TY - JOUR
T1 - Dementia Screening Accuracy is Robust to Premorbid IQ Variation
T2 - Evidence from the Addenbrooke's Cognitive Examination-III and the Test of Premorbid Function
AU - Stott, Joshua
AU - Scior, Katrina
AU - Mandy, William
AU - Charlesworth, Georgina
AU - Brandt, Jason
N1 - Publisher Copyright:
© 2017 - IOS Press and the authors. All rights reserved.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2017
Y1 - 2017
N2 - Background: Scores on cognitive screening tools for dementia are associated with premorbid IQ. It has been suggested that screening scores should be adjusted accordingly. However, no study has examined whether premorbid IQ variation affects screening accuracy. Objective: To investigate whether the screening accuracy of a widely used cognitive screening tool for dementia, the Addenbrooke's cognitive examination-III (ACE-III), is improved by adjusting for premorbid IQ. Methods: 171 UK based adults (96 memory service attendees diagnosed with dementia and 75 healthy volunteers over the age of 65 without subjective memory impairments) completed the ACE-III and the Test of Premorbid Function (TOPF). The difference in screening performance between the ACE-III alone and the ACE-III adjusted for TOPF was assessed against a reference standard; the presence or absence of a diagnosis of dementia (Alzheimer's disease, vascular dementia, or others). Results: Logistic regression and receiver operating curve analyses indicated that the ACE-III has excellent screening accuracy (93 sensitivity, 94 specificity) in distinguishing those with and without a dementia diagnosis. Although ACE-III scores were associated with TOPF scores, TOPF scores may be affected by having dementia and screening accuracy was not improved by accounting for premorbid IQ, age, or years of education. Conclusion: ACE-III screening accuracy is high and screening performance is robust to variation in premorbid IQ, age, and years of education. Adjustment of ACE-III cut-offs for premorbid IQ is not recommended in clinical practice. The analytic strategy used here may be useful to assess the impact of premorbid IQ on other screening tools.
AB - Background: Scores on cognitive screening tools for dementia are associated with premorbid IQ. It has been suggested that screening scores should be adjusted accordingly. However, no study has examined whether premorbid IQ variation affects screening accuracy. Objective: To investigate whether the screening accuracy of a widely used cognitive screening tool for dementia, the Addenbrooke's cognitive examination-III (ACE-III), is improved by adjusting for premorbid IQ. Methods: 171 UK based adults (96 memory service attendees diagnosed with dementia and 75 healthy volunteers over the age of 65 without subjective memory impairments) completed the ACE-III and the Test of Premorbid Function (TOPF). The difference in screening performance between the ACE-III alone and the ACE-III adjusted for TOPF was assessed against a reference standard; the presence or absence of a diagnosis of dementia (Alzheimer's disease, vascular dementia, or others). Results: Logistic regression and receiver operating curve analyses indicated that the ACE-III has excellent screening accuracy (93 sensitivity, 94 specificity) in distinguishing those with and without a dementia diagnosis. Although ACE-III scores were associated with TOPF scores, TOPF scores may be affected by having dementia and screening accuracy was not improved by accounting for premorbid IQ, age, or years of education. Conclusion: ACE-III screening accuracy is high and screening performance is robust to variation in premorbid IQ, age, and years of education. Adjustment of ACE-III cut-offs for premorbid IQ is not recommended in clinical practice. The analytic strategy used here may be useful to assess the impact of premorbid IQ on other screening tools.
KW - Dementia
KW - neuropsychology
KW - screening
KW - sensitivity
KW - specificity
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U2 - 10.3233/JAD-161218
DO - 10.3233/JAD-161218
M3 - Article
C2 - 28372334
AN - SCOPUS:85018741517
VL - 57
SP - 1293
EP - 1302
JO - Journal of Alzheimer's Disease
JF - Journal of Alzheimer's Disease
SN - 1387-2877
IS - 4
ER -