Recalibration and validation of the Charlson comorbidity index in Korean incident hemodialysis patients

Development and validation of a social alienation predictive model for older maintenance hemodialysis patients based on latent profile analysis-a cross-sectional study

BACKGROUND

Social alienation refers to the state of feeling isolated, helpless, and unsatisfied due to maintaining distance from others or avoiding social interaction and activities. This phenomenon is caused by a lack of social skills, social anxiety, physical health problems, and other reasons. Older maintenance hemodialysis patients are exposed to a higher risk of social alienation. However, previous studies have been performed using the total score of the scale, which does not allow the identification of the characteristics of various patient groups with different levels of social alienation. In contrast, latent profile analysis can classify individuals into different categories based on continuous observational indicators, which improves accuracy and provides a more objective assessment by accounting for the uncertainty of variables. Given the concealed nature of social alienation and the differences in characteristics and treatment measures between different profiles, developing a predictive model for social alienation in older maintenance hemodialysis patients holds significance.

OBJECTIVE

To explore the latent profile analysis of social alienation in older maintenance hemodialysis patients and to develop and validate a predictive model for social alienation in this population.

METHODS

A total of 350 older maintenance hemodialysis patients were selected as the study subjects using convenience sampling. A cross-sectional survey was conducted using a general information questionnaire, the Generalized Alienation Scale, and the Self-Perceived Burden Scale. Based on the results of the Generalized Alienation Scale, a latent profile analysis was performed, followed by univariate analysis and multinomial logistic regression to develop a predictive model. The effectiveness of the predictive model was evaluated in terms of its authenticity, reliability, and predictive ability.

RESULTS

Three hundred nineteen valid questionnaires were collected. The social alienation of older maintenance hemodialysis patients based on latent profile analysis were divided into three profiles, which were named the low/medium/high-symptom groups, comprising 21%, 38.9%, and 40.1% of participants, respectively. Based on male, monthly social activity hours, Age-Adjusted Charlson Comorbidity Index, dialysis age, and Self-Perceived Burden Scale, a predictive model of social alienation for older maintenance hemodialysis patients was developed, and the Hosmer-Lemeshow tests showed no statistical significance (P > 0.05). The model has high predictive efficiency in authenticity, reliability and predictability.

CONCLUSION

Older maintenance hemodialysis patients exhibited moderate to high levels of social alienation. The latent profile analysis based method was used to divide patients into low/medium/high-symptom profiles, and the predictive model demonstrates excellent authenticity, reliability, and predictability.

Recalibration and validation of the Charlson Comorbidity Index in acute kidney injury patients underwent continuous renal replacement therapy

Background

Comorbid conditions impact the survival of patients with severe acute kidney injury (AKI) who require continuous renal replacement therapy (CRRT). The weights assigned to comorbidities in predicting survival vary based on type of index, disease, and advances in management of comorbidities. We developed a modified Charlson Comorbidity Index (CCI) for use in patients with AKI requiring CRRT (mCCI-CRRT) and improved the accuracy of risk stratification for mortality.

Methods

A total of 828 patients who received CRRT between 2008 and 2013, from three university hospital cohorts was included to develop the comorbidity score. The weights of the comorbidities were recalibrated using a Cox proportional hazards model adjusted for demographic and clinical information. The modified index was validated in a university hospital cohort (n = 919) using the data of patients treated from 2009 to 2015.

Results

Weights for dementia, peptic ulcer disease, any tumor, and metastatic solid tumor were used to recalibrate the mCCI-CRRT. Use of these calibrated weights achieved a 35.4% (95% confidence interval [CI], 22.1%–48.1%) higher performance than unadjusted CCI in reclassification based on continuous net reclassification improvement in logistic regression adjusted for age and sex. After additionally adjusting for hemoglobin and albumin, consistent results were found in risk reclassification, which improved by 35.9% (95% CI, 23.3%–48.5%).

Conclusion

The mCCI-CRRT stratifies risk of mortality in AKI patients who require CRRT more accurately than does the original CCI, suggesting that it could serve as a preferred index for use in clinical practice.

