Explaining trends and variation in timing of dialysis initiation in the United States

Dialysis for older adults: why should the targets be different?

The number of patients aged > 75-years treated by dialysis continues to increase, particularly in developed countries. Haemodialysis is a well-established treatment with national and international clinical guidelines designed to provide patients with optimal treatment. However, these were developed when the dialysis population was younger, and less co-morbid. This change in patient demographics questions whether these guideline targets still apply to older patients. More patients now start dialysis with residual kidney function and could benefit from a less frequent dialysis schedule. Older patients have a lower thirst drive, so lower interdialytic gains, reduced appetite, muscle mass and physical activity would potentially allow starting dialysis with less frequent sessions a practical option. Similarly, patients with residual kidney function and lower metabolic activity may not need to meet current dialyser Kt/Vurea clearance targets to remain healthy. Instead, some elderly patients may be at risk of malnutrition and might need liberalisation of the low salt, potassium and phosphate dietary restrictions, or even additional supplements to ensure adequate protein intake. Although a fistula is the preferred vascular access, a forearm fistula may not be an option due to vascular disease, while a brachial fistula can potentially compromise cardiovascular reserve, so a dialysis catheter becomes the de facto access, especially in patients with limited life expectancy. Thus, clinical guideline targets designed for a younger less co-morbid dialysis population may not be equally applicable to the older patient initiating dialysis, and so a more individualised approach to dialysis prescription and vascular access is required.

Geographic Dialysis Facility Density and Early Dialysis Initiation

Importance

The decision of when to start maintenance hemodialysis may be affected by health system-level support for high-intensity care as manifested by area dialysis facility density. Yet an association between early hemodialysis initiation and higher area density of dialysis facilities has not been shown.

Objective

To examine whether there is an association between area dialysis facility density and earlier dialysis initiation.

Design, Setting, and Participants

Cross-sectional analysis was conducted of publicly reported claims and geographic-based population data collected in the Medical Evidence files of the US Renal Data System (USRDS), a comprehensive registry of all patients initiating hemodialysis in the US, from calendar years 2011 through 2019. Data were linked to the American Community Survey, using residential zip codes, and then to health service area (HSA) primary care and hospitalization benchmarks, using the Dartmouth Atlas crosswalk. Data were analyzed from November 1, 2021, to August 31, 2023.

Exposure

Dialysis facility density at the level of HSA (number of dialysis facilities per 100 000 HSA residents) split into 5 categories.

Main Outcomes and Measures

The odds of hemodialysis initiation at an estimated glomerular filtration rate (eGFR) greater than 10 mL/min/1.73 m2 vs less than or equal to 10 mL/min/1.73 m2.

Results

Hemodialysis was initiated in a total of 844 466 individuals at 3397 HSAs at a mean (SD) eGFR of 8.9 (3.8) mL/min/1.73 m2. Their mean (SD) age was 63.5 (14.7) years, and 484 346 participants (57.4%) were men. In the HSA category with the highest facility density, individuals were younger (63.3 vs 65.2 years in least-dense HSAs), poorer (mean percent of households living in poverty, 10.4% vs 8.4%), and more commonly had a higher percentage of Black individuals (40.6% vs 11.3%). More individuals in the dialysis-dense HSAs than least-dense HSAs had diabetes (60.1% vs 58.5%) and fewer had access to predialysis nephrology care (60.8% vs 64.1%); the rates of heart failure and immobility varied, but not in a consistent pattern, by HSA dialysis density. The mean (SD) facility density was 4.1 (1.89) centers per 100 000 population in the most dialysis-dense HSAs. Compared with patients in HSAs with a mean of 1.0 per 100 000 population, the odds of hemodialysis initiation at eGFR greater than 10 mL/min/1.73 m2 were 1.07 (95% CI, 1.03-1.11) for patients in the densest HSAs, and compared with HSAs with 0 facilities, the odds of early hemodialysis initiation were 1.06 (95% CI, 1.02-1.10) for patients in the densest HSAs.

Conclusions and Relevance

In this cross-sectional study of USRDS- and HSA-level data, HSA dialysis density was associated with early hemodialysis initiation.

Physician Variation and the Impact of Payment Model in Cardiac Imaging

BACKGROUND

The influence of fee-for-service reimbursement on cardiac imaging has not been compared with other payment models. Furthermore, variation in ordering practices is not well understood.

