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- Cadar, Dorina, et al.
(författare)
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Does education explain the terminal decline in the oldest-old? Evidence from two longitudinal studies of ageing
- 2015
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Ingår i: The Lancet. - 0140-6736. ; 386:Supplement 2
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- AbstractBackground Cognitive performance substantially deteriorates close to death, as postulated by the terminal decline hypothesis. However, the association between education and terminal decline remains controversial. This study investigated the role of education in terminal decline in two European longitudinal studies of oldest-old. Methods Participants were from the Newcastle 85+, UK (n=702), and Octogenarian Twins (OCTO-Twin), Sweden (n= 845). They were assessed biannually over three and five consecutive waves, respectively. In a coordinated analysis, multilevel models were used to examine the association between education and terminal decline on mini-mental state examination (MMSE), controlling for age at baseline, dementia incidence, sex, and time to death from the study entry within each cohort. Cognitive decline was modelled as a linear function of time to death in both cohorts and as a quadratic function in the OCTO-Twin study (because of longer follow-up). Education was a continuous measure (ranging from 6 to 20 years in Newcastle 85+ and 0 to 23 years in OCTO-Twin). Findings A typical British man, aged 85 at baseline, with 10 years’ education, entered the terminal phase at around 2·5 years before death, and the mean rate of decline was −1·04 MMSE points with each year closer to the time of death (SEM 0·25, p<0·0001). By contrast, a Swedish man, aged 83 years, with an average of 7 years’ education, entered the terminal phase at around 8 years from death, after which the rate of cognitive decline steepened by −1·70 points per year closer to the time of death (SEM 0·20, p<0·0001) and accelerated by −0·11 (SEM 0·01, p<0·0001). Education was positively associated with the estimated mean MMSE scores before death only in OCTO-Twin (0·43, SEM 0·15; p=0·003) and did not attenuate the rate of terminal decline in either cohort. Interpretation Decline and acceleration of this decline were detectable in both studies before death, with steeper rates of decline observed in the Swedish cohort. However, this process was not lessened by education itself. This work contributes to a better understanding of the transition from the subtle cognitive changes associated with age to those of neurological substance, and the role of education in this decline. Funding The funding sources of this work were the Alzheimer's Society (grant number 144) and the Medical Research Council (unit programme number MC_UU_12019/1).
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| 2. |
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| 3. |
- Cadar, Dorina, et al.
(författare)
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The role of cognitive reserve on terminal decline: a cross-cohort analysis from two European studies: OCTO-Twin, Sweden, and Newcastle 85+, UK.
- 2016
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Ingår i: International journal of geriatric psychiatry. - : Wiley. - 1099-1166 .- 0885-6230. ; 31:6, s. 601-610
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Tidskriftsartikel (refereegranskat)abstract
- Cognitive performance shows a marked deterioration in close proximity to death, as postulated by the terminal decline hypothesis. The effect of education on the rate of terminal decline in the oldest people (i.e. persons 85+ years) has been controversial and not entirely understood. In the current study, we investigated the rate of decline prior to death with a special focus on the role of education and socioeconomic position, in two European longitudinal studies of ageing: the Origins of Variance in the Old-Old: Octogenarian Twins (OCTO-Twin) and the Newcastle 85+ study.
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| 5. |
- Hoogendijk, Emiel O., et al.
(författare)
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Gait speed as predictor of transition into cognitive impairment: Findings from three longitudinal studies on aging
- 2020
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 129
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 The Authors Objectives: Very few studies looking at slow gait speed as early marker of cognitive decline investigated the competing risk of death. The current study examines associations between slow gait speed and transitions between cognitive states and death in later life. Methods: We performed a coordinated analysis of three longitudinal studies with 9 to 25 years of follow-up. Data were used from older adults participating in H70 (Sweden; n = 441; aged ≥70 years), InCHIANTI (Italy; n = 955; aged ≥65 years), and LASA (the Netherlands; n = 2824; aged ≥55 years). Cognitive states were distinguished using the Mini-Mental State Examination. Slow gait speed was defined as the lowest sex-specific quintile at baseline. Multistate models were performed, adjusted for age, sex and education. Results: Most effect estimates pointed in the same direction, with slow gait speed predicting forward transitions. In two cohort studies, slow gait speed predicted transitioning from mild to severe cognitive impairment (InCHIANTI: HR = 2.08, 95%CI = 1.40–3.07; LASA: HR = 1.33, 95%CI = 1.01–1.75) and transitioning from a cognitively healthy state to death (H70: HR = 3.30, 95%CI = 1.74–6.28; LASA: HR = 1.70, 95%CI = 1.30–2.21). Conclusions: Screening for slow gait speed may be useful for identifying older adults at risk of adverse outcomes such as cognitive decline and death. However, once in the stage of more advanced cognitive impairment, slow gait speed does not seem to predict transitioning to death anymore.
