Distinguishing Preterminal and Terminal Cognitive Decline
Abstract
This paper reviews different methodological approaches taken to examine terminal decline in cognitive function, and presents new findings from the Bronx Aging Study (BAS). Numerous approaches have been taken to assess mortality effects on cognition: comparing survivors and decedents level and rate of change in cognition, and identifying individual differences in cognition associated with time-to-death. However, few studies have actually modeled within-person change in cognition as a function of time-to-death. Using linear mixed models with a change point, intraindividual change in episodic memory was modeled as a function of both age and time-to-death. A dramatic increase in the rate of decline was identified at 8.4 years prior to death, providing clear evidence of a terminal-decline phase that is much longer than previously estimated. These results emphasize the importance of modeling the time course and effects of terminal cognitive decline for understanding cognitive change in aging adults.
References
Akaike, H. (1973). Information theory and an extension of the maximum likelihood principle. In B.N. Petrov & F. Csaki (Eds.), Proceedings of the Second International Symposium on Information Theory (pp. 267-281). Budapest: Akademiai KiadoBaltes, P.B. , Nesselroade, J.R. (1979). History and rationale of longitudinal research. In J.R. Nesselroade & P.B. Baltes (Eds.), Longitudinal research in the study of behavior and development (pp. 1-39). New York: Academic PressBosworth, H.B. , Schaie, K.W. (1999). Survival effects in cognitive function, cognitive style, and sociodemographic variables. Experimental Aging Research, 25, 121– 140Bosworth, H.B. , Schaie, K.W. , Willis, S.L. (1999). Cognitive and sociodemographic risk factors for mortality in the Seattle Longitudinal Study. The Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 54, 273– 282Bosworth, H.B. , Schaie, K.W. , Willis, S.L. , Siegler, I.C. (1999). Age and distance to death in the Seattle Longitudinal Study. Research on Aging, 21, 723– 738Buschke, H. (1973). Selective reminding for analysis of memory and learning. Journal of Verbal Learning and Verbal Behavior, 12, 543– 550Cooney, T.M. , Schaie, K.W. , Willis, S.L. (1988). The relationship between prior functioning on cognitive and personality variables and subject attrition in longitudinal research. Journal of Gerontology, 43, 12– 17Deary, I.J. , Der, G. (2005). Reaction time explains IQ's association with death. Psychological Science, 16, 64– 69Deary, I.J. , Whiteman, M.C. , Starr, J.M. , Whalley, L.J. , Fox, H.C. (2004). The impact of childhood intelligence on later life: Following up the Scottish mental surveys of 1932 and 1947. Journal of Personality and Social Psychology, 86, 130– 147Hall, C.B. , Lipton, R.B. , Sliwinski, M. , Stewart, W.F. (2000). A change-point model for estimating the onset of cognitive decline in preclinical Alzheimer's disease. Statistics in Medicine, 19, 1555– 1566Hassing, L.B. , Small, B.J. , von Strauss, E. , Fratiglioni, L. , Bäckman, L. (2002). Mortality-related differences and changes in episodic memory among the oldest old: Evidence from a population-based sample of nonagenarians. Aging, Neuropsychology, and Cognition, 9, 11– 20Houx, P.J. , Vreeling, F.W. , Jolles, J. (1992). Usual and successful cognitive aging and health factors. International Journal of Psychology, 27, 389– 406Johansson, B. , Hofer, S.M. , Allaire, J.C. , Maldonado-Molina, M.M. , Berg, S. , Pederson, N. , McClearn, G. (2004). Changes in cognitive capabilities in the oldest-old: The effects of proximity to death in genetically-related individuals over a 6-year period. Psychology and Aging, 19, 145– 156Johansson, B. , Zarit, S.H. (1997). Early cognitive markers of the incidence of dementia and mortality: A longitudinal population-based study of the oldest old. International Journal of Geriatric Psychology, 12, 53– 59Jolles, J. , Houx, P.J. , Vreeling, F.W. , Bohnen, N. , Reyerson van Buuren, E.J. (1990). Biological risk factors for accelerated cognitive aging and dementia: Findings from a multiple cohort study. Neurobiology of Aging, 11, 293– 295Katzman, R. , Terry, R. , DeTeresa, R. , Brown, T. , Davies, P. , Fuld, P. , et al. (1988). Clinical, pathological, and neurochemical changes in dementia: A subgroup with preserved mental status and numerous neocortical placques. Annals of Neurology, 23, 138– 144Kleemeier, R.W. (1962). Intellectual changes in the senium. Proceedings of the American Statistical Association, 1, 290– 295Kleigel, M. , Moor, C. , Rott, C. (2004). Cognitive status and development in the oldest old: A longitudinal analysis from the Heidelberg Centenarian Study. Archives of Gerontology and Geriatrics, 39, 143– 156Neale, R. , Brayne, C. , Johnson, A.L. (2001). Cognition and survival: An exploration in a large multicenter study of the population aged 65 years and over. International Journal of Epidemiology, 30, 1383– 1388Rabbitt, P. , Lunn, M. , Wong, D. (2005). Neglect of dropout underestimates effects of death in longitudinal studies. The Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 60, 106– 109Rabbitt, P. , Watson, P. , Donlan, C. , McInnes, L. , Horan, M. , Pendelton, N. , Clague, J. (2002). Effects of death within 11 years of cognitive performance in old age. Psychology and Aging, 17, 468– 481Raudenbush, S.W. , Bryk, A.S. (2002). Hierarchical linear models: Applications and data analysis methods (2nd ed.). Thousand Oaks, CA: SageRiegel, K.F. , Riegel, R.M. (1972). Development, drop, and death. Developmental Psychology, 6, 306– 319Riegel, K.F. , Riegel, R.M. , Meyer, G. (1967). A study of the dropout rates in longitudinal research on aging and the prediction of death. Journal of Personality and Social Psychology, 5, 342– 348Sliwinski, M. , Lipton, R.B. , Buschke, H. , Stewart, W. (1996). The effects of preclinical dementia on estimates of normal cognitive functioning in aging. The Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 51, 217– 225Sliwinski, M.J. , Hofer, S.M. , Hall, C. , Buschke, H. , Lipton, R.B. (2003). Modeling memory decline in older adults: The importance of preclinical dementia, attrition, and chronological age. Psychology and Aging, 18, 658– 671Small, B.J. , Bäckman, L. (1999). Time to death and cognitive performance. Current Directions in Psychological Science, 8, 168– 172Small, B.J. , Fratiglioni, L. , Vitanen, M. , Winblad, B. , Bäckman, L. (2000). The course of cognitive impairment in preclinical Alzheimer disease: 3- and 6-year follow-up of a population-based sample. Archives of Neurology, 57, 839– 844Small, B.J. , Fratiglioni, L. , von Strauss, E. , Bäckman, L. (2003). Terminal decline and cognitive performance in very old age: Does cause of death matter?. Psychology and Aging, 18, 193– 202Snowdon, D.A. , Kemper, S.J. , Mortimer, J.A. , Greiner, L.H. , Wekstein, D.R. , Markesbery, W.R. (1996). Linguistic ability in early life and cognitive function and Alzheimer's disease in late life. Findings from the Nun study. Journal of the American Medical Association, 275, 528– 532Whalley, L.J. , Deary, I.J. (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. British Medical Journal, 322, 819–Wilson, R.S. , Beckett, L.A. , Bienias, J.L. , Evans, D.A. , Bennett, D.A. (2003). Terminal decline in cognitive function. Neurology, 60, 1782– 1787