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Abstract Background Frailty in individuals can be operationalized as the accumulation of health deficits, for which several trends have been observed in Western countries. Less is known about deficit accumulation in China, the country with the world's largest number of older adults. Methods This study analyzed data from the Beijing Longitudinal Study of Aging, to evaluate the relationship between age and deficit accumulation in men and women and to evaluate the impact of frailty on mortality. Community dwelling people aged 55+ years at baseline (n = 3275) were followed every two to three years between 1992 and 2000, during which time 36% died. A Frailty Index was constructed using 35 deficits, drawn from a range of health problems, including symptoms, disabilities, disease, and psychological difficulties. Results Most deficits increased the eight-year risk of death and were more lethal in men than in women, although women had a higher mean level of frailty (Frailty Index = 0.11 ± 0.10 for men, 0.14 ± 0.12 for women). The Frailty Index increased exponentially with age, with a similar rate in men and women (0.038 vs. 0.039; r > 0.949, P < 0.01). A dose-response relationship was observed as frailty increased. Conclusions A Frailty Index employed in a Chinese sample, showed properties comparable with Western data, but deficit accumulation appeared to be more lethal than in the West.

Abstract Background Frailty can be measured in relation to the accumulation of deficits using a frailty index. A frailty index can be developed from most ageing databases. Our objective is to systematically describe a standard procedure for constructing a frailty index. Methods This is a secondary analysis of the Yale Precipitating Events Project cohort study, based in New Haven CT. Non-disabled people aged 70 years or older (n = 754) were enrolled and re-contacted every 18 months. The database includes variables on function, cognition, co-morbidity, health attitudes and practices and physical performance measures. Data came from the baseline cohort and those available at the first 18-month follow-up assessment. Results Procedures for selecting health variables as candidate deficits were applied to yield 40 deficits. Recoding procedures were applied for categorical, ordinal and interval variables such that they could be mapped to the interval 0–1, where 0 = absence of a deficit, and 1= full expression of the deficit. These individual deficit scores were combined in an index, where 0= no deficit present, and 1= all 40 deficits present. The values of the index were well fit by a gamma distribution. Between the baseline and follow-up cohorts, the age-related slope of deficit accumulation increased from 0.020 (95% confidence interval, 0.014–0.026) to 0.026 (0.020–0.032). The 99% limit to deficit accumulation was 0.6 in the baseline cohort and 0.7 in the follow-up cohort. Multivariate Cox analysis showed the frailty index, age and sex to be significant predictors of mortality. Conclusion A systematic process for creating a frailty index, which relates deficit accumulation to the individual risk of death, showed reproducible properties in the Yale Precipitating Events Project cohort study. This method of quantifying frailty can aid our understanding of frailty-related health characteristics in older adults.

Abstract Background On average, health worsens with age, but many people have periods of improvement. A stochastic model provides an excellent description of how such changes occur. Given that cognition also changes with age, we wondered whether the same model might also describe the accumulation of errors in cognitive test scores in community-dwelling older adults. Methods In this prospective cohort study, 8954 older people (aged 65+ at baseline) from the Canadian Study of Health and Aging were followed for 10 years. Cognitive status was defined by the number of errors on the 100-point Modified Min-Mental State Examination. The error count was chosen to parallel the deficit count in the general model of aging, which is based on deficit accumulation. As with the deficit count, a Markov chain transition model was employed, with 4 parameters. Results On average, the chance of making errors increased linearly with the number of errors present at each time interval. Changes in cognitive states were described with high accuracy (R2 = 0.96) by a modified Poisson distribution, using four parameters: the background chance of accumulating additional errors, the chance of incurring more or fewer errors, given the existing number, and the corresponding background and incremental chances of dying. Conclusion The change in the number of errors in a cognitive test corresponded to a general model that also summarizes age-related changes in deficits. The model accounts for both improvement and deterioration and appears to represent a clinically relevant means of quantifying how various aspects of health status change with age.

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.

Abstract Objective Early frailty may be captured by a frailty index (FI) based entirely on vital signs and laboratory tests. Our aim was to examine associations between a laboratory‐based FI (FI‐Lab) and adverse health outcomes, and investigate how this changed with age. Methods Up to 8988 individuals aged 20+ years from the 2003‐2004 and 2005‐2006 National Health and Nutrition Examination Survey cohorts were included. Characteristics of the FI‐Lab were compared to those of a self‐reported clinical FI. Associations between each FI and health care use, self‐reported health, and disability were examined in the full sample and across age groups. Results Laboratory‐based FI scores increased with age but did not demonstrate expected sex differences. Women aged 20‐39 years had higher FI scores than men; this pattern reversed after age 60 years. FI‐Lab scores were associated with poor self‐reported health (odds ratio[95% confidence interval]: 1.46[1.39‐1.54]), high health care use (1.35[1.29‐1.42]), and high disability (1.41[1.32‐1.50]), even among those aged 20‐39 years. Conclusion Higher FI‐Lab scores were associated with poor health outcomes at all ages. Associations in the youngest group support the notion that deficit accumulation occurs across the lifespan. FI‐Lab scores could be utilized as an early screening tool to identify deficit accumulation at the cellular and molecular level before they become clinically visible.

Background: Although there is no strict definition of frailty, it is generally accepted as a state of high vulnerability for adverse health outcomes at older age. Associations between frailty and mortality, dependence, and hospitalization have been shown. We measured the frailty level of older people with intellectual disabilities (ID). Furthermore variation in gender, age, and level of ID were identified. Results were compared to a frailty study in the general European population. Methods: This research elaborates on a large cross-sectional study: Healthy Ageing with Intellectual Disability (HA-ID). Nine hundred-eighty-two men and women (greater than or equal to 50yr) with ID were included. Based on the collected data, we developed a frailty index with 51 health-related deficits, and calculated a frailty index score between 0 and 1 for each individual. Deficits included physical, social and psychological problems. Results: The mean frailty index score was 0.27 (standard deviation 0.13). Frailty was positively correlated with age (r = 0.297, p less than 0.001). More severe ID was associated with higher frailty scores (beta = 0.440, p less than 0.001). The upper limit of the FI was 0.69, which was consistent for all age categories. Conclusion: As people with ID are getting older, the question whether additional years are spent in good health becomes salient. Here, people with ID over age 50 had frailty scores similar to most elderly people over 75y. Future research is needed to confirm if frail elderly people with ID have an increased risk of adverse health outcomes. (Contains 4 figures and 3 tables.)