Smoothing transition to dialysis to improve early outcomes after dialysis initiation among old and frail adults-a narrative review

The number of patients ≥65 years of age suffering from advanced chronic kidney disease and transitioning to end-stage kidney disease (ESKD) is increasing. However, elderly patients often have poor outcomes once haemodialysis is initiated, including high mortality within the first year as well as fast cognitive and functional decline and diminished quality of life. The question is how we can smooth this transition to ESKD in older patients who also exhibit much higher proportions of frailty when compared with community-dwelling non-dialysis older adults and who are generally more vulnerable to invasive treatment such as kidney replacement therapy. To avoid early death and poor quality of life, a carefully prepared smooth transition should precede the initiation of treatment. This involves pre-dialysis physical and educational care, as well as mental and psychosocial preparedness of the patient to enable an informed and shared decision about the individual choice of treatment modality. Communication between a healthcare professional and patient plays a pivotal role but can be challenging given the high rate of cognitive impairment in this particular population. In order to practise patient-centred care, adapting treatment tailored to the individual patient should include comprehensive conservative care. However, structured treatment pathways including multidisciplinary teams for such conservative care are still rare and may be difficult to establish outside of large cities. Generally, geriatric nephrology misses data on the comparative effectiveness of different treatment modalities in this population of old and very old age on which to base recommendations and decisions.

Cross-sectional evaluation of the interaction between activity relative-time expenditure and comorbidity concerning physical quality of life

Quality of life (QoL) is a matter of concern in both healthy and diseased individuals. Lifestyle factors such as physical activity and sleep have a direct impact on QoL. In this context, interactions between activity time expenditure and QoL might be different in comorbid and non comorbid patients. Besides, the quantification and evaluation of time expenditure is ordinarily measured as the absolute time devoted to each activity. The objective of this study is the evaluation of the influence and interactions of activity-relative time expenditure and co-morbidity in Physical QoL.The study involved 302 consecutive patients, from an Internal Medicine ambulatory evaluation. Validated questionnaires were used to collect demographic variables and time expenditure variables. QoL was gathered with de survey short form-36questionnaire. Comorbidity was compiled with de Charlson Comorbidity Index. SPSS v20.0 was used for statistical analysis.As hypothesized, healthy subjects had higher Physical QoL score than comorbid subjects (P < .05). Physical activity and sleep relative time expenditure were statistically significant and associated to a better QoL in comorbid patients (P < .05). Interestingly, sleep was found to have statistically significant interaction with a score of ≥2 in the Charlson Comorbidity Index. Age, gender, comorbidity, physical activity relative time expenditure, and the interaction between relative time dedicated to sleep and comorbidity were found statistically significant in a multivariate model on Physical QoL prediction.Activity-relative time expenditure could be an adequate measure of daily activity pattern in the evaluation of QoL. Relative time spent in physical activity and sleep might be positively associated to Physical QoL. Sleep and comorbidity could have a statistically significant interaction in the prediction of Physical QoL.

Antioxidant Lifestyle, Co-Morbidities and Quality of Life Empowerment Concerning Liver Fibrosis

The assessment of liver fibrosis has gained importance since the progression of non-alcoholic fatty liver disease (NAFLD). Indeed, the description of the association between undetected liver fibrosis and lifestyle in terms of antioxidant habits, comorbidity and quality of life (QoL) domains may help in the characterization of subjects with NAFLD. A cross-sectional evaluation of (n = 116) consecutive patients from an Internal Medicine ambulatory evaluation was performed. Demographic data, lifestyle, co-morbidity, QoL (according to the SF-36 index) and analytical values to calculate the oxidative related Fibrosis-4 (FIB-4) index were recorded. The association between FIB-4 and co-morbidity, antioxidant habits in QoL was assessed in univariate analysis (p < 0.05) and confirmed in multivariable analysis for 4 of the 8 SF-36 categories: Physical QoL, Physical role, Social QoL and General QoL, as well as in the Physical summary of SF-36 (p < 0.05). Finally, interactions were assessed between co-morbidity, FIB-4 and antioxidant habits showed in the prediction of mean SF-36 (p < 0.01). Liver fibrosis assessed by the oxidative surrogate index FIB-4 is associated with the interaction between antioxidant lifestyle, co-morbidity and physical, social and general aspects of QoL in apparent liver disease-free individuals, generating a proof of concept for health empowerment and personalized medicine.

