Timing of peritoneal dialysis initiation and mortality: analysis of the Canadian Organ Replacement Registry

Risk factors for early death in urgent-start peritoneal dialysis patients: A multicenter retrospective cohort study

BACKGROUND

Assess risk factors for early death in patients who underwent urgent-start peritoneal dialysis (USPD).

METHODS

Patients who initiated USPD in five peritoneal dialysis centers from 2013 to 2019 were screened in this multicenter retrospective cohort study. Risk factors for all-cause mortality within 3 months were explored.

RESULTS

A total of 1265 USPD patients with 43 early deaths were included. Cox regression analyses showed that age older than 60 years (hazard ratio [HR], 3.054; 95% CI [1.597, 5.842]; p = 0.001), albumin less than 30 g/L (HR, 2.234; 95%CI [1.207, 4.136]; p = 0.011), blood glucose greater than 7 mmol/L (HR, 2.766; 95%CI [1.477, 5.180]; p = 0.001), higher estimated glomerular filtration rate (eGFR; HR, 1.121; 95%CI [1.071, 1.172]; p = 0.000), and poor stages of heart failure (class IV compared with class 0-I; HR, 5.165; 95%CI [2.544, 10.486]; p = 0.000) were independent predicting factors for early death.

CONCLUSIONS

Risk factors for early death were older age, hypoproteinemia, hyperglycemia, higher eGFR, and severe heart failure.

Timing of dialysis initiation to reduce mortality and cardiovascular events in advanced chronic kidney disease: nationwide cohort study

OBJECTIVE

To identify the optimal estimated glomerular filtration rate (eGFR) at which to initiate dialysis in people with advanced chronic kidney disease.

DESIGN

Nationwide observational cohort study.

SETTING

National Swedish Renal Registry of patients referred to nephrologists.

PARTICIPANTS

Patients had a baseline eGFR between 10 and 20 mL/min/1.73 m2 and were included between 1 January 2007 and 31 December 2016, with follow-up until 1 June 2017.

MAIN OUTCOME MEASURES

The strict design criteria of a clinical trial were mimicked by using the cloning, censoring, and weighting method to eliminate immortal time bias, lead time bias, and survivor bias. A dynamic marginal structural model was used to estimate adjusted hazard ratios and absolute risks for five year all cause mortality and major adverse cardiovascular events (composite of cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) for 15 dialysis initiation strategies with eGFR values between 4 and 19 mL/min/1.73 m2 in increments of 1 mL/min/1.73 m2. An eGFR between 6 and 7 mL/min/1.73 m2 (eGFR6-7) was taken as the reference.

RESULTS

Among 10 290 incident patients with advanced chronic kidney disease (median age 73 years; 3739 (36%) women; median eGFR 16.8 mL/min/1.73 m2), 3822 started dialysis, 4160 died, and 2446 had a major adverse cardiovascular event. A parabolic relation was observed for mortality, with the lowest risk for eGFR15-16. Compared with dialysis initiation at eGFR6-7, initiation at eGFR15-16 was associated with a 5.1% (95% confidence interval 2.5% to 6.9%) lower absolute five year mortality risk and 2.9% (0.2% to 5.5%) lower risk of a major adverse cardiovascular event, corresponding to hazard ratios of 0.89 (95% confidence interval 0.87 to 0.92) and 0.94 (0.91 to 0.98), respectively. This 5.1% absolute risk difference corresponded to a mean postponement of death of 1.6 months over five years of follow-up. However, dialysis would need to be started four years earlier. When emulating the intended strategies of the Initiating Dialysis Early and Late (IDEAL) trial (eGFR10-14 v eGFR5-7) and the achieved eGFRs in IDEAL (eGFR7-10 v eGFR5-7), hazard ratios for all cause mortality were 0.96 (0.94 to 0.99) and 0.97 (0.94 to 1.00), respectively, which are congruent with the findings of the randomised IDEAL trial.

CONCLUSIONS

Very early initiation of dialysis was associated with a modest reduction in mortality and cardiovascular events. For most patients, such a reduction may not outweigh the burden of a substantially longer period spent on dialysis.