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| 6. |
- Piccinin, Andrea M, et al.
(författare)
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Terminal decline from within- and between-person perspectives, accounting for incident dementia.
- 2011
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Ingår i: The journals of gerontology. Series B, Psychological sciences and social sciences. - : Oxford University Press (OUP). - 1758-5368 .- 1079-5014. ; 66:4, s. 391-401
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Tidskriftsartikel (refereegranskat)abstract
- The terminal cognitive decline hypothesis has been debated for almost 50 years. This hypothesis implies a change in rate of decline within an individual. Therefore, we examine the hypothesis from a within-person perspective using a time to death chronological structure.
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| 8. |
- Robitaille, Annie, et al.
(författare)
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Latent growth models matched to research questions to answer questions about dynamics of change in multiple processes.
- 2017
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Ingår i: Journal of clinical epidemiology. - : Elsevier BV. - 1878-5921 .- 0895-4356. ; 82, s. 158-166
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Tidskriftsartikel (refereegranskat)abstract
- Given theoretical and methodological advances that propose hypothesis about change in one or multiple processes, analytical methods for longitudinal data have been developed that provide researchers with various options for analyzing change over time. In this paper, we revisit several latent growth curve models that may be considered to answer questions about repeated measures of continuous variables, which may be operationalised as time varying covariates or outcomes.To illustrate each of the models discussed and how to interpret parameter estimates, we present examples of each method discussed using cognitive and blood pressure measures from a longitudinal study of ageing, the OCTO Twin Study.Although statistical models are helpful tools to test theoretical hypotheses about the dynamics between multiple processes, the choice of model and its specification will influence results and conclusions made.
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| 9. |
- Robitaille, Annie, et al.
(författare)
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Longitudinal Mediation of Processing Speed on Age-Related Change in Memory and Fluid Intelligence.
- 2013
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Ingår i: Psychology and aging. - : American Psychological Association (APA). - 1939-1498 .- 0882-7974. ; 28:4, s. 887-901
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Tidskriftsartikel (refereegranskat)abstract
- Age-related decline in processing speed has long been considered a key driver of cognitive aging. While the majority of empirical evidence for the processing speed hypothesis has been obtained from analyses of between-person age differences, longitudinal studies provide a direct test of within-person change. Using recent developments in longitudinal mediation analysis, we examine the speed-mediation hypothesis at both the within-and between-person levels in two longitudinal studies, Longitudinal Aging Study Amsterdam (LASA) and Origins of Variance in the Oldest-Old (OCTO-Twin). We found significant within-person indirect effects of change in age, such that increasing age was related to lower speed, which in turn relates to lower performance across repeated measures on other cognitive outcomes. Although between-person indirect effects were also significant in LASA, they were not in OCTO-Twin which is not unexpected given the age homogeneous nature of the OCTO-Twin data. A more in-depth examination through measures of effect size suggests that, for the LASA study, the within-person indirect effects were small and between-person indirect effects were consistently larger. These differing magnitudes of direct and indirect effects across levels demonstrate the importance of separating between- and within-person effects in evaluating theoretical models of age-related change. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
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| 10. |
- Robitaille, Annie, et al.
(författare)
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Transitions across cognitive states and death among older adults in relation to education: A multistate survival model using data from six longitudinal studies
- 2018
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Ingår i: Alzheimer's and Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 14:4, s. 462-472
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 the Alzheimer's Association. Introduction: This study examines the role of educational attainment, an indicator of cognitive reserve, on transitions in later life between cognitive states (normal Mini-Mental State Examination (MMSE), mild MMSE impairment, and severe MMSE impairment) and death. Methods: Analysis of six international longitudinal studies was performed using a coordinated approach. Multistate survival models were used to estimate the transition patterns via different cognitive states. Life expectancies were estimated. Results: Across most studies, a higher level of education was associated with a lower risk of transitioning from normal MMSE to mild MMSE impairment but was not associated with other transitions. Those with higher levels of education and socioeconomic status had longer nonimpaired life expectancies. Discussion: This study highlights the importance of education in later life and that early life experiences can delay later compromised cognitive health. This study also demonstrates the feasibility and benefit in conducting coordinated analysis across multiple studies to validate findings.
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