Recalibration and validation of the Charlson Comorbidity Index in an Asian population: the National Health Insurance Service-National Sample Cohort study

Weights assigned to comorbidities in predicting mortality may vary based on the type of index disease and advances in the management of comorbidities. We aimed to develop a modified version of the Charlson Comorbidity Index (CCI) using an Asian nationwide database (mCCI-A), enabling the precise prediction of mortality rates in this population. The main data source used in this study was the National Health Insurance Service-National Sample Cohort (NHIS-NSC) obtained from the National Health Insurance database, which includes health insurance claims filed between January 1, 2002, and December 31, 2013, in Korea. Of the 1,025,340 individuals included in the NHIS-NSC, 570,716 patients who were hospitalized at least once were analyzed in this study. In total, 399,502 patients, accounting for 70% of the cohort, were assigned to the development cohort, and the remaining patients (n = 171,214) were assigned to the validation cohort. The mCCI-A scores were calculated by summing the weights assigned to individual comorbidities according to their relative prognostic significance determined by a multivariate Cox proportional hazard model. The modified index was validated in the same cohort. The Cox proportional hazard model provided reassigned severity weights for 17 comorbidities that significantly predicted mortality. Both the CCI and mCCI-A were correlated with mortality. However, compared with the CCI, the mCCI-A showed modest but significant increases in the c statistics. According to the analyses using continuous net reclassification improvement, the mCCI-A improved the net mortality risk reclassification by 44.0% (95% confidence intervals (CI), 41.6–46.5; p < 0.001). The mCCI-A facilitates better risk stratification of mortality rates in Korean inpatients than the CCI, suggesting that the mCCI-A may be a preferable index for use in clinical practice and statistical analyses in epidemiological studies.

Effects of Repetitive Transcranial Magnetic Stimulation on Improvement of Mental Health and Clinical Parameters in Depressed Hemodialysis Patients: a Pilot Study

BACKGROUND

This study aimed to evaluate the therapeutic effect of repetitive transcranial magnetic stimulation (rTMS) as a nonpharmacologic treatment in depressed hemodialysis patients.

METHODS

Patients who scored ≥ 5 on the Patient Health Questionnaire-9 were randomized to either the rTMS (n = 7) or sham group (n = 7). The rTMS group was stimulated with a 110% motor threshold and 10 Hz on the left dorsolateral prefrontal cortex for 20 minutes, three times a week, for 4 weeks. In the sham group, the "1-wing 90-degree method" was used. We analyzed clinical indices before and after the intervention, as well as data from quantitative electroencephalography (frontal alpha asymmetry [FAA]), and various psychiatric questionnaires (Beck Depression Inventory-II, Beck Anxiety Inventory [BAI], Symptom Checklist-90-Revised Somatization Subscale [SCL-90R-SOM]), and Perceived Stress Scale.

RESULTS

One month after rTMS, the changes in hemoglobin A1c levels in the rTMS group were significantly greater than those in the sham group (F = 6.687, P = 0.032). The changes in BAI scores in the rTMS group were significantly greater than those in the sham group (F = 6.700, P = 0.025), and the changes in SCL-90R-SOM scores in the rTMS group were greater than those in the sham group (F = 4.943, P = 0.048). In addition, the changes in the FAA value at the F7 and F8 electrodes in the rTMS group were greater than those in the sham group (F = 6.468, P = 0.027).

CONCLUSION

In depressed hemodialysis patients, rTMS may improve anxiety and somatization symptoms, which may lead to improvements in clinical measures. Trial Registration Clinical Research Information Service Identifier: KCT0004082.

Associations between multimorbidity and adverse clinical outcomes in patients with chronic kidney disease: a systematic review and meta-analysis

OBJECTIVE

To systematically review the literature exploring the associations between multimorbidity (the presence of two or more long-term conditions (LTCs)) and adverse clinical outcomes in patients with chronic kidney disease (CKD).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Cochrane Library and SCOPUS (1946-2019). The main search terms were 'Chronic Kidney Failure' and 'Multimorbid*'.

ELIGIBILITY CRITERIA

Observational studies of adults over the age of 18 with CKD stages 3-5, that is, estimated glomerular filtration rate less than 60 mL/min/1.73 m2. The exposure was multimorbidity quantified by measures and the outcomes were all-cause mortality, renal progression, hospitalisation and cardiovascular events. We did not consider CKD as a comorbid LTC.

DATA EXTRACTION AND SYNTHESIS

Newcastle-Ottawa Scale for quality appraisal and risk of bias assessment and fixed effects meta-analysis for data synthesis.