Early initiation of PD therapy in elderly patients is associated with increased risk of death

Background

The effect of early initiation of dialysis on outcomes of patients with end-stage renal disease (ESRD) remains controversial. We conducted this study to investigate the association between the timing of peritoneal dialysis (PD) initiation and mortality in different age groups.

Methods

In this single-centre cohort study, incident patients receiving PD from 1 January 2006 to 31 December 2016 were enrolled. Patients were categorized into three groups according to the estimated glomerular filtration rate (eGFR) at the initiation of PD, with early, mid and late initiation of PD defined as eGFR ≥7.5, 5–7.5 and <5 mL/min/1.73 m², respectively.

Results

A total of 2133 incident patients receiving PD were enrolled with a mean age of 47.1 years, 59.6% male and 25.3% with diabetes, of whom 1803 were young (age <65 years) and 330 were elderly (age ≥65 years). After multivariable adjustment, the overall and cardiovascular (CV) mortality risks for young patients receiving PD were not significantly different between these three groups. However, for elderly patients, early initiation of PD therapy was associated with increased risks of all-cause {hazard ratio [HR} 1.54 [95% confidence interval (CI) 1.06–2.25]} and CV [HR 2.07 (95% CI 1.24–3.48)] mortality compared with late initiation of PD, while no significant difference was observed in overall or CV mortality between the mid- and late-start groups.

Conclusions

No significant difference in mortality risk was found among the three levels of eGFR at PD therapy initiation in young patients, while early initiation of PD was associated with a higher risk of overall and CV mortality among elderly patients.

Higher eGFR at Dialysis Initiation Is Not Associated with a Survival Benefit in Children

BACKGROUND

Study findings suggest that initiating dialysis at a higher eGFR level in adults with ESRD does not improve survival. It is less clear whether starting dialysis at a higher eGFR is associated with a survival benefit in children with CKD.

METHODS

To investigate this issue, we performed a retrospective cohort study of pediatric patients aged 1-18 years who, according to the US Renal Data System, started dialysis between 1995 and 2015. The primary predictor was eGFR at the time of dialysis initiation, categorized as higher (eGFR>10 ml/min per 1.73 m²) versus lower eGFR (eGFR≤10 ml/min per 1.73 m²).

RESULTS

Of 15,170 children, 4327 (29%) had a higher eGFR (median eGFR, 12.8 ml/min per 1.73 m²) at dialysis initiation. Compared with children with a lower eGFR (median eGFR, 6.5 ml/min per 1.73 m²), those with a higher eGFR at dialysis initiation were more often white, girls, underweight or obese, and more likely to have GN as the cause of ESRD. The risk of death was 1.36 times higher (95% confidence interval, 1.24 to 1.50) among children with a higher (versus lower) eGFR at dialysis initiation. The association between timing of dialysis and survival differed by treatment modality-hemodialysis versus peritoneal dialysis (P<0.001 for interaction)-and was stronger among children initially treated with hemodialysis (hazard ratio, 1.56, 95% confidence interval, 1.39 to 1.75; versus hazard ratio, 1.07, 95% confidence interval, 0.91 to 1.25; respectively).

CONCLUSIONS

In children with ESRD, a higher eGFR at dialysis initiation is associated with lower survival, particularly among children whose initial treatment modality is hemodialysis.

Association between timing of peritoneal dialysis initiation and mortality in end-stage renal disease

Despite the widespread use of chronic dialysis for end-stage renal disease (ESRD), there is no consensus on the optimal timing of initiating renal replacement therapy. Over the past decade, a worldwide trend toward increasing glomerular filtration rate at the initiation of dialysis has been noted. However, available data indicate that early dialysis has no survival benefit or is harmful. Peritoneal dialysis (PD) is one alternative for ESRD and has potential survival factors different from those of hemodialysis. The association between the timing of PD initiation and survival is unclear. This review examines the effect of the timing of dialysis on clinical outcomes in PD patients.

