Early outcomes of peritoneal dialysis in a middle-income country: A retrospective cohort study of a large dialysis network in Colombia.

BACKGROUND: The first year of dialysis is critical given the significant risk for complications following dialysis initiation. We analysed complications during the first year among incident peritoneal dialysis (PD) patients. METHODS: This retrospective cohort study comprised adult kidney failure patients starting PD in Baxter Renal Care Services in Colombia, receiving their first PD catheter between 1 January 2017 and 31 December 2020 and were followed up for up to 1 year. We analysed incidence, causes and factors associated with complications using logistic regression and transfer to haemodialysis (HD) using the Fine-Gray regression model. RESULTS: Among 4743 patients receiving their first PD catheter: 4628 (97.6%) of catheter implantations were successful; 377 (7.9%) patients experienced early complications. The incidence rate of complications during the year was 0.51 events per patient-year (95% CI: 0.48-0.54). Age, obesity and urgent start were associated with higher probability of complications after catheter implantation. The cumulative incidence of transfer to HD within 1 year of PD initiation was 10.1% [95% CI: 9.2-11.1%]. The hazard function for transfer to HD showed an accelerating pattern during the first month followed by progressive decrease during the first year. CONCLUSIONS: In this large population of incident PD patients, there is a high primary catheter placement success rate. Urgent start, age ≥65 years, obesity, centre size ≥150 PD patients and diabetes were risk factors associated with early complications. The follow-up of the cohort from day 1 of PD treatment showed that the risk for transfer to HD was higher during the first month.

Factors Associated with Hemodialysis Vascular Access Failure: A retrospective study in Colombia

Introduction: Vascular access (VA) remains a major source of morbidity for hemodialysis patients (HD). Few data sources adequately capture longitudinal patency of the VA. This study aimed to evaluate VA failure and its related factors in HD patients. Methods: A retrospective cohort study of 985 incident hemodialysis patients treated in clinics of BRCS in Colombia, from January 1rst ,2016, until December 3 of the same year, was done. The cohort's enrollment was on day 1 of HD, and with follow-up for up to 15 months. Association among a group of independent variables and time to failure of the VA was performed, and adjusted by baseline variables using a Cox regression model. Results: A total of 985 patients were included in the study, requiring 1774 procedures of vascular access during follow-up. The mean age was 61 ± 15.6 years. At day 1, 15 % were dialyzing with an arteriovenous fistula (AVF) or AVG; and at day 90, this proportion had increased to 70 %. The rate of vascular access procedure was 1.95 per patients-year, 95 % CI 1.86-2.04. The rate of vascular access failure was 0.66 per patients-year, 95 % CI 0.61-0.72. Risk factors for failure in AVF/AVG were age > 65 (p= 0.008), diabetes (p=0.019), female sex (p=0.002) rural housing (p<0.0001) and higher hemoglobin (p=0.021). Conclusions: Vascular access failure and the requirement for procedures associated with it are frequent in the dialysis population. Several risk factors, some of them modifiable, are related to vascular access failure.

Introducción: El acceso vascular (AV) sigue siendo una fuente importante de morbilidad para los pacientes en hemodiálisis (HD). Pocas fuentes de datos capturan adecuadamente la permeabilidad longitudinal del AV. Este estudio tiene como objetivo evaluar la falla del AV y los factores relacionados en pacientes en HD. Métodos: Se realizó un estudio de cohorte retrospectivo de 985 pacientes incidentes a hemodiálisis tratados en clínicas de BRCS en Colombia, entre el 1ro de enero de 2016, al 31 de diciembre de 2016. La incepción de la cohorte fue el día 1 de HD y con un seguimiento de hasta 15 meses. Se realizó la asociación entre un grupo de variables independientes y el tiempo hasta la falla del AV, asimismo se ajustó por variables basales mediante un modelo de regresión de Cox. Resultados: Se incluyeron en el estudio un total de 985 pacientes que requirieron 1774 procedimientos de AV durante el seguimiento. La edad media fue de 61 ± 15,6 años. En el día 1, el 15 % se dializaba con una fístula arteriovenosa (FAV) o injerto arteriovenoso (IAV); y al día 90, esta proporción había aumentado al 70 %. La tasa de procedimiento de acceso vascular fue de 1,95 por paciente-año, IC 95 % 1,86-2,04. La tasa de falla del AV fue de 0,66 por paciente-año, IC del 95 %: 0,61-0,72. Los factores de riesgo para falla del AV en FAV/IAV fueron edad > 65 años (p= 0,008), diabetes (p= 0,019), sexo femenino (p= 0,002), vivienda rural (p<0,0001) y hemoglobina elevada (p=0,021). Conclusión: La falla del acceso vascular y el requerimiento de procedimientos asociados a ella, son frecuentes en la población en diálisis. Varios factores de riesgo, algunos de ellos modificables, están relacionados con la falla del acceso vascular.

