Evelyne A. Gahbauer

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.

BACKGROUND: Little is known about the natural course of frailty. We performed a prospective study to determine the transition rates between frailty states and to evaluate the effect of the preceding frailty state on subsequent frailty transitions. METHODS: We studied 754 community-living persons, aged 70 years or older, who were nondisabled in 4 essential activities of daily living. Frailty, assessed every 18 months for 54 months, was defined on the basis of weight loss, exhaustion, low physical activity, muscle weakness, and slow walking speed. Participants were classified as frail if they met 3 or more of these criteria, as prefrail if they met 1 or 2 of the criteria, and as nonfrail if they met none of the criteria. RESULTS: Of the 754 participants, 434 (57.6%) had at least 1 transition between any 2 of the 3 frailty states during 54 months. The rates were 36.8%, 21.5%, and 9.2% for 1, 2, and 3 transitions, respectively. During the 18-month intervals, transitions to states of greater frailty were more common (rates up to 43.3%) than transitions to states of lesser frailty (rates up to 23.0%), and the probability of transitioning from being frail to nonfrail was very low (rates, 0%-0.9%), even during an extended period. The likelihood of transitioning between frailty states was highly dependent on one's preceding frailty state. CONCLUSIONS: Frailty among older persons is a dynamic process, characterized by frequent transitions between frailty states over time. Our findings suggest ample opportunity for the prevention and remediation of frailty.

BACKGROUND: Despite the importance of functional status to older persons and their families, little is known about the course of disability at the end of life. METHODS: We evaluated data on 383 decedents from a longitudinal study involving 754 community-dwelling older persons. None of the subjects had disability in essential activities of daily living at the beginning of the study, and the level of disability was ascertained during monthly interviews for more than 10 years. Information on the conditions leading to death was obtained from death certificates and comprehensive assessments that were completed at 18-month intervals after the baseline assessment. RESULTS: In the last year of life, five distinct trajectories were identified, from no disability to the most severe disability: 65 subjects had no disability (17.0%), 76 had catastrophic disability (19.8%), 67 had accelerated disability (17.5%), 91 had progressive disability (23.8%), and 84 had persistently severe disability (21.9%). The most common condition leading to death was frailty (in 107 subjects [27.9%]), followed by organ failure (in 82 subjects [21.4%]), cancer (in 74 subjects [19.3%]), other causes (in 57 subjects [14.9%]), advanced dementia (in 53 subjects [13.8%]), and sudden death (in 10 subjects [2.6%]). When the distribution of the disability trajectories was evaluated according to the conditions leading to death, a predominant trajectory was observed only for subjects who died from advanced dementia (67.9% of these subjects had a trajectory of persistently severe disability) and sudden death (50.0% of these subjects had no disability). For the four other conditions leading to death, no more than 34% of the subjects had any of the disability trajectories. The distribution of disability trajectories was particularly heterogeneous among the subjects with organ failure (from 12.2 to 32.9% of the subjects followed a specific trajectory) and frailty (from 14.0 to 27.1% of the subjects followed a specific trajectory). CONCLUSIONS: In most of the decedents, the course of disability in the last year of life did not follow a predictable pattern based on the condition leading to death.

