A Longitudinal Study on the Association of Interrelated Factors Among Frailty Dimensions, Cognitive Domains, Cognitive Frailty, and All-Cause Mortality

Article type: Research Article

Authors: Chen, Jen-Hau^a | Shih, Hua-San^b | Tu, Jennifer^c | Chiou, Jeng-Min^d | Chang, Shu-Hui^b | Hsu, Wei-Li^{e; f} | Lai, Liang-Chuan^g | Chen, Ta-Fu^h | Chen, Yen-Ching^{b; i; *}

Affiliations: [a] Department of Geriatrics and Gerontology, National Taiwan University Hospital, Taipei, Taiwan | [b] Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan | [c] Duke University School of Medicine, Durham, NC, USA | [d] Institute of Statistical Science, Academia Sinica, Nankang District, Taipei, Taiwan | [e] School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan | [f] Physical Therapy Center, National Taiwan University Hospital, Taipei, Taiwan | [g] Graduate Institute of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan | [h] Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan | [i] Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan

Correspondence: [*] Correspondence to: Yen-Ching Chen, ScD, Professor, Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, No. 17, Xu-Zhou Road, Taipei 10055, Taiwan. Tel.: +886 2 33668019; Fax: +886 2 23511955; E-mail: karenchen@ntu.edu.tw.

Abstract: Background:Cognitive frailty integrating impaired cognitive domains and frailty dimensions has not been explored. Objective:This study aimed to explore 1) associations among frailty dimensions and cognitive domains over time and 2) the extended definitions of cognitive frailty for predicting all-cause mortality. Methods:This four-year cohort study recruited 521 older adults at baseline (2011–2013). We utilized 1) generalized linear mixed models exploring associations of frailty dimensions (physical dimension: modified from Fried et al.; psychosocial dimension: integrating self-rated health, mood, and social relationship and support; global frailty: combining physical and psychosocial frailty) with cognition (global and domain-specific) over time and 2) time-dependent Cox proportional hazard models assessing associations between extended definitions of cognitive frailty (cognitive domains-frailty dimensions) and all-cause mortality. Results:At baseline, the prevalence was 3.0% for physical frailty and 37.6% for psychosocial frailty. Greater physical frailty was associated with poor global cognition (adjusted odds ratio = 1.43–3.29, β: –1.07), logical memory (β: –0.14 to –0.10), and executive function (β: –0.51 to –0.12). Greater psychosocial frailty was associated with poor global cognition (β: –0.44) and attention (β: –0.15 to –0.13). Three newly proposed definitions of cognitive frailty, “mild cognitive impairment (MCI)-psychosocial frailty,” “MCI-global frailty,” and “impaired verbal fluency-global frailty,” outperformed traditional cognitive frailty for predicting all-cause mortality (adjusted hazard ratio = 3.49, 6.83, 3.29 versus 4.87; AIC = 224.3, 221.8, 226.1 versus 228.1). Conclusion:Notably, extended definitions of cognitive frailty proposed by this study better predict all-cause mortality in older adults than the traditional definition of cognitive frailty, highlighting the importance of psychosocial frailty to reduce mortality in older adults.

Keywords: Cognition, cohort study, frailty, mortality

DOI: 10.3233/JAD-215111

Journal: Journal of Alzheimer's Disease, vol. 84, no. 4, pp. 1795-1809, 2021