Use of the Frailty Index in Older Persons With Chronic Kidney Disease

Intrinsic capacity and frailty in older adults with end-stage kidney disease undergoing pre-kidney transplant comprehensive geriatric assessment

OBJECTIVE

Frailty has been extensively studied in end-stage kidney disease (ESKD) and kidney transplant (KT) patients. The identification of frailty is useful to predict adverse outcomes among ESKD and KT patients. The recent concept of intrinsic capacity (IC) appears as a good and easy-to-understand tool to screen for and monitor frailty in older adults with ESKD. This study aims to assess the relationships between frailty and IC in older adults with ESKD awaiting KT.

DESIGN

Cross-sectional study SETTING AND PARTICIPANTS: 236 patients from a day-care geriatric unit undergoing pre-KT geriatric assessment between 2017 and 2022 were included in the main sample, and 151 patients in an independent multicentric replication sample.

MEASUREMENTS

Frailty was evaluated using the physical frailty phenotype (PFP) and IC measures using the World Health Organization's screening (step 1) and diagnostic (step 2) tools for five IC domains (vitality, locomotion, audition, cognition, psychology). Multivariate regressions were run to assess relationships between PFP and IC domains, adjusted for age, sex, and comorbidities. Analyses were replicated using another independent multicenter cohort including 151 patients with ESKD to confirm the results.

RESULTS

Impairments in the locomotion, psychology, and vitality IC domains according to WHO screening tools were associated with frailty (odds ratio 9.62 [95% CI 4.09-24.99], 3.19 [95% CI 1.11-8.88], and 3.11 [95% CI 1.32-7.29], respectively). When IC were measured linearly with z-scores, all IC domains except hearing were inversely associated with frailty. In the replication cohort, results were overall similar, with a greater association between psychology domain and frailty.

CONCLUSION

This study highlights the relationship between frailty and IC in ESKD patients. We assume that IC may be assessed and monitored in ESKD patients, to predict and prevent future frailty, and post-KT adverse outcomes.

Narrative Review: Clinical Implications and Assessment of Frailty in Patients With Advanced CKD

Frailty is a multidimensional clinical syndrome characterized by low physical activity, reduced strength, accumulation of multiorgan deficits, decreased physiological reserve, and vulnerability to stressors. Frailty has key social, psychological, and cognitive implications. Frailty is accelerated by uremia, leading to a high prevalence of frailty in patients with advanced chronic kidney disease (CKD) and end-stage kidney disease (ESKD) as well as contributing to adverse outcomes in this patient population. Frailty assessment is not routine in patients with CKD; however, a number of validated clinical assessment tools can assist in prognostication. Frailty assessment in nephrology populations supports shared decision-making and advanced communication and should inform key medical transitions. Frailty screening and interventions in CKD or ESKD are a developing research priority with a rapidly expanding literature base.

Use of frailty assessment instruments in nephrology populations: a scoping review

BACKGROUND

Frailty is a clinical syndrome of accelerated aging associated with adverse outcomes. Frailty is prevalent among patients with chronic kidney disease but is infrequently assessed in clinical settings, due to lack of consensus regarding frailty definitions and diagnostic tools. This study aimed to review the practice of frailty assessment in nephrology populations and evaluate the context and timing of frailty assessment.

METHODS

The search included published reports of frailty assessment in patients with chronic kidney disease, undergoing dialysis or in receipt of a kidney transplant, published between January 2000 and November 2021. Medline, CINAHL, Embase, PsychINFO, PubMed and Cochrane Library databases were examined. A total of 164 articles were included for review.

RESULTS

We found that studies were most frequently set within developed nations. Overall, 161 studies were frailty assessments conducted as part of an observational study design, and 3 within an interventional study. Studies favoured assessment of participants with chronic kidney disease (CKD) and transplant candidates. A total of 40 different frailty metrics were used. The most frequently utilised tool was the Fried frailty phenotype. Frailty prevalence varied across populations and research settings from 2.8% among participants with CKD to 82% among patients undergoing haemodialysis. Studies of frailty in conservatively managed populations were infrequent (N = 4). We verified that frailty predicts higher rates of adverse patient outcomes. There is sufficient literature to justify future meta-analyses.