RESULTS

Of 1852 papers identified, 26 met the inclusion criteria. 21 papers involved patients with advanced CKD and no studies were from low or middle-income countries. All-cause mortality was an outcome in all studies. Patients with multimorbidity were at higher risk of mortality compared with patients without multimorbidity (total risk ratio 2.28 (95% CI 1.81 to 2.88)). The risk of mortality was higher with increasing multimorbidity (total HR 1.31 (95% CI 1.27 to 1.36)) and both concordant and discordant LTCs were associated with heightened risk. Multimorbidity was associated with renal progression in four studies, hospitalisation in five studies and cardiovascular events in two studies.

LIMITATIONS

Meta-analysis could only include 10 of 26 papers as the methodologies of studies were heterogeneous.

CONCLUSIONS

There are associations between multimorbidity and adverse clinical outcomes in patients with CKD. However, most data relate to mortality risk in patients with advanced CKD. There is limited evidence regarding patients with mild to moderate CKD, outcomes such as cardiovascular events, types of LTCs and regarding patients from low or middle-income countries.

PROSPERO REGISTRATION NUMBER

CRD42019147424.

Prediction of the Mortality Risk in Peritoneal Dialysis Patients using Machine Learning Models: A Nation-wide Prospective Cohort in Korea

Herein, we aim to assess mortality risk prediction in peritoneal dialysis patients using machine-learning algorithms for proper prognosis prediction. A total of 1,730 peritoneal dialysis patients in the CRC for ESRD prospective cohort from 2008 to 2014 were enrolled in this study. Classification algorithms were used for prediction of N-year mortality including neural network. The survival hazard ratio was presented by machine-learning algorithms using survival statistics and was compared to conventional algorithms. A survival-tree algorithm presented the most accurate prediction model and outperformed a conventional method such as Cox regression (concordance index 0.769 vs 0.745). Among various survival decision-tree models, the modified Charlson Comorbidity index (mCCI) was selected as the best predictor of mortality. If peritoneal dialysis patients with high mCCI (>4) were aged ≥70.5 years old, the survival hazard ratio was predicted as 4.61 compared to the overall study population. Among the various algorithm using longitudinal data, the AUC value of logistic regression was augmented at 0.804. In addition, the deep neural network significantly improved performance to 0.841. We propose machine learning-based final model, mCCI and age were interrelated as notable risk factors for mortality in Korean peritoneal dialysis patients.

Developing an adapted Charlson comorbidity index for ischemic stroke outcome studies

Background

The Charlson comorbidity index (CCI) is commonly used to adjust for patient casemix. We reevaluated the CCI in an ischemic stroke (IS) cohort to determine whether the original seventeen comorbidities and their weights are relevant.

Methods

We identified an IS cohort (N = 6988) from the Ontario Stroke Registry (OSR) who were discharged from acute hospitals (N = 100) between April 1, 2012 and March 31, 2013. We used hospital discharge ICD-10-CA data to identify Charlson comorbidities. We developed a multivariable Cox model to predict one-year mortality retaining statistically significant (P < 0.05) comorbidities with hazard ratios ≥1.2. Hazard ratios were used to generate revised weights (1–6) for the comorbid conditions. The performance of the IS adapted Charlson comorbidity index (ISCCI) mortality model was compared to the original CCI using the c-statistic and continuous Net Reclassification Index (cNRI).

Results

Ten of the 17 Charlson comorbid conditions were retained in the ISCCI model and 7 had reassigned weights when compared to the original CCI model . The ISCCI model showed a small but significant increase in the c-statistic compared to the CCI for 30-day mortality (c-statistic 0.746 vs. 0.732, p = 0.009), but no significant increase in c-statistic for in-hospital or one-year mortality. There was also no improvement in the cNRI when the ISCCI model was compared to the CCI.

Conclusions

The ISCCI model had similar performance to the original CCI model. The key advantage of the ISCCI model is it includes seven fewer comorbidities and therefore easier to implement in situations where coded data is unavailable.

Life-threatening complications after pulmonary resection for lung cancer in patients on chronic hemodialysis

PURPOSE

The morbidity and mortality associated with lung cancer surgery in patients on chronic hemodialysis (CHD) is high; however, the relationship between the severity of postoperative complications and clinicopathological features is unclear.

