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Greater Variability in Cognitive Decline in Lewy Body Dementia Compared to Alzheimer's Disease

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Greater Variability in Cognitive Decline in Lewy Body Dementia Compared to Alzheimer's Disease. / Giil, Lasse Melvaer; Aarsland, Dag.

In: Journal of Alzheimer's Disease, Vol. 73, No. 4, 01.01.2020, p. 1321-1330.

Research output: Contribution to journalArticle

Harvard

Giil, LM & Aarsland, D 2020, 'Greater Variability in Cognitive Decline in Lewy Body Dementia Compared to Alzheimer's Disease', Journal of Alzheimer's Disease, vol. 73, no. 4, pp. 1321-1330. https://doi.org/10.3233/JAD-190731

APA

Giil, L. M., & Aarsland, D. (2020). Greater Variability in Cognitive Decline in Lewy Body Dementia Compared to Alzheimer's Disease. Journal of Alzheimer's Disease, 73(4), 1321-1330. https://doi.org/10.3233/JAD-190731

Vancouver

Giil LM, Aarsland D. Greater Variability in Cognitive Decline in Lewy Body Dementia Compared to Alzheimer's Disease. Journal of Alzheimer's Disease. 2020 Jan 1;73(4):1321-1330. https://doi.org/10.3233/JAD-190731

Author

Giil, Lasse Melvaer ; Aarsland, Dag. / Greater Variability in Cognitive Decline in Lewy Body Dementia Compared to Alzheimer's Disease. In: Journal of Alzheimer's Disease. 2020 ; Vol. 73, No. 4. pp. 1321-1330.

Bibtex Download

@article{f04f6fe30028431f93b35e9b2ae45230,
title = "Greater Variability in Cognitive Decline in Lewy Body Dementia Compared to Alzheimer's Disease",
abstract = "Studies indicate more rapid cognitive decline in patients with Lewy body dementia (LBD) compared to Alzheimer's disease (AD). However, there has been less focus on any difference in the variability of cognitive decline. We assessed Mini-Mental State Examination (MMSE) test performance at baseline and annually for 5 years in 222 patients with mild dementia in the DemVest study who had either AD (137) or LBD (85). We used linear mixed models (LMMs) with random intercepts (variability in MMSE at baseline) and slopes (variability in MMSE decline), with years in study, age, gender, and diagnosis as independent variables. A non-linear (quadratic) trajectory was selected, interacting with age and diagnosis. To study differences in variance, we compared a regular LMM (i.e., a homoscedastic model), which assumes equal variance across groups, to a heteroscedastic model, assuming unequal intercept and slope variance based on diagnosis. The heteroscedastic model gave a better fit (Likelihood ratio test: χ2 = 30.3, p < 0.001), showing overall more variability in LBD. Further, the differences in intercept and slope variances were tested using a modified Wald test. The MMSE intercept variance (AD: 2.78, LBD: 7.75, difference: 4.97, p = 0.021) and slope variance (AD: 2.62, LBD 7.81, difference: 5.19, p = 0.004) were both higher in LBD. In conclusion, patients with LBD in the DemVest study have a higher variability in MMSE scores at study inclusion, and in MMSE decline compared to AD. Accordingly, clinical trials on LBD may need a larger sample size compared to AD.",
keywords = "Alzheimer's disease, cognitive decline, dementia with Lewy bodies, heteroscedastic, Lewy body dementia, Lewy body disease, MMSE decline, random effects, trajectory, variability, variance",
author = "Giil, {Lasse Melvaer} and Dag Aarsland",
year = "2020",
month = jan,
day = "1",
doi = "10.3233/JAD-190731",
language = "English",
volume = "73",
pages = "1321--1330",
journal = "JOURNAL OF ALZHEIMERS DISEASE",
issn = "1387-2877",
number = "4",

}

RIS (suitable for import to EndNote) Download

TY - JOUR

T1 - Greater Variability in Cognitive Decline in Lewy Body Dementia Compared to Alzheimer's Disease