METHODS AND RESULTS

This retrospective, population-based cohort study using linked administrative data from Alberta, Canada included adults with chronic heart disease (atrial fibrillation, coronary artery disease, and heart failure) seen by cardiac specialists for a new outpatient consultation April 2012 to December 2018. Generalized linear mixed-effects models estimated the association of payment model (including the ability to bill to interpret imaging tests) and the use of cardiac imaging and quantified variation in cardiac imaging. Among 31 685 adults seen by 308 physicians at 136 sites, patients received an observed mean of 0.67 (95% CI, 0.67-0.68) imaging tests per consultation. After adjustment, patients seeing fee-for-service physicians had 2.07 (95% CI, 1.68-2.54) and fee-for-service physicians with ability to interpret had 2.87 (95% CI, 2.16-3.81) times the rate of receiving a test than those seeing salaried physicians. Measured patient, physician, and site effects accounted for 31% of imaging variation and, following adjustment, reduced unexplained site-level variation 40% and physician-level variation 29%.

CONCLUSIONS

We identified substantial variation in the use of outpatient cardiac imaging related to physician and site factors. Physician payment models have a significant association with imaging use. Our results raise concern that payment models may influence cardiac imaging practice. Similar methods could be applied to identify the source and magnitude of variation in other health care processes and outcomes.

Chronic hemodialysis: Evaluation of dialysis adequacy and mortality

Objective

Dialysis efficacy is one of the important issues in patients undergoing hemodialysis. This study aimed to determine the adequacy of dialysis with mortality and hospital admissions in patients undergoing hemodialysis.

Methods

This retrospective cohort study was conducted on patients who underwent dialysis. Dialysis adequacy was measured based on the Kt/V criterion. Age, sex, disease etiology, duration of dialysis, and access dialysis were evaluated.

Results

128 patients with a mean age of 61.48 ± 13.36 years were included in the study. 8 patients had a history of kidney transplantation. The mean dialysis time in the patients was 4.30 ± 3.39 years. The mean Kt/V in the patients was 1.40 ± 1.8 years. Of the 128 patients, 53 were hospitalized for cardiac or renal reasons. The number of fatalities was 9 cases out of 128. The cause of death in all the cases was heart problems. There was a statistically significant correlation between the adequacy of dialysis in terms of Kt/V and mortality, but it was not associated with hospitalization.

Conclusion

Inadequate dialysis in terms of Kt/V is likely to increase the rate of mortality among dialysis patients.

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Dialysis efficacy is one of the important issues in patients undergoing hemodialysis.

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Inadequate dialysis in terms of Kt/V is likely to increase the rate of mortality among dialysis patient.

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The findings showed that there was no significant correlation between the dialysis adequacy and hospitalization.

Association between the risk of death and serum calcium, phosphate, and intact parathyroid hormone levels in older patients undergoing maintenance hemodialysis: a cohort study in Beijing

BACKGROUND

The number of patients ⩾65 years who require maintenance hemodialysis (MHD) is increasing. Although reduced bone turnover in older patients receiving hemodialysis, as reflected by lower serum intact parathyroid hormone (iPTH) and phosphate (P) levels, has been reported, focus on the association between abnormal bone metabolism and the risk of death in older patients receiving MHD has been limited.

METHODS

We retrospectively examined data from the Beijing Hemodialysis Quality Control and Improvement Center for 1410 older patients who underwent hemodialysis from 1 January 2012 to 31 December 2016. Baseline, time-dependent (TD) Cox proportional hazards models and Kaplan-Meier analyses were used to evaluate the association between the markers of mineral and bone disorder (MBD) [calcium (Ca), P, and iPTH] and survival. The Kidney Disease: Improving Global Outcomes (KDIGO) target ranges were included as reference values.

RESULTS

Serum P levels >2.49 mmol/l increased the risk of all-cause death [hazard ratio (HR): 1.46; 95% confidence interval (CI): 1.04-2.07; p = 0.030] and cardiovascular death (HR: 2.01; 95%CI: 1.21-3.34; p = 0.007); iPTH levels >600 pg/ml increased the risk of cardiovascular death (HR: 1.95; 95%CI: 1.20-3.15; p = 0.007). Baseline results and TD Cox analyses were similar. All three MBD parameters were within the respective target ranges at least once during the follow-up period in 399 (28.3%) patients, and these patients had better survival rates than those who achieved two of the three target ranges (715/1410 patients; 50.7%); those who achieved one or no target range (296/1410; 21.0%) had the lowest survival rate (all-cause death: log-rank chi square = 83.96, p < 0.001; cardiovascular death: log-rank chi square = 47.06, p < 0.001).

CONCLUSION

Older patients undergoing MHD who achieved the KDIGO target levels for any two or three MBD parameters had lower risks of all-cause and cardiovascular death.