CONCLUSIONS

There is increasing recognition of frailty in nephrology populations and the value of assessment in informing prognostication and decision-making during transitions in care. The Fried frailty phenotype is the most frequently utilised assessment, reflecting the feasibility of incorporating objective measures of frailty and vulnerability into nephrology clinical assessment. Further research examining frailty in low and middle income countries as well as first nations people is required. Future work should focus on interventional strategies exploring frailty rehabilitation.

Development of an Administrative Data-Based Frailty Index for Older Adults Receiving Dialysis

Background

Frailty is present in ≥50% of older adults receiving dialysis. Our objective was to a develop an administrative data–based frailty index and assess the frailty index’s predictive validity for mortality and future hospitalizations.

Methods

We used United States Renal Data System data to establish two cohorts of adults aged ≥65 years, initiating dialysis in 2013 and in 2017. Using the 2013 cohort (development dataset), we applied the deficit accumulation index approach to develop a frailty index. Adjusting for age and sex, we assessed the extent to which the frailty index predicts the hazard of time until death and time until first hospitalization over 12 months. We assessed the Harrell’s C-statistic of the frailty index, a comorbidity index, and jointly. The 2017 cohort was used as a validation dataset.

Results

Using the 2013 cohort (n=20,974), we identified 53 deficits for the frailty index across seven domains: disabilities, diseases, equipment, procedures, signs, tests, and unclassified. Among those with ≥1 deficit, the mean (SD) frailty index was 0.30 (0.13), range 0.02–0.72. Over 12 months, 18% (n=3842) died, and 55% (n=11,493) experienced a hospitalization. Adjusted hazard ratios for each 0.1-point increase in frailty index in models of time to death and time to first hospitalization were 1.41 (95% confidence interval, 1.37 to 1.44) and 1.33 (95% confidence interval, 1.31 to 1.35), respectively. For mortality, C-statistics for frailty index, comorbidity index, and both indices were 0.65, 0.65, and 0.66, respectively. For hospitalization, C-statistics for frailty index, comorbidity index, and both indices were 0.61, 0.60, and 0.61, respectively. Data from the 2017 cohort were similar.

Conclusions

We developed a novel frailty index for older adults receiving dialysis. Further studies are needed to improve on this frailty index and validate its use for clinical and research applications.

Frailty phenotype and multi-domain impairments in older patients with chronic kidney disease

BACKGROUND

Older subjects with chronic kidney disease (CKD) are often affected by multiple geriatric impairments that may benefit from a comprehensive geriatric assessment (CGA). However, ordinary execution of CGA in all these individuals would be unaffordable. We evaluated if Frailty Phenotype (FP) could identify older CKD-patients that may benefit the most from a CGA.

METHODS

We evaluated 112 CKD patients not yet on dialysis (age ≥ 65 years, eGFR < 45 ml/min). FP was defined according to the criteria proposed by Fried and co-authors. CGA evaluated four domains (nutrition, physical performance, cognition and depression). Malnutrition was defined in accordance to Malnutrition-Inflammation Score (MIS) and/or by the presence of Protein Energy Wasting syndrome (PEW). Physical performance was evaluated using Short Physical Performance Battery (SPPB) and handgrip strength. Cognitive status was assessed by using Mini Mental State Examination (MMSE) and Clock Drawing Test. Mood was investigated with Geriatric Depression Scale (GDS).

RESULTS

Average age of our cohort was 80 ± 6 years and mean eGFR 24 ± 11 ml/min/1.73 m2. Prevalence of frailty was 45%. Frail patients (F-CKD) had higher prevalence of malnutrition (58 vs 29%, p = 0.0005), physical impairment (100% vs 78%; p < 0.0001), cognitive dysfunction (83% vs 37%; p < 0.0001) and depression (50% vs 21%; p < 0.001) compared to robust ones (NF-CKD). Moreover, F-CKD patients had higher probability to have > 2 impaired domains (83% sensitivity and 76% specificity) respect to NF-CKD individuals.