METHODS

Among 1214 consecutive patients who underwent pulmonary resection for primary lung cancer in our institute between 2004 and 2015, we identified 21 patients on CHD, who were the subjects of this study. Life-threatening postoperative complications were defined as grade 4 and 5 per the Clavien-Dindo classification.

RESULTS

Fourteen (67%) of these 21 patients suffered postoperative complications, which were life threatening in 5. There was a higher frequency of interstitial pneumonia (IP) in the patients with life-threatening postoperative complications than in those with complications that were not life threatening (p = 0.032). The rates of acute exacerbation and 90-day mortality in the patients with IP were 50% and 75%, respectively. The overall survival (OS) rate of the patients with life-threatening postoperative complications was significantly lower than that of those with complications that were not life threatening (1- and 3-year OS rates: 40% and 0% vs. 80% and 57%, respectively, p = 0.001).

CONCLUSIONS

Postoperative mortality and morbidity were high in patients on CHD who underwent pulmonary resection, especially if they had coexisting IP. Although IP is not a contraindication to pulmonary resection, the surgical strategy for CHD patients with IP should be considered carefully.

The Number of Comorbidities Predicts Renal Outcomes in Patients with Stage 3⁻5 Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is a global health threat affecting approximately 10% of the adult population worldwide. Multimorbidity is common in CKD, but its impacts on disease outcomes are seldom investigated.

METHODS

This prospective cohort analysis followed patients, who were part of a multidisciplinary CKD care program, for 10 years. We aimed to determine the impact of multimorbidity on renal outcomes.

RESULTS

Overall, 1463 patients with stage 3⁻5 CKD were enrolled and stratified by the number of comorbidities. Mean follow-up time was 6.39 ± 1.19 years. We found that stage 3⁻5 CKD patients with at least three comorbidities at enrollment initiated dialysis earlier (hazard ratio (HR): 2.971) than patients without comorbidities. Risk factors for multimorbidity included old age, smoking, and proteinuria.

CONCLUSIONS

By analyzing the number of comorbidities, a simple and readily applicable method, we demonstrated an association between multimorbidity and poor renal outcomes in stage 3⁻5 CKD patients. In addition to current guideline-based approaches, our results suggest an urgent need for tailored CKD care strategies for high-risk groups.

Comorbidities Can Predict Mortality of Kidney Transplant Recipients: Comparison With the Charlson Comorbidity Index

BACKGROUND

Comorbid conditions are important in the survival of kidney transplant recipients. The weights assigned to comorbidities to predict survival may vary based on the type of index disease and advances in the management of comorbidities. We aimed to develop a modified Charlson comorbidity index (CCI) in renal allograft recipients (mCCI-KT), thereby improving risk stratification for mortality.

METHODS

A total of 3765 recipients in a multicenter cohort were included to develop a comorbidity score. The weights of the comorbidities, per the CCI, were recalibrated using a Cox proportional hazards model.

RESULTS

Peripheral vascular disease, liver disease, myocardial infarction, and diabetes in the CCI were selected from the Cox proportional hazards model. Thus, the mCCI-KT included 4 comorbidities with recalibrated severity weights. Whereas the CCI did not discriminate for survival, the mCCI-KT provided significant discrimination for survival using the Kaplan-Meier method and Cox regression analysis. The mCCI-KT showed modest increases in c-statistics (0.54 vs 0.52, P = .001) and improved net mortality risk reclassification by 16.3% (95% confidence interval, 3.2-29.4; P = .015) relative to the CCI.

CONCLUSION

The mCCI-KT stratifies the risk for mortality in renal allograft recipients better than the CCI, suggesting that it may be a preferred index for use in clinical practice.

Influence of Major Coping Strategies on Treatment Non-adherence and Severity of Comorbid Conditions in Hemodialysis Patients

BACKGROUND

Non-adherence and comorbidities are prevalent among hemodialysis patients and are associated with increased mortality and financial burden. We aimed to investigate the influence of major coping strategies (CSs) on non-adherence and comorbidities in hemodialysis patients.

METHODS

A total of 49 patients were enrolled. We collected participant data including CS measured by a Korean version of the ways of coping questionnaire (K-WCQ), comorbidities measured by age-adjusted Charlson comorbidity index (CCI), and adherence measured by the 8-item Morisky medication adherence scale (MMAS-8).

