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P4‐294: REPETITIVE PHENOMENA IS SPECIFIC FOR ALZHEIMER'S DISEASE
Author(s) -
Ong Kevin,
Woodward Michael
Publication year - 2014
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.2014.07.065
Subject(s) - memory clinic , atrophy , medicine , cognitive impairment , posterior cingulate , audiology , cognition , disease , pediatrics , psychiatry
Background: During the development and validation of neuropsychological measures for native English speakers, normative data are typically collected from healthy normal individuals across an age range (e.g. 1890 years-old) and from a specified geographic region (usually the USA). However, these norms may not be valid across geographically/culturally different populations. The purpose of this investigation was to compare, within a large Australian cohort, published norms against those derived from a, within-study, large sub-cohort of healthy individuals, as well as to examine the impact of a variety of demographic, clinical and biomarker variables on normative standards.Methods: Data from the Australian Imaging, Biomarkers and Lifestyle Study were used to compare three different normalisation procedures: (i) published population norms; (ii) norms derived from within-study participants who remained healthy over 3-years; (iii) norms derived from within-study amyloid negative (PiB-PETSUVR<1.5) participants who remained healthy over 3 years. The published norms were age, education and/or gender corrected. Multiple linear regressions were used to derive norms from within-study, with covariates including age, education, gender, premorbid IQ, and depressive symptomatology. Deviations from the raw data were assessed. Efficacy of the norms was examined cross-sectionally with receiver operating characteristics for separating a well defined HC population (3-years stable, amyloid negative) from diseased populations (AD, MCI or amyloid positive HC). Results: There was generally good alignment between the normed and raw data. Differences in the normed data were exacerbated in more diseased groups (AD>MCI>HC). There was a general, expected, increase in efficacy for stratifying more severely diseased participants (AD>MCI>amyloid positive HC). A systematic trend shows that population norms are not as effective as the within-study derived norms for differ-