Timing of Dialysis Initiation and Mortality Risk in Chronic Kidney Disease: A Meta-Analysis

The optimal time of dialysis initiation among patients with chronic kidney disease (CKD) is unclear in recent years. We performed a meta-analysis to assess the association of early vs. late initiation of dialysis with estimated glomerular filtration rate. PUBMED, EMBASE, the Cochrane Library, and article reference lists were searched for relevant observational trials. A pooled hazard ratio (HR) with 95% CI was used to estimate the mortality risk. Twenty-six cohort studies and one randomized controlled trial were identified. Early start of dialysis was associated with the increased risk of mortality (HR = 1.23, 95% CI: 1.04-1.43) compared with late start of dialysis. In the subgroup analysis, age younger than 65 years at the early start of dialysis demonstrated higher mortality (HR = 1.20, 95% CI: 1.05-1.35) than the late start. Compared with peritoneal dialysis, the pooled HR with HD was 1.25 (95% CI: 1.17-1.34). Early start of dialysis increased the mortality risk compared with late start among patients with CKD.

Measured Glomerular Filtration Rate at Dialysis Initiation and Clinical Outcomes of Indian Peritoneal Dialysis Patients

The optimal time for dialysis initiation remains controversial. Studies have failed to show better outcomes with early initiation of hemodialysis; even a few had shown increased adverse outcomes including poorer survival. Few studies have examined the same in patients on peritoneal dialysis (PD). Measured glomerular filtration rate (mGFR) not creatinine-based estimated GFR is recommended as the measure of kidney function in end-stage renal disease (ESRD) patients. The objective of this observational study was to compare the outcomes of Indian patients initiated on PD with different residual renal function (RRF) as measured by 24-h urinary clearance method. A total of 352 incident patients starting on chronic ambulatory PD as the first modality of renal replacement therapy were followed prospectively. Patients were categorized into three groups as per mGFR at the initiation of PD (≤5, >5-10, and >10 ml/min/1.73 m2). Patient survival and technique survival were compared among the three groups. Patients with GFR of ≤5 ml/min/1.73 m2 (hazard ratio [HR] - 3.42, 95% confidence interval [CI] - 1.85-6.30, P = 0.000) and >5-10 ml/min/1.73 m2 (HR - 2.16, 95% CI - 1.26-3.71, P = 0.005) had higher risk of mortality as compared to those with GFR of >10 ml/min/1.73 m2. Each increment of 1 ml/min/1.73 m2 in baseline GFR was associated with 10% reduced risk of death (HR - 0.90, 95% CI - 0.85-0.96, P = 0.002). Technique survival was poor in those with an initial mGFR of ≤5 ml/min/1.73 m2 as compared to other categories. RRF at the initiation was also an important factor predicting nutritional status at 1 year of follow-up. To conclude, initiation of PD at a lower baseline mGFR is associated with poorer patient and technique survival in Indian ESRD patients.

The Use of Incremental Peritoneal Dialysis in a Large Contemporary Peritoneal Dialysis Program

BACKGROUND

The use of an incremental peritoneal dialysis (PD) strategy in a large contemporary patient population has not been described.

OBJECTIVE

We report the use of this strategy in clinical practice, the prescriptions required, and the clearances achieved in a large center which has routinely used this approach for more than 10 years.

DESIGN

This is a cross-sectional observational study.

SETTING

A single large Canadian academic center.

PATIENTS

This study collected data on 124 prevalent PD patients at a single Canadian academic center.

METHODS AND MEASUREMENTS

The proportion of patients who achieve the clearance target on a low clearance or incremental PD prescription; the actual PD prescriptions and consequent total, peritoneal, and renal urea clearances [Kt/V] achieved; and patient and technique survival and peritonitis rate in comparison with national and international reports.

RESULTS

Of the 124 prevalent PD patients in this PD unit, 106 (86%) were achieving the Kt/V target, and of these, 54 (44% of all patients) were doing so using incremental PD prescriptions. Fifty of these incremental PD patients were using automated PD (APD) with either no day dwell (68%) or less than 7 days a week treatment (12%) or both (20%). Patient survival in our PD unit was not different from that reported in Canada as a whole. Peritonitis rates were better than internationally recommended standards.