CONTEXT: Disability among older persons is a complex and highly dynamic process, with high rates of recovery and frequent transitions between states of disability. The role of intervening illnesses and injuries (ie, events) on these transitions is uncertain. OBJECTIVES: To evaluate the relationship between intervening events and transitions among states of no disability, mild disability, severe disability, and death and to determine the association of physical frailty with these transitions. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study conducted in greater New Haven, Connecticut, from March 1998 to December 2008 of 754 community-living persons aged 70 years or older who were nondisabled at baseline in 4 essential activities of daily living: bathing, dressing, walking, and transferring. Telephone interviews were completed monthly for more than 10 years to assess disability and ascertain exposure to intervening events, which included illnesses and injuries leading to either hospitalization or restricted activity. Physical frailty (defined as gait speed >10 seconds on the rapid gait test) was assessed every 18 months through 108 months. MAIN OUTCOME MEASURE: Transitions between no disability, mild disability, and severe disability and 3 transitions from each of these states to death, evaluated each month. RESULTS: Hospitalization was strongly associated with 8 of the 9 possible transitions, with increased multivariable hazard ratios (HRs) as high as 168 (95% confidence interval [CI], 118-239) for the transition from no disability to severe disability and decreased HRs as low as 0.41 (95% CI, 0.30-0.54) for the transition from mild disability to no disability. Restricted activity also increased the likelihood of transitioning from no disability to both mild and severe disability (HR, 2.59; 95% CI, 2.23-3.02; and HR, 8.03; 95% CI, 5.28-12.21), respectively, and from mild disability to severe disability (HR, 1.45; 95% CI, 1.14-1.84), but was not associated with recovery from mild or severe disability. For all 9 transitions, the presence of physical frailty accentuated the associations of the intervening events. For example, the absolute risk of transitioning from no disability to mild disability within 1 month after hospitalization for frail individuals was 34.9% (95% CI, 34.5%-35.3%) vs 4.9% (95% CI, 4.7%-5.1%) for nonfrail individuals. Among the possible reasons for hospitalization, fall-related injury conferred the highest likelihood of developing new or worsening disability. CONCLUSIONS: Among older persons, particularly those who were physically frail, intervening illnesses and injuries greatly increased the likelihood of developing new or worsening disability. Only the most potent events, ie, those leading to hospitalization, reduced the likelihood of recovery from disability.

IMPORTANCE: Little is known about functional trajectories of older persons in the year before and after admission to the intensive care unit (ICU) or how pre-ICU functional trajectories affect post-ICU functional trajectories and death. OBJECTIVES: To characterize functional trajectories in the year before and after ICU admission and to evaluate the associations among pre-ICU functional trajectories and post-ICU functional trajectories, short-term mortality, and long-term mortality. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of 754 community-dwelling persons 70 years or older, conducted between March 23, 1998, and December 31, 2012, in greater New Haven, Connecticut. The analytic sample included 291 participants who had at least 1 admission to an ICU through December 2011. MAIN OUTCOMES AND MEASURES: Functional trajectories in the year before and after an ICU admission based on 13 basic, instrumental, and mobility activities. Additional outcomes included short-term (30 day) and long-term (1 year) mortality. RESULTS: The mean (SD) age of participants was 83.7 (5.5) years. Three distinct pre-ICU functional trajectories identified were minimal disability (29.6%), mild to moderate disability (44.0%), and severe disability (26.5%). Seventy participants (24.1%) experienced early death, defined as death in the hospital (50 participants [17.2%]) or death after hospital discharge but within 30 days of admission (20 participants [6.9%]). Among the remaining 221 participants, 3 distinct post-ICU functional trajectories identified were minimal disability (20.8%), mild to moderate disability (28.1%), and severe disability (51.1%). More than half of the participants (53.4%) experienced functional decline or early death after critical illness. The pre-ICU functional trajectories of mild to moderate disability and severe disability were associated with more than double (adjusted hazard ratio [HR], 2.41; 95% CI, 1.29-4.50) and triple (adjusted HR, 3.84; 95% CI, 1.84-8.03) the risk of death within 1 year of ICU admission, respectively. Other factors associated with 1-year mortality included ICU length of stay (adjusted HR, 1.03; 95% CI, 1.00-1.05), mechanical ventilation (adjusted HR, 2.89; 95% CI, 1.91-4.37), and shock (adjusted HR, 2.68; 95% CI, 1.63-4.38). CONCLUSIONS AND RELEVANCE: Among older persons with critical illness, more than half died within 1 month or experienced significant functional decline over the following year, with particularly poor outcomes in those who had high levels of premorbid disability. These results may help to inform discussions about prognosis and goals of care before and during critical illness.