Precision medicine approach to dialysis including incremental and decremental dialysis regimens

PURPOSE OF REVIEW

Conventional standardization of haemodialysis for treatment of end-stage kidney disease (ESKD) is predicated upon the fixed construct of one disease stage and one patient category. Increasingly recognized are subgroups of patients for whom less-intensive haemodialysis, such as incremental or decremental haemodialysis, could be employed.

RECENT FINDINGS

Almost 30% of patients with incident ESKD have clinical and residual kidney function (RFK) parameters that could accommodate less-intensive haemodialysis. In one study, patients with incident ESKD and substantial RKF treated with low-dose haemodialysis had similar mortality rate as those treated with standard-dose haemodialysis, adding to the evidence that endogenous kidney function -- when present -- can complement less-intensive haemodialysis schedules. Hazards related to incremental haemodialysis include insidious development of fluid overload and higher rates of fluid removal. Finally, deintensification of haemodialysis treatment could be employed in patients with ESKD who seek conservative care.

SUMMARY

A shift in approach to ESKD from a dichotomous frame -- disease presence versus absence -- to stages of dialysis-dependent kidney disease, each stage associated with attuned haemodialysis intensity, has been proposed. Haemodialysis standardization and personalization -- often considered mutually exclusive -- can be combined in incremental haemodialysis. Data from ongoing and future randomized clinical trials, comparing less-intensive with standard haemodialysis schedules, are required to change practice.

Exploring the choices and outcomes of older patients with advanced kidney disease

A lack of data on patient choices and outcomes at the time of pre-dialysis planning limits meaningful shared decision making, particularly in older frailer patients. In this large retrospective cohort study of patients aged over 70 seen by the pre-dialysis clinic (2004–2016) of a large single centre in the United Kingdom (1,216 patients), age, sex, comorbidity, poverty and frailty were used to predict choice of renal replacement therapy (RRT) over maximum conservative management (MCM). The impact of patient choice of RRT versus MCM was used to predict survival from the time of choice using multivariable Cox proportional hazards regression. Older age, female sex, greater poverty and greater frailty were associated with choosing MCM, whilst comorbidity had no significant impact on choice. At 5 years of follow up, 49% of all patients had died without receiving RRT. Over 70% of the patients choosing MCM died with better kidney function than the median level at which those starting RRT initiated treatment. Frailty and age were better predictors of survival than comorbidity and in patients with at least moderate frailty, RRT offered no survival benefit over MCM. In conclusion, analysing outcomes from the time of choice may improve shared decision making. Frailty should be routinely assessed and collected and further work may help predict which patients are unlikely to survive or progress to end stage renal disease and may not need to be burdened with making a pre-dialysis choice.

Narrative Review of Incremental Hemodialysis

The prescription of hemodialysis (HD) in patients with incident end-stage kidney disease (ESKD) is fundamentally empirical. The abrupt transition from nondialysis chronic kidney disease (CKD) to thrice-weekly in-center HD of much the same dialysis intensity as in those with prevalent ESKD underappreciates the progressive nature of kidney disease whereby the decline in renal function has been gradual and ongoing-including at the time of HD initiation. Adjuvant pharmacologic treatment (i.e., diuretics, acid buffers, potassium binders), coupled with residual kidney function (RKF), can complement an initial HD regimen of lower intensity. Barriers to less intensive HD in incident ESKD include risk of inadequate clearance of uremic toxins due to variable and unexpected loss of RKF, lack of patient adherence to assessments of RKF or adjustment of HD intensity, increased burden for all stakeholders in the dialysis units, and negative financial repercussions. A stepped dialysis regimen with scheduled transition from time-delineated twice-weekly HD to thrice-weekly HD could represent an effective and safe strategy to standardize incremental HD in patients with CKD transitioning to early-stage ESKD. Patients' adherence and survival as well as other clinical outcomes should be rigorously evaluated in clinical trials before large-scale implementation of different incremental schedules of HD. This review discusses potential benefits of and barriers to alternative dialysis regimens in patients with incident ESKD, with emphasis on twice-weekly HD with pharmacologic therapy, and summarizes in-progress clinical trials of incremental HD schedules.

