Disability and mortality trajectories of the oldest old in China
【Abstract】Using data collected from seven national follow-up surveys between 1998 and 2014 and a group-based trajectory model, this paper investigated ADL disability trajectories and mortality probability trajectories among the oldest old at the same time. We attempted to explain the membership in disability trajectory groups from three aspects, namely, demographic, socioeconomic and childhood characteristics. The analysis results showed that disability trajectories among the oldest old were heterogeneous. There were three trajectory groups for men, namely, one starting with a low level of disability that gradually progressed, one starting with a low level of disability that quickly progressed, and one starting with a high level of disability that gradually progressed. And there were three trajectory groups for women, too, namely, one starting with a low level of disability that gradually progressed, one starting with a low level of disability that quickly progressed, and one starting with a high level of disability that quickly progressed. Different groups of disability trajectories and mortality trajectories followed the same hierarchical distribution. Women’s mortality rate was often lower than men’s when they belonged to the same disability trajectory group. The residence location and the occupation affected the oldest old’ membership in disability trajectory groups.
【Keywords】 disability trajectory; mortality trajectory; group-based trajectory model; activity of daily living (ADLs); the oldest old;
1. Zeng, Y., Lu, J. & Lei, X. 中国健康老龄发展趋势和影响因素研究. Beijing: Science Press, (2018).
2 Zeng, Y. & Shen, K. Chinese Journal of Preventive Medicine (中华预防医学杂志), (2): 108−114, (2010).
3 Jiao, K. Medicine and Philosophy (Humanitarian and Social Medicine Edition) (医学与哲学 (人文社会医学版), (7): 33−35 (2009).
4 Wei, M. & Wang, H. Population and Development (人口与发展), (5): 74−81 (2017).
5 Wu, X. Population Research (人口研究), (4): 54−67 (2009).
6 Wu, X. & Liu, J. Population Journal (人口学刊), (4): 59−71 (2018).
7 The Research Group of China Research Center on Aging, Disability Research (残疾人研究), (2): 11−16 (2011).
8 Zhong, Y., Gao, Y. & Wang, J. Medicine and Philosophy (医学与哲学), (2): 37−39 (2014).
9 Andersen-Ranberg, K., Christensen, K., Jeune, B., Skytthe, A., Vasegaard, L. and Vaupel, J. W. 1999. Declining Physical Abilities with Age: A Cross-Sectional Study of Older Twins and Centenarians in Denmark. Age and Ageing 28: 373–377.
10 Haviland, A. M., Jones, B. L. and Nagin, D. S. 2011. Group-Based Trajectory Modeling Extended to Account for Nonrandom Participant Attrition. Sociological Methods & Research 40: 367–390.
11 Hirsch, C. H., Buzkova, P., Robbins, J. A., Patel, K. V. and Newman, A. B. 2012. Predicting Late-Life Disability and Death by the Rate of Decline in Physical Performance Measures (Dagger). Age and Ageing 41: 155–161.
12 Katz, S., Ford, A. B., Moskowitz, R. W., Jackson, B. A. and Jaffe, M. W. 1963. The Index of ADL: A Standardized Measure of Biological and Psychosocial Function. JAMA 185: 914–919.
13 Kingston, A., Davies, K., Collerton, J., Robinson, L., Duncan, R., Kirkwood, T. B. L. and Jagger, C. 2015. The Enduring Effect of Education-Socioeconomic Differences in Disability Trajectories From Age 85 Years in the Newcastle 85+Study. Archives of Gerontology and Geriatrics 60: 405–411.
14 Liang, J., McCarthy, J. F., Jain, A., Krause, N., Bennett, J. M. and Gu, S. 2000. Socioeconomic Gradient in Old Age Mortality in Wuhan, China. The Journals of Gerontology Series B: Psychological Sciences and Social Sciences 55: S222–S233.
15 Martin, L. G., Zimmer, Z. and Lee, J. 2017. Foundations of Activity of Daily Living Trajectories of Older Americans. Journals of Gerontology Series B-Psychological Sciences and Social Sciences 72: 129–139.
16 Nagin, D. 2005. Group-Based Modeling of Development. Cambridge, Mass: Harvard University Press.
17 United Nations DESA / Population Division. 2017. World Population Prospects: The 2017 Revision. New York: United Nations.
18 Wang, X. and Chen, P. 2014. Population Ageing Challenges Health Care in China. Lancet 383: 870.
19 Zeng, Y., Gu, D. and Land, K. C. 2007. The Association of Childhood Socioeconomic Conditions with Healthy Longevity at the oldest old Ages in China. Demography 44: 497–518.
20 Zeng, Y. and Vaupel, J. W. 2002. Functional Capacity and Self-Evaluation of Health and Life of Oldest Old in China. Journal of Social Issues 58: 733–748.
21 Zimmer, Z., Martin, L. G., Nagin, D. S. and Jones, B. L. 2012. Modeling Disability Trajectories and Mortality of the oldest old in China. Demography 49: 291–314.