LIMITATIONS

This is an observational study with no randomized control group.

CONCLUSIONS

Incremental PD is feasible in a contemporary PD population treated mainly with APD. Almost half of the patients were able to achieve clearance targets while receiving less onerous and less costly low clearance prescriptions. We suggest that incremental PD should be widely used as a cost-effective strategy in PD.

Patient characteristics and risk factors of early and late death in incident peritoneal dialysis patients

This study was conducted to identify key patient characteristics and risk factors for peritoneal dialysis (PD) mortality in terms of different time-point of death occurrence. The incident PD patients from January 1, 2006 to December 31, 2013 in our PD center were recruited and followed up until December 31, 2015. Patients who died in the early period (the first 3 months) were older, had higher neutrophil to lymphocyte ratio (N/L), serum phosphorus, and uric acid level, and had lower diastolic pressure, hemoglobin, serum albumin, and calcium levels. After adjustment of gender, age, and PD inception, higher N/L level [hazard ratio (HR) 1.115, P = 0.006], higher phosphorus lever (HR 1.391, P < 0.001), lower hemoglobin level (HR 0.596, P < 0.001), and lower serum albumin level (HR 0.382, P = 0.017) were risk factors for early mortality. While, presence of diabetes (HR 1.627, P = 0.001), presence of cardiovascular disease (HR 1.847, P < 0.001) and lower serum albumin level (HR 0.720, P = 0.023) were risk factors for late mortality (over 24 months). In conclusion, patient characteristics and risk factors associated with early and late mortality in incident PD patients were different, which indicated specific management according to patient characteristics at the initiation of PD should be established to improve PD patient survival.

Timing of start of dialysis in diabetes mellitus patients: a systematic literature review

BACKGROUND

Diabetes mellitus is a frequent cause of the need for renal replacement therapy (RRT). Historically, RRT was started earlier in patients with diabetes, in an attempt to prevent complications of uraemia and diabetes. We did a systematic review to find support for this earlier start of dialysis in patients with versus without diabetes.

METHODS

The MEDLINE, EMBASE and CENTRAL databases were searched for articles about the timing of dialysis initiation in (subgroups of) patients with diabetes and CKD Stage 5.

RESULTS

A total of 340 papers were screened and 11 papers were selected to be reviewed. Only three studies showed data of at least one subgroup of patients with diabetes. Two observational studies concluded that start of dialysis with a higher estimated glomerular filtration rate (eGFR) is beneficial with regard to survival, one did not find a difference and six observational studies concluded that start of dialysis with a lower eGFR is associated with better survival in patients with diabetes. The effect of timing of initiation of dialysis did not differ between patients with versus without diabetes. Lastly, one randomized controlled trial (two papers) reported that there was no difference in survival between start at higher versus lower eGFR overall and a P-value for the interaction with diabetes of P = 0.63, indicating no difference between patients with versus without diabetes with regard to the timing of start of dialysis and subsequent mortality on dialysis.

CONCLUSIONS

There is no difference between early (eGFR) and late (lower eGFR) start of RRT with regard to mortality in patients with versus without diabetes. RRT should thus be initiated based on the same criteria in all patients, irrespective of the presence or absence of diabetes.

When to initiate renal replacement therapy: The trend of dialysis initiation

The timing of renal replacement therapy for patients with end-stage renal disease has been subject to considerable variation. The United States Renal Data System shows an ascending trend of early dialysis initiation until 2010, at which point it decreased slightly for the following 2 years. In the 1990s, nephrologists believed that early initiation of dialysis could improve patient survival. Based on the Canadian-United States Peritoneal Dialysis study, the National Kidney Foundation Dialysis Outcomes Quality Initiative recommended that dialysis should be initiated early. Since 2001, several observational studies and 1 randomized controlled trial have found no beneficial effect when patients were placed on dialysis early. In contrast, they found that an increase in mortality was associated with early dialysis initiation. The most recent dialysis initiation guidelines recommend that dialysis should be initiated at an estimated glomerular filtration rate (eGFR) of greater than or equal to 6 mL/min per 1.73 m(2). Nevertheless, the decision to start dialysis is mainly based on a predefined eGFR value, and no convincing evidence has demonstrated that patients would benefit from early dialysis initiation as indicated by the eGFR. Even today, the optimal dialysis initiation time remains unknown. The decision of when to start dialysis should be based on careful clinical evaluation.

