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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

Population sample flow chart.
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Figure 1: Population sample flow chart.

Mentions: These data come from the inception cohort of the Canadian Study of Health and Aging (CSHA) [16], a representative survey of people aged 65 and over. The chief goals of the CSHA were to identify the prevalence, incidence outcomes of and risks for dementia. In the first phase (CSHA-1) data collection took place between February 1991 and May 1992. In Figure 1, the sample population is presented as a flow chart. Initially, 10,267 people were interviewed – 9,008 in the community, and the remainder in long-term care institutions. The response rate in the community was 72 % and was 82% for those in long-term care. Participants in the clinical component were selected from a random sample of elderly Canadians, based on their score on the Modified Mini-Mental Status Examination (3 MS) [17]. Those who screened positive, and a sample who screened negative were invited to a clinical examination designed to detect cognitive impairment and diagnose its cause (n = 2914). Demographic and diagnostic details have appeared elsewhere [16,18-20]. Briefly, of the 2914 who came for a clinical examination 64.4% were women. Their mean age at baseline was 82.0 years; SD 7.43, range 65–106. Dementia, and its subtypes, were diagnosed and staged by standard protocols, [16,19,20] based on the examination and an informant interview, in 1132 people. Of the remainder, 861 were classified as having Cognitive Impairment No Dementia (CIND) [19] and 921 with no cognitive impairment. All 1338 surviving clinical participants received a follow-up examination approximately five years after the baseline assessment [20]. Date of death was recorded for 1465 of the 1521 subjects who did not survive. The median time to death was 33 months.


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

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

Population sample flow chart.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC88955&req=5

Figure 1: Population sample flow chart.
Mentions: These data come from the inception cohort of the Canadian Study of Health and Aging (CSHA) [16], a representative survey of people aged 65 and over. The chief goals of the CSHA were to identify the prevalence, incidence outcomes of and risks for dementia. In the first phase (CSHA-1) data collection took place between February 1991 and May 1992. In Figure 1, the sample population is presented as a flow chart. Initially, 10,267 people were interviewed – 9,008 in the community, and the remainder in long-term care institutions. The response rate in the community was 72 % and was 82% for those in long-term care. Participants in the clinical component were selected from a random sample of elderly Canadians, based on their score on the Modified Mini-Mental Status Examination (3 MS) [17]. Those who screened positive, and a sample who screened negative were invited to a clinical examination designed to detect cognitive impairment and diagnose its cause (n = 2914). Demographic and diagnostic details have appeared elsewhere [16,18-20]. Briefly, of the 2914 who came for a clinical examination 64.4% were women. Their mean age at baseline was 82.0 years; SD 7.43, range 65–106. Dementia, and its subtypes, were diagnosed and staged by standard protocols, [16,19,20] based on the examination and an informant interview, in 1132 people. Of the remainder, 861 were classified as having Cognitive Impairment No Dementia (CIND) [19] and 921 with no cognitive impairment. All 1338 surviving clinical participants received a follow-up examination approximately five years after the baseline assessment [20]. Date of death was recorded for 1465 of the 1521 subjects who did not survive. The median time to death was 33 months.

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