Predicting Residual Function in Hemodialysis and Hemodiafiltration-A Population Kinetic, Decision Analytic Approach

In this study, we introduce a novel framework for the estimation of residual renal function (RRF), based on the population compartmental kinetic behavior of beta 2 microglobulin (B2M) and its dialytic removal. Using this model, we simulated a large cohort of patients with various levels of RRF receiving either conventional high-flux hemodialysis or on-line hemodiafiltration. These simulations were used to estimate a novel population kinetic (PK) equation for RRF (PK-RRF) that was validated in an external public dataset of real patients. We assessed the performance of the resulting equation(s) against their ability to estimate urea clearance using cross-validation. Our equations were derived entirely from computer simulations and advanced statistical modeling and had extremely high discrimination (Area Under the Curve, AUC 0.888–0.909) when applied to a human dataset of measurements of RRF. A clearance-based equation that utilized predialysis and postdialysis B2M measurements, patient weight, treatment duration and ultrafiltration had higher discrimination than an equation previously derived in humans. Furthermore, the derived equations appeared to have higher clinical usefulness as assessed by Decision Curve Analysis, potentially supporting decisions for individualizing dialysis prescriptions in patients with preserved RRF.

Lab-based and diagnosis-based chronic kidney disease recognition and staging concordance

BACKGROUND

Chronic kidney disease (CKD) is often under-recognized and poorly documented via diagnoses, but the extent of under-recognition is not well understood among Medicare beneficiaries. The current study used claims-based diagnosis and lab data to examine patient factors associated with clinically recognized CKD and CKD stage concordance between claims- and lab-based sources in a cohort of Medicare beneficiaries.

METHODS

In a cohort of fee-for-service (FFS) beneficiaries with CKD based on 2011 labs, we examined the proportion with clinically recognized CKD via diagnoses and factors associated with clinical recognition in logistic regression. In the subset of beneficiaries with CKD stage identified from both labs and diagnoses, we examined concordance in CKD stage from both sources, and factors independently associated with CKD stage concordance in logistic regression.

RESULTS

Among the subset of 206,036 beneficiaries with lab-based CKD, only 11.8% (n = 24,286) had clinically recognized CKD via diagnoses. Clinical recognition was more likely for beneficiaries who had higher CKD stages, were non-elderly, were Hispanic or non-Hispanic Black, lived in core metropolitan areas, had multiple chronic conditions or outpatient visits in 2010, or saw a nephrologist. In the subset of 18,749 beneficiaries with CKD stage identified from both labs and diagnoses, 70.0% had concordant CKD stage, which was more likely if beneficiaries were older adults, male, lived in micropolitan areas instead of non-core areas, or saw a nephrologist.

CONCLUSIONS

There is significant under-diagnosis of CKD in Medicare FFS beneficiaries, which can be addressed with the availability of lab results.

Association Between the Publication of the Initiating Dialysis Early and Late Trial and the Timing of Dialysis Initiation in Canada

IMPORTANCE

Published in 2010, the Initiating Dialysis Early and Late (IDEAL) randomized clinical trial, which randomized patients with an estimated glomerular filtration rate (GFR) between 10 and 15 mL/min/1.73 m2 to planned initiation of dialysis with an estimated GFR between 10 and 14 mL/min/1.73 m2 (early start) or an estimated GFR between 5 and 7 mL/min/1.73 m2 (late start), concluded that early initiation was not associated with improved survival or clinical outcomes.

OBJECTIVE

To assess the association between the IDEAL trial results and the proportion of early dialysis starts over time.

DESIGN, SETTING, AND PARTICIPANTS

This interrupted time series analysis used data from the Canadian Organ Replacement Register to study adult (≥18 years of age) patients with incident chronic dialysis between January 1, 2006, and December 31, 2015, in Canada, which has a universal health care system. Patients from the province of Quebec were excluded because its privacy laws preclude submission of deidentified data without first-person consent. The patients included in the study (n = 28 468) had at least 90 days of nephrologist care before starting dialysis and a recorded estimated GFR at dialysis initiation. Data analyses were performed from November 2016 to January 2019.

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of early dialysis starts (estimated GFR >10.5 mL/min/1.73 m2), and the secondary outcomes included the proportions of acute inpatient dialysis starts, patients who started dialysis using a home modality, and patients receiving hemodialysis who started with an arteriovenous access. Measures included the trend prior to the IDEAL trial publication, the change in this trend after publication, and the immediate consequence of publication.

RESULTS

The final cohort comprised 28 468 patients, of whom 17 342 (60.9%) were male and the mean (SD) age was 64.8 (14.6) years. Before the IDEAL trial, a statistically significant increasing trend was observed in the monthly proportion of early dialysis starts (adjusted rate ratio, 1.002; 95% CI, 1.001-1.004; P = .004). After the IDEAL trial, an immediate decrease was observed in the proportion of early dialysis starts (rate ratio, 0.874; 95% CI, 0.818-0.933; P < .001), along with a statistically significant change in trend between the pretrial and posttrial periods (rate ratio, 0.994; 95% CI, 0.992-0.996; P < .001). No statistically significant differences were found in acute inpatient dialysis initiations, the proportion of patients receiving home dialysis as the initial modality, or the proportion of arteriovenous access creation at hemodialysis initiation after the IDEAL trial publication.