RESULTS

Regarding major CS, 61.2% of participants reported use of support-seeking CS (SUP group), 14.3% reported use of problem-focused CS (PRO group), and 24.5% reported use of hopeful-thinking CS (HOP group). The mean MMAS-8 score was higher in the PRO group than in the HOP group (P = 0.024). The mean CCI score was lower in the PRO group than in the HOP group (P = 0.017). In the HOP group, the severity of somatic symptoms was positively correlated with the scores for the emotion-focused CS subscale (r = 0.39, P = 0.029) and the hopeful-thinking CS subscale (r = 0.38, P = 0.036) of the K-WCQ. The level of life satisfaction positively correlated with the score for the problem-focused CS subscale in the HOP group (r = 0.40, P = 0.027).

CONCLUSION

We should pay more attention to the CSs of hemodialysis patients and provide interventions that promote problem-focused CSs, especially for nonadherent patients with high comorbidity rates who mainly use a hopeful-thinking CS.

Development and Validation of the Modified Charlson Comorbidity Index in Incident Peritoneal Dialysis Patients: A National Population-Based Approach

Background

The utility of applying the Charlson comorbidity index (CCI) to peritoneal dialysis (PD) patients is disputed because the relative weight of each comorbidity in PD patients may be different from those in other chronic diseases. We aimed to develop and validate a modified CCI in incident PD patients (mCCI-IPD) for better risk stratification and prediction of mortality.

Methods

The mCCI-IPD was developed using data from all Korean adult incident PD patients between 2005 and 2008 ( n = 7,606). Multivariate Cox regression was used to determine new weights for the individual comorbidities in the CCI. The prognostic performance of the mCCI-IPD was validated in an independent cohort ( n = 664) through c-statistics and continuous net reclassification improvement (cNRI).

Results

A total of 75.5% of the patients in the development cohort had 1 or more comorbidities. The Cox proportional hazards model provided reassigned severity weights for the 11 comorbidities that significantly predicted mortality. In the validation cohort, the CCI and mCCI-IPD scores were both correlated with survival and showed no differences in their c-statistics. However, multivariate analyses using cNRI revealed that the mCCI-IPD provided a 38.2% improvement in mortality risk assessment compared with the CCI (95% confidence interval [CI], 15.3 – 61.0; p < 0.001). These significant reclassification improvements were observed consistently in subjects with events (cNRIEvent, 28.2% [95% CI, 6.9 – 49.5; p = 0.009]) and without events (cNRINon-event, 10.0% [95% CI, 1.7 – 18.2; p = 0.019]).

Conclusions

Compared with the CCI, the mCCI-IPD showed better performance in mortality prediction for incident PD patients. Therefore, this tool may be used as a preferred index for statistical analysis and clinical decision-making.

Functional and Cognitive Impairment, Frailty, and Adverse Health Outcomes in Older Patients Reaching ESRD-A Systematic Review

BACKGROUND AND OBJECTIVES

Older patients reaching ESRD have a higher risk of adverse health outcomes. We aimed to determine the association of functional and cognitive impairment and frailty with adverse health outcomes in patients reaching ESRD. Understanding these associations could ultimately lead to prediction models to guide tailored treatment decisions or preventive interventions.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We searched MEDLINE, Embase, Web of Science, CENTRAL, CINAHL, PsycINFO, and COCHRANE for original studies published until February 8, 2016 reporting on the association of functional or cognitive impairment or frailty with adverse health outcome after follow-up in patients reaching ESRD either with or without RRT.

RESULTS

Of 7451 identified citations, we included 30 articles that reported on 35 associations. Mean age was >60 years old in 73% of the studies, and geriatric conditions were highly prevalent. Twenty-four studies (80%) reported on functional impairment, seven (23%) reported on cognitive impairment, and four (13%) reported on frailty. Mortality was the main outcome measure in 29 studies (97%), and one study assessed functional status trajectory. In 34 of 35 (97%) associations reported, functional or cognitive impairment or frailty was significantly and independently associated with adverse health outcomes. The majority of studies (83%) were conducted in selected patient populations, mainly patients on incident dialysis.

CONCLUSIONS

Functional and cognitive impairment and frailty in patients reaching ESRD are highly prevalent and strongly and independently associated with adverse health outcomes, and they may, therefore, be useful for risk stratification. More research into their prognostic value is needed.