AU - Giil, Lasse Melvaer

AU - Aarsland, Dag

PY - 2020/1/1

Y1 - 2020/1/1

N2 - Studies indicate more rapid cognitive decline in patients with Lewy body dementia (LBD) compared to Alzheimer's disease (AD). However, there has been less focus on any difference in the variability of cognitive decline. We assessed Mini-Mental State Examination (MMSE) test performance at baseline and annually for 5 years in 222 patients with mild dementia in the DemVest study who had either AD (137) or LBD (85). We used linear mixed models (LMMs) with random intercepts (variability in MMSE at baseline) and slopes (variability in MMSE decline), with years in study, age, gender, and diagnosis as independent variables. A non-linear (quadratic) trajectory was selected, interacting with age and diagnosis. To study differences in variance, we compared a regular LMM (i.e., a homoscedastic model), which assumes equal variance across groups, to a heteroscedastic model, assuming unequal intercept and slope variance based on diagnosis. The heteroscedastic model gave a better fit (Likelihood ratio test: χ2 = 30.3, p < 0.001), showing overall more variability in LBD. Further, the differences in intercept and slope variances were tested using a modified Wald test. The MMSE intercept variance (AD: 2.78, LBD: 7.75, difference: 4.97, p = 0.021) and slope variance (AD: 2.62, LBD 7.81, difference: 5.19, p = 0.004) were both higher in LBD. In conclusion, patients with LBD in the DemVest study have a higher variability in MMSE scores at study inclusion, and in MMSE decline compared to AD. Accordingly, clinical trials on LBD may need a larger sample size compared to AD.

AB - Studies indicate more rapid cognitive decline in patients with Lewy body dementia (LBD) compared to Alzheimer's disease (AD). However, there has been less focus on any difference in the variability of cognitive decline. We assessed Mini-Mental State Examination (MMSE) test performance at baseline and annually for 5 years in 222 patients with mild dementia in the DemVest study who had either AD (137) or LBD (85). We used linear mixed models (LMMs) with random intercepts (variability in MMSE at baseline) and slopes (variability in MMSE decline), with years in study, age, gender, and diagnosis as independent variables. A non-linear (quadratic) trajectory was selected, interacting with age and diagnosis. To study differences in variance, we compared a regular LMM (i.e., a homoscedastic model), which assumes equal variance across groups, to a heteroscedastic model, assuming unequal intercept and slope variance based on diagnosis. The heteroscedastic model gave a better fit (Likelihood ratio test: χ2 = 30.3, p < 0.001), showing overall more variability in LBD. Further, the differences in intercept and slope variances were tested using a modified Wald test. The MMSE intercept variance (AD: 2.78, LBD: 7.75, difference: 4.97, p = 0.021) and slope variance (AD: 2.62, LBD 7.81, difference: 5.19, p = 0.004) were both higher in LBD. In conclusion, patients with LBD in the DemVest study have a higher variability in MMSE scores at study inclusion, and in MMSE decline compared to AD. Accordingly, clinical trials on LBD may need a larger sample size compared to AD.

KW - Alzheimer's disease

KW - cognitive decline

KW - dementia with Lewy bodies

KW - heteroscedastic

KW - Lewy body dementia

KW - Lewy body disease

KW - MMSE decline

KW - random effects

KW - trajectory

KW - variability

KW - variance

UR - http://www.scopus.com/inward/record.url?scp=85080851130&partnerID=8YFLogxK

U2 - 10.3233/JAD-190731

DO - 10.3233/JAD-190731

M3 - Article

C2 - 31903991

AN - SCOPUS:85080851130

VL - 73

SP - 1321

EP - 1330

JO - JOURNAL OF ALZHEIMERS DISEASE

JF - JOURNAL OF ALZHEIMERS DISEASE

SN - 1387-2877

IS - 4

ER -

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