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Attrition in Studie...
Attrition in Studies of Cognitive Aging
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- Josefsson, Maria, 1979- (författare)
- Umeå universitet,Statistik
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- de Luna, Xavier, Professor (preses)
- Umeå universitet,Statistiska institutionen
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- Nyberg, Lars, Professor (preses)
- Umeå universitet,Umeå centrum för funktionell hjärnavbildning (UFBI),Fysiologi,Diagnostisk radiologi
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- Lundquist, Anders, PhD (preses)
- Umeå universitet,Statistik
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- Villani, Mattias, Professor (opponent)
- Avdelningen för statistik, Institutionen för datavetenskap, Linköpings universitet
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(creator_code:org_t)
- ISBN 9789174597608
- Umeå : Umeå universitet, 2013
- Engelska 21 s.
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Serie: Statistical studies, 1100-8989 ; 47
- Relaterad länk:
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https://umu.diva-por... (primary) (Raw object)
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https://urn.kb.se/re...
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Abstract
Ämnesord
Stäng
- Longitudinal studies of cognition are preferred to cross-sectional stud- ies, since they offer a direct assessment of age-related cognitive change (within-person change). Statistical methods for analyzing age-related change are widely available. There are, however, a number of challenges accompanying such analyzes, including cohort differences, ceiling- and floor effects, and attrition. These difficulties challenge the analyst and puts stringent requirements on the statistical method being used.The objective of Paper I is to develop a classifying method to study discrepancies in age-related cognitive change. The method needs to take into account the complex issues accompanying studies of cognitive aging, and specifically work out issues related to attrition. In a second step, we aim to identify predictors explaining stability or decline in cognitive performance in relation to demographic, life-style, health-related, and genetic factors.In the second paper, which is a continuation of Paper I, we investigate brain characteristics, structural and functional, that differ between suc- cessful aging elderly and elderly with an average cognitive performance over 15-20 years.In Paper III we develop a Bayesian model to estimate the causal effect of living arrangement (living alone versus living with someone) on cog- nitive decline. The model must balance confounding variables between the two living arrangement groups as well as account for non-ignorable attrition. This is achieved by combining propensity score matching with a pattern mixture model for longitudinal data.In paper IV, the objective is to adapt and implement available impu- tation methods to longitudinal fMRI data, where some subjects are lost to follow-up. We apply these missing data methods to a real dataset, and evaluate these methods in a simulation study.
Ämnesord
- SAMHÄLLSVETENSKAP -- Annan samhällsvetenskap -- Övrig annan samhällsvetenskap (hsv//swe)
- SOCIAL SCIENCES -- Other Social Sciences -- Other Social Sciences not elsewhere specified (hsv//eng)
Nyckelord
- Attrition
- missing data
- age-related cognitive change
- non- ignorable dropout
- monotone missing pattern
- mixture models
- pattern- mixture models
- imputation
- Statistics
- statistik
Publikations- och innehållstyp
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- dok (ämneskategori)
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