Medium Cutoff Versus High-Flux Hemodialysis Membranes and Clinical Outcomes: A Cohort Study Using Inverse Probability Treatment Weighting.

Rationale & Objective: This study investigated the effects on patients' outcomes of using medium cutoff (MCO) versus high-flux (HF) dialysis membranes. Study Design: A retrospective, observational, multicenter, cohort study. Setting & Participants: Patients aged greater than 18 years receiving hemodialysis at the Baxter Renal Care Services dialysis network in Colombia. The inception of the cohort occurred from September 1, 2017, to November 30, 2017, with follow-up to November 30, 2019. Exposure: The patients were divided into 2 cohorts according to the dialyzer used at the inception: (1) MCO membrane or (2) HF membrane. Outcomes: Primary outcomes were the hospitalization rate from any cause and hospitalization days per patient-year. Secondary outcomes were acute cardiovascular events and mortality rates from any cause and secondary to cardiovascular causes. Laboratory parameters were assessed throughout the 2-year follow-up period. Analytical Approach: Descriptive statistics were used to report population characteristics. Inverse probability of treatment weighting was applied to each group before analysis. All categorical variables were compared using Pearson's χ2 test, and continuous variables were analyzed with the t test. Baseline differences between groups with a value of >10% were considered clinically meaningful. Laboratory variables were measured at 5 consecutive time points. A between-patient effect was analyzed using a split-plot factorial analysis of variance. Results: The analysis included 1,098 patients, of whom 564 (51.3%) were dialyzed with MCO membranes and 534 (48.7%) with HF membranes. Patients receiving hemodialysis with MCO membranes had a lower all-cause hospitalization incidence rate (IR) per patient-year (IR = 0.93; 95% CI, 0.82-1.03) than those receiving hemodialysis with HF membranes (IR = 1.13; 95% CI, 0.96-1.30), corresponding to a significant incident rate ratio (MCO/HF) of 0.82 (95% CI, 0.68-0.99; P = 0.04). The frequency of nonfatal cardiovascular events showed statistical significance, with a lower incidence in the MCO group (incident rate ratio = 0.66; 95% CI, 0.46-0.96; P = 0.03). No statistically significant differences in all-cause time until death were observed (P = 0.48). Albumin levels were similar between the 2 dialyzer cohorts. Limitations: Despite the robust statistical analysis, there remains the possibility that unmeasured variables may still generate residual imbalance and, therefore, skew the results. Conclusions: The incidences of hospitalization and cardiovascular events in patients receiving hemodialysis were lower when dialyzed with MCO membranes than HF membranes. A randomized controlled trial would be desirable to confirm these results. Trial Registration: Clinical Trials.gov, ISRCTN12403265.

Technique failure in remote patient monitoring program in patients undergoing automated peritoneal dialysis: A retrospective cohort study.

BACKGROUND: Remote patient monitoring (RPM) programs in automated peritoneal dialysis (APD) allow clinical teams to be aware of many aspects and events of the therapy that occur in the home. The present study evaluated the association between RPM use and APD technique failure. METHODS: A retrospective, multicentre, observational cohort study of 558 prevalent adult APD patients included between 1 October 2016 and 30 June 2017 with follow-up until 30 June 2018 at Renal Therapy Services network in Colombia. Patients were divided into two cohorts based on the RPM use: APD-RPM (n = 148) and APD-without RPM (n = 410). Sociodemographic and clinical characteristics of all patients were summarized descriptively. A propensity score was used to create a pseudo-population in which the baseline covariates were well balanced. The association of RPM with technique failure was estimated adjusting for the competing events death and kidney transplant. RESULTS: Five hundred fifty-eight patients were analyzed. 26.5% had APD-RPM. In the matched sample comprising 148 APD-RPM and 148 APD-without RPM patients, we observed a lower technique failure rate of 0.08 [0.05-0.15] episodes per patient-year in APD-RPM versus 0.18 [0.12-0.26] in APD-without RPM cohort; incidence rate ratio = 0.45 95% confidence interval: [0.22-0.91], p-value = 0.03. CONCLUSIONS: The use of an RPM program in APD patients may be associated with a lower technique failure rate. More extensive and interventional studies are needed to confirm its potential benefits and to measure other patient-centered outcomes.

Dialysis Outcomes in a Middle-Income Country: An Updated Comparison of Patient Mortality between Hemodialysis and Peritoneal Dialysis.