Canadian Organ Replacement Register (CORR): reflecting the past and embracing the future

INTRODUCTION

The Canadian Organ Replacement Register (CORR) is the only Canadian information system on kidney and extra-kidney organ failure and transplantation in Canada. CORR's mandate is to record and analyze the level of activity and outcomes of vital organ transplantation and treatment of end stage kidney disease using dialysis, either hemodialysis or peritoneal dialysis, activities across Canada. The Canadian Organ Replacement Register was officially launched in 1987, and it included transplantation of extra-renal vital organs (liver, heart, lung, pancreas, bowel), in addition to renal transplantation and replacement therapy, with new financial support from the provinces.

OBJECTIVE

This manuscript describes the process of data acquisition and reporting, focusing on the patients with end stage kidney disease on dialysis, with data reported from the 2014 CORR Annual Data Report and the Center-Specific Reports on Clinical Measures.

METHODS

CORR is currently housed in the Canadian Institute for Health Information and collects data from hospital dialysis programs, regional transplant programs, organ procurement organizations and kidney dialysis services offered at independent health facilities. Data on patients is collected by completion of survey forms for each patient at the start of dialysis or receiving a transplant, using the Initial Registration form, and yearly follow up forms, which collects data on the status of the patient as of October 31(st).

RESULTS

The incident rate per million population (RPMP) has remained stable with the exception of the 65+ age group with has experience a modest decrease since 2001. However, there has been an increasing prevalence of ESKD diagnoses, with the highest rate per million population (RPMP) amongst the age group 65+ years. This is likely attributed to gradual improving patient survival. Between 2003 and 2012, nearly 90% of dialysis patients younger than <18 and 26% of patients 75+ years survived for at least five years.

CONCLUSION

As the number of people treated for end-stage organ failure grows, so does the importance of understanding their treatment and outcomes. In 2014, CORR continues to evolve and support the important information need to advance ESRD research and clinical practice.

Variation in the level of eGFR at dialysis initiation across dialysis facilities and geographic regions

BACKGROUND AND OBJECTIVES

The relative influence of facilities and regions on the timing of dialysis initiation remains unknown. The purpose of the study is to determine the variation in eGFR at dialysis initiation across dialysis facilities and geographic regions in Canada after accounting for patient-level factors (case mix).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In total, 33,263 dialysis patients with an eGFR measure at dialysis initiation between January of 2001 and December of 2010 representing 63 dialysis facilities and 14 geographic regions were included in the study. Multilevel models and intraclass correlation coefficients were used to evaluate the variation in timing of dialysis initiation by eGFR at the patient, facility, and geographic levels.

RESULTS

The proportion initiating dialysis with an eGFR≥10.5 ml/min per 1.73 m(2) was 35.3%, varying from 20.1% to 57.2% across geographic regions and from 10% to 67% across facilities. In an unadjusted, intercept-only linear model, 90.7%, 6.6%, and 2.7% of the explained variability were attributable to patient, facility, and geography, respectively. After adjustment for patient and facility factors, 96.9% of the explained variability was attributable to patient case mix, 3.1% was attributable to the facility, and 0.0% was attributable to the geographic region. These findings were consistent when the eGFR was categorized as a binary variable (≥10.5 ml/min per 1.73 m(2)) or in an analysis limited to patients with >3 months of predialysis care.

CONCLUSIONS

Patient characteristics accounted for the majority of the explained variation regarding the eGFR at the initiation of dialysis. There was a small amount of variation at the facility level and no variation among geographic regions that was independent of patient- and facility-level factors.