CONCLUSIONS AND RELEVANCE

The publication of the IDEAL trial appeared to be associated with an immediate and meaningful change in the timing of dialysis initiation in Canada.

Influence of Sex on the Progression of Chronic Kidney Disease

The role that sex plays in the development and progression of chronic kidney disease remains a subject of controversy. The lack of clarity in this important area reflects complex interactions between biological factors and cultural and socioeconomic influences that impact the relationship between sex and renal disease. Certainly, additional observational studies are indicated; however, innovative approaches are required to isolate biological processes from cultural influences. Despite these limitations, available data suggest that the progression of renal disease is slower in women than in men and that this sexual dimorphism is primarily due to direct actions of sex hormones on cellular metabolism. The extent to which differences in lifestyle factors between the sexes influence sexual dimorphism in the progression of chronic kidney disease remains to be elucidated.

Duration of delayed graft function and outcomes after kidney transplantation from controlled donation after circulatory death donors: a retrospective study

The impact of the duration of delayed graft function (DGF) on graft survival is poorly characterized in controlled donation after circulatory death (DCD) donor kidney transplantation. A retrospective analysis was performed on 225 DCD donor kidney transplants between 2011 and 2016. When patients with primary nonfunction were excluded (n = 9), 141 recipients (65%) had DGF, with median (IQR) duration of dialysis dependency of 6 (2-11.75) days. Longer duration of dialysis dependency was associated with lower estimated glomerular filtration rate at 1 year, and a higher rate of acute rejection. On Kaplan-Meier analysis, the presence of DGF was associated with lower graft survival (log-rank test P = 0.034), though duration of DGF was not (P = 0.723). However, multivariable Cox regression analysis found that only acute rejection was independently associated with lower graft survival [HR (95% CI) 4.302 (1.617-11.450); P = 0.003], whereas the presence of DGF and DGF duration were not. In controlled DCD kidney transplantation, DGF duration itself may not be independently associated with graft survival; rather, it may be that acute rejection associated with prolonged DGF is the poor prognostic factor.

Chinese Herbal Medicine Improves the Long-Term Survival Rate of Patients With Chronic Kidney Disease in Taiwan: A Nationwide Retrospective Population-Based Cohort Study

Background and purpose: Chinese herbal medicine (CHM) is frequently applied in conjunction with western pharmacotherapy to relieve symptoms in patients with CKD. However, evidence-based research into the effectiveness of CHM use as applied to treat CKD is limited and warrants further investigation. The aim of this study is to assess whether adjunctive treatment with CHM affected survival rate of CKD patients undergoing conventional western medical management.

Methods: A total of 14,718 CKD patients, including 6,958 CHM users and 7,760 non-CHM users, were recruited from the Longitudinal Health Insurance Database 2000, a sub-dataset of the National Health Insurance Research Database, to conduct this study. Demographic characteristics, including sex, age, job type, residential area, and comorbidity were considered as covariates to adjust the analysis. A network analysis of treatments, including with herbal formulas and single herbs, was performed to investigate the core patterns of CHM use for the treatment of CKD patients. The Kaplan-Meier method was used to determine the survival rate between CHM and non-CHM groups.

Results: After matching for sex and age, there were 550 subjects in both the CHM and non-CHM cohorts. Other than presence of diabetes (adjusted OR = 0.57, p < 0.001) and urinary tract infection (adjusted OR = 0.69, p < 0.05), sex, age, job type, area of residence, and other comorbidities indicated no special preference for CHM use among subjects. Salvia miltiorrhiza Bunge (SM) and Ji-Sheng-Shen-Qi-Wan (JSSQW) were the most frequent single herb and formula, respectively, prescribed for patients with CKD. The most frequent CHM combination between herbs and formulas was JSSQW, associated with Rheum officinale Baill. (RO), SM and Astragalus membranaceus (Fisch.) Bunge (AM). The long-term survival rate demonstrated significant benefits for CHM users within a 12-year follow-up period (P < 0.004).

Conclusion: This nationwide retrospective cohort study provides valuable insight into the characteristics and prescription patterns of CHM usage in CKD patients. JSSQW associated with RO, SM, and AM is the most common CHM prescription. CHM improves long-term survival in patients with CKD, suggesting that CHM is an effective adjuvant therapy for CKD.