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. 2022 May 1;51(5):afac075.
doi: 10.1093/ageing/afac075.

Frailty indices based on self-report, blood-based biomarkers and examination-based data in the Canadian Longitudinal Study on Aging

Joanna M Blodgett  1 , Mario U Pérez-Zepeda  1   2   3 , Judith Godin  1 , D Scott Kehler  1   4 , Melissa K Andrew  1 , Susan Kirkland  1   5 , Kenneth Rockwood  1 , Olga Theou  1   4
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Frailty indices based on self-report, blood-based biomarkers and examination-based data in the Canadian Longitudinal Study on Aging

Joanna M Blodgett et al. Age Ageing. .

Abstract

Background: Frailty can be operationalised using the deficit accumulation approach, which considers health deficits across multiple domains. We aimed to develop, validate and compare three different frailty indices (FI) constructed from self-reported health measures (FI-Self Report), blood-based biomarkers (FI-Blood) and examination-based assessments (FI-Examination).

Methods: Up to 30,027 participants aged 45-85 years from the baseline (2011-2015) comprehensive cohort of the Canadian Longitudinal Study on Aging were included in the analyses. Following standard criteria, three FIs were created: a 48-item FI-Self Report, a 23-item FI-Blood and a 47-item FI-Examination. In addition a 118-item FI-Combined was constructed. Mortality status was ascertained in July 2019.

Results: FI-Blood and FI-Examination demonstrated broader distributions than FI-Self Report. FI-Self Report and FI-Blood scores were higher in females, whereas FI-Examination scores were higher in males. All FI scores increased nonlinearly with age and were highest at lower education levels. In sex and age-adjusted models, a 0.01 increase in FI score was associated with a 1.08 [95% confidence interval (CI): 1.07,1.10], 1.05 (1.04,1.06), 1.07 (1.05,1.08) and a 1.13 (1.11,1.16) increased odds of mortality for FI-Self Report, FI-Blood, FI-Examination and FI-Combined, respectively. Inclusion of the three distinct FI types in a single model yielded the best prognostic accuracy and model fit, even compared to the FI-Combined, with all FIs remaining independently associated with mortality.

Conclusion: Characteristics of all FIs were largely consistent with previously established FIs. To adequately capture frailty levels and to improve our understanding of the heterogeneity of ageing, FIs should consider multiple types of deficits including self-reported, blood and examination-based measures.

Keywords: Canadian Longitudinal Study on Aging (CLSA); Frailty; ageing; epidemiology; older people.

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Figures

Figure 1
Figure 1
Distribution of (A) FI-Self Report; (B) FI-Blood; (C) FI-Examination and (D) FI-Combined.
Figure 2
Figure 2
Age association by sex of the (A) FI-Self Report; (B) FI-Blood; (C) FI-Examination and (D) FI-Combined.
See this image and copyright information in PMC

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