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P3‐180: Validation of the memory performance index: Aggregate analysis of 38,000 subjects
Author(s) -
Shankle William R.,
Mangrola Tushar,
Chan Timothy,
Hara Junko
Publication year - 2008
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2008.05.1746
Subject(s) - recall , analysis of variance , audiology , psychology , dementia , test (biology) , clinical psychology , medicine , cognitive psychology , disease , paleontology , biology
Background: The Memory Performance Index (MPI) is a quantitative measure of the performance profile of CERAD wordlist test (CWL). It translates the pattern onto a 0-100 scale, and classifies the score into normal, borderline and impaired. To characterize the MPI’s measurement characteristics for normal aging and dementia, aggregate data analyses were performed. Methods: Community Sample A: 38,817 independently living subjects 18-100 years old were assessed with the CWL, and classified as cognitively impaired or normal. The MPI and CWL immediate, delayed and total free recall scores were each regressed against age, gender and education. Clinical Sample B: As part of a comprehensive battery, the CWL plus the Functional Assessment Staging Test (FAST) was administered to 441 normal-to-moderately severely demented patients (FAST stages 1-6. Their median MPI scores were tested for significant differences across FAST stages. Results: A total of 31,583 Sample A subjects were classified as normal. Age explained 4.7% and 3.0% of CWL immediate and delayed free recall score variance, and 43.7% of MPI score variance. Gender and education only slightly increased the variance explained. For Sample B, median MPI scores progressively declined across all FAST stages (p 0.00013) except stages 2 and 3 (p 0.15). Conclusions: In cognitively normal subjects, age, gender and education poorly predicted the numbers of words recalled during immediate or delayed recall, but predicted the pattern of recalled and non-recalled words (MPI scores) very well. Pattern of memory performance is a much better measure of normal, age-related change than number of words recalled. Also, the correlation between declining function (FAST) and MPI score from normal aging to moderately severe dementia makes the MPI useful for longitudinal monitoring of cognitively impaired and demented patients.