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Frailty, fitness and late-life mortality in relation to chronological and biological age.

Mitnitski AB, Graham JE, Mogilner AJ, Rockwood K - BMC Geriatr (2002)

Bottom Line: From the frailty index, relative (to CA) fitness and frailty were estimated, as was an individual's biological age.The average value of the frailty index increased with age in a log-linear relationship (r = 0.91; p < 0.001).The frailty index is a sensitive predictor of survival.

View Article: PubMed Central - HTML - PubMed

Affiliation: Ecole Polytechnique, Montreal QB, Canada. arnold@grbb.polymtl.ca

ABSTRACT

Background: People age at remarkably different rates, but how to estimate trajectories of senescence is controversial.

Methods: In a secondary analysis of a representative cohort of Canadians aged 65 and over (n = 2914) we estimated a frailty index based on the proportion of 20 deficits observed in a structured clinical examination. The construct validity of the index was examined through its relationship to chronological age (CA). The criterion validity was examined in its ability to predict mortality, and in relation to other predictions about aging. From the frailty index, relative (to CA) fitness and frailty were estimated, as was an individual's biological age.

Results: The average value of the frailty index increased with age in a log-linear relationship (r = 0.91; p < 0.001). In a Cox regression analysis, biological age was significantly more highly associated with death than chronological age. The average increase in the frailty index (i.e. the average accumulation of deficits) amongst those with no cognitive impairment was 3 per cent per year.

Conclusions: The frailty index is a sensitive predictor of survival. As the index includes items not traditionally related to adverse health outcomes, the finding is compatible with a view of frailty as the failure to integrate the complex responses required to maintain function.

No MeSH data available.


Related in: MedlinePlus

Mean proportion of deficits at any given age for subjects with no cognitive impairment. Solid circles represent the proportion of the deficits averaged across all subjects at age CA: In (q) = - 4.23 + 0.03 CA. Correlation coefficient, r = 0.91, p < 0.0001
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Figure 4: Mean proportion of deficits at any given age for subjects with no cognitive impairment. Solid circles represent the proportion of the deficits averaged across all subjects at age CA: In (q) = - 4.23 + 0.03 CA. Correlation coefficient, r = 0.91, p < 0.0001

Mentions: Figure 4 presents the log of the mean value of the frailty index. Consistent with our hypothesis, the frailty index value increases with age. Because age and the frailty index are well correlated (r = 0.91, p < 0.001) we can use this information to estimate relative fitness and frailty, with reasonable precision, across the age spectrum. The regression line corresponds to the equation:


Frailty, fitness and late-life mortality in relation to chronological and biological age.

Mitnitski AB, Graham JE, Mogilner AJ, Rockwood K - BMC Geriatr (2002)

Mean proportion of deficits at any given age for subjects with no cognitive impairment. Solid circles represent the proportion of the deficits averaged across all subjects at age CA: In (q) = - 4.23 + 0.03 CA. Correlation coefficient, r = 0.91, p < 0.0001
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC88955&req=5

Figure 4: Mean proportion of deficits at any given age for subjects with no cognitive impairment. Solid circles represent the proportion of the deficits averaged across all subjects at age CA: In (q) = - 4.23 + 0.03 CA. Correlation coefficient, r = 0.91, p < 0.0001
Mentions: Figure 4 presents the log of the mean value of the frailty index. Consistent with our hypothesis, the frailty index value increases with age. Because age and the frailty index are well correlated (r = 0.91, p < 0.001) we can use this information to estimate relative fitness and frailty, with reasonable precision, across the age spectrum. The regression line corresponds to the equation:

Bottom Line: From the frailty index, relative (to CA) fitness and frailty were estimated, as was an individual's biological age.The average value of the frailty index increased with age in a log-linear relationship (r = 0.91; p < 0.001).The frailty index is a sensitive predictor of survival.

View Article: PubMed Central - HTML - PubMed

Affiliation: Ecole Polytechnique, Montreal QB, Canada. arnold@grbb.polymtl.ca

ABSTRACT

Background: People age at remarkably different rates, but how to estimate trajectories of senescence is controversial.

Methods: In a secondary analysis of a representative cohort of Canadians aged 65 and over (n = 2914) we estimated a frailty index based on the proportion of 20 deficits observed in a structured clinical examination. The construct validity of the index was examined through its relationship to chronological age (CA). The criterion validity was examined in its ability to predict mortality, and in relation to other predictions about aging. From the frailty index, relative (to CA) fitness and frailty were estimated, as was an individual's biological age.

Results: The average value of the frailty index increased with age in a log-linear relationship (r = 0.91; p < 0.001). In a Cox regression analysis, biological age was significantly more highly associated with death than chronological age. The average increase in the frailty index (i.e. the average accumulation of deficits) amongst those with no cognitive impairment was 3 per cent per year.

Conclusions: The frailty index is a sensitive predictor of survival. As the index includes items not traditionally related to adverse health outcomes, the finding is compatible with a view of frailty as the failure to integrate the complex responses required to maintain function.

No MeSH data available.


Related in: MedlinePlus