING: Washington University Alzheimer's Disease Research Center, St Louis, Mo. PARTICIPANTS: Participants with very mild dementia of the Alzheimer type (n = 136) and uncompromised elderly individuals (n = 197). MAIN OUTCOME MEASURES: Results of the Logical Memory subtest from the Wechsler Memory Scale with immediate recall and 10- and 30-minute delayed recall. RESULTS: Participants with dementia recalled significantly less material than elderly controls at both immediate and delayed recall (P < .001). Multiple regression analyses revealed that dementia classification failed to account for additional variance in the 30-minute delayed score beyond that which could be accounted for by the immediate score. A small but significant proportion of variance was accounted for in the 10-minute delayed score beyond that which could be accounted for by the immediate recall score. CONCLUSION: Delayed recall of a prose passage does not appear to enhance the differentiation of very mild dementia of the Alzheimer type from normal aging in a meaningful way, whether the recall delay is 10 or 30 minutes.