CONCLUSIONS

FP is a reliable screening tool to identify older CKD-patients that may benefit from a CGA.

Using a genetic algorithm to derive a highly predictive and context-specific frailty index

The frailty index (FI) is one of the most widespread tools used to predict poor, health-related outcomes in older persons. The selection of clinical and functional deficits to include in a FI is mostly based on the users’ clinical experience. However, this approach may not be sufficiently accurate to predict health outcomes in particular subgroups of individuals. In this study, we implemented an optimization algorithm, the genetic algorithm, to create a highly performant (FI) based on our prediction goals, rather than on a predetermined clinical selection of deficits, using data from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K) and 109 potential deficits identified in the dataset. The algorithm was personalized to obtain a FI with high discrimination ability in the prediction of mortality. The resulting FI included 40 deficits and showed areas under the curve consistently higher than 0.80 (range 0.81-0.90) in the prediction of 3-year and 6-year mortality in the whole sample and in sex and age subgroups. This methodology represents a promising opportunity to optimize the exploitation of medical and administrative databases in the construction of clinically relevant frailty indices.

Survival advantage of initiating dialysis in elderly and non-elderly incident end-stage kidney disease patients

AIM

Many patients, especially the elderly, who require renal replacement therapies (RRT) have delayed or rejected dialysis for various reasons. Current dialysis guidelines may not be relevant for the elderly or frail patients. We aim to determine survival advantage of initiating dialysis in patients deemed to require RRT.

METHODS

This was an observational cohort on incident end-stage kidney disease (ESKD) patients from January 1, 2007 to December 31, 2008. The primary outcome was all-cause mortality. Patients contributed person-time from the date of ESKD diagnosis until death, transplant or end of study on December 31, 2014, whichever occurred first. An extended Cox regression model with time-varying exposure to dialysis was used to account for immortal time bias.

RESULTS

Of 3990 incident ESKD patients included, 70.2% patients initiated dialysis; 78.8% with haemodialysis (HD) while the remaining 21.2% with peritoneal dialysis (PD). Dialysis reduced hazard of death in both elderly and non-elderly patients even after controlling for comorbidities (hazard ratio [HR] 0.58, 95% confidence interval [CI] 0.50, 0.68 and HR 0.76, 95% CI 0.69, 0.85, respectively). HD was protective in both the elderly and non-elderly (HR 0.53, 95% CI 0.45, 0.63 and HR 0.71, 95% CI 0.64, 0.80, respectively). PD significantly reduced risk of death compared to no dialysis in the elderly but not in the non-elderly.

CONCLUSION

Dialysis improved survival in all incident ESKD patients. The findings suggested a larger protection offered by HD. Although improvement in survival from initiating dialysis was large, its true benefit should take overall quality of life into account. SUMMARY AT A GLANCE This observational study showed that initiation of dialysis improves the survival of end-stage kidney disease (ESKD) patients of all age groups, but the quality of life is an important aspect that has not been explored.

Frailty Screening in Chronic Kidney Disease: Current Perspectives

Frailty has been defined as a state of increased vulnerability as a consequence of deficit accumulation. Frailty screening has not yet been widely implemented into routine nephrology care. Patients with chronic kidney disease (CKD) are at high risk of being frail, and frailty has been associated with worse outcomes in this population. Standard management of CKD, including initiation of renal replacement therapies, may have decreased benefit or potentially cause harm in the presence of frailty, and a variety of interventions for modifying frailty in the CKD population have been proposed. The optimal means of screening for frailty in patients with kidney disease remains unclear. This review highlights the value of frailty screening in CKD by summarizing the outcomes associated with frailty and exploring proposed changes to the management of frail patients with CKD. Finally, we will propose a framework for how to implement frailty screening into standard nephrology care.