INTRODUCTION: Comparisons of survival between dialysis modalities is of great importance to patients with kidney failure, their families, and healthcare systems. OBJECTIVE: This study's objective was to compare mortality of patients on chronic hemodialysis (HD) or peritoneal dialysis (PD) and identify variables associated with mortality. METHODS: This retrospective cohort study included adult incident patients with kidney failure treated with HD or PD by the Baxter Renal Care Services network in Colombia. The study was conducted between January 1, 2008, and December 31, 2013 (recruitment period), with follow-up until December 31, 2018. The outcome was the cumulative mortality rate at 1, 2, 3, 4, and 5 years. Propensity score matching (PSM) and the Gompertz parametric survival model were used to compare mortality in HD versus PD. RESULTS: The analysis included 12,499 patients, of whom 57.4% were on PD at inception. The overall mortality rate was 14.0 events per 100 patient-years (95% confidence interval [CI], 13.61-14.42). Using an intention-to-treat approach, crude mortality rates were significantly lower in patients receiving HD (HD: 12.3 deaths per 100 patient-years [95% CI, 11.7-12.8] vs. PD: 15.5 [14.9-16.1], p < 0.01). Using a Gompertz parametric survival model, dialysis modality was not significantly associated with mortality (hazard ratio HD vs. PD 1.0, 95% CI, 0.9-1.1). After PSM, the mortality cumulative incidence functions between HD and PD were not statistically significantly different (p = 0.88). CONCLUSIONS: The present study in a large cohort of incident dialysis patients with at least 5 years follow-up and using PSM methods showed no differences in cumulative mortality between HD and PD patients. This evidence from a middle-income country may facilitate the process of dialysis modality selection globally.

Peritoneal Dialysis Modality Failure in a Middle-Income Country: A Retrospective Cohort Study.

RATIONALE & OBJECTIVE: Technique failure in peritoneal dialysis (PD) remains one of the most critical challenges of this therapy and is associated with a significant increase in costs and morbidity. Our objective was to estimate the frequency of PD technique failure and identify factors associated with technique failure. STUDY DESIGN: A retrospective multicenter observational cohort study. SETTING & PARTICIPANTS: All adult patients initiating PD between January 1, 2010, and December 31, 2015, with follow-up until December 31, 2018, at the Renal Therapy Services network in Colombia. EXPOSURE & PREDICTORS: PD modality (continuous ambulatory PD and automated PD) and demographic and clinical characteristics. OUTCOMES: Technique failure, defined as a switch to hemodialysis lasting at least 30 days. ANALYTICAL APPROACH: Sociodemographic and clinical characteristics of all patients were summarized descriptively according to modality. We estimated the cumulative incidence of technique failure, and a flexible parametric survival model with competing risks was used to evaluate factors associated with this outcome. RESULTS: Among 6,452 patients meeting inclusion criteria, 67% were treated with continuous ambulatory PD. The cumulative incidence of technique failure within 1 year of PD initiation adjusting for competing risks was 6.9% (95% CI, 6.3%-7.6%); within 2 years, technique failure was 13.5% (95% CI, 12.6%-14.4%); and within 3 years, 19.6% (95% CI, 18.5%-20.7%). Female sex, larger center size, and higher Kt/V were associated with lower risk for modality change, whereas diabetes, history of major abdominal surgery, catheter implant technique (laparotomy and percutaneous techniques), obesity, and peritonitis were associated with a higher likelihood of technique failure. LIMITATIONS: Variables of distance to the center, use of icodextrin, and measures of outcomes reported by patients were not included. CONCLUSIONS: Technique failure is relatively uncommon in Colombia; catheter-related problems are the most frequent cause of technique failure. Best practices in catheter insertion could minimize the risk for this outcome.

Chronic Kidney Disease Progression and Transition Probabilities in a Large Preventive Cohort in Colombia.

BACKGROUND: Variability in chronic kidney disease (CKD) progression is a well-known phenomenon that underlines the importance of characterizing the said outcome in specific populations. Our objectives were to evaluate changes in the estimated glomerular filtration rate (eGFR) over time and determine the frequency of dialysis admission and factors associated with this outcome, to estimate the rate of program's loss-to-follow-up and the probability of transition between CKD stages over time. METHODS: The study type was an observational analytic retrospective cohort in patients treated in a CKD prevention program in Bogota, Colombia, between January 1, 2009, and December 31, 2013, with follow-up until December 31, 2018. Adult participants of 18 years of age or older with diagnosed CKD stages G3 or G4 were enrolled into a prevention program. For each patient, the rate of progression of CKD in ml/min/1.73 m2/year was estimated using the ordinary least-squares method. Dialysis initiation and program's loss-to-follow-up rates were calculated. Heat maps were used to present probabilities of transitioning between various CKD stages over time. Survival model with competing risks was used to evaluate factors associated with dialysis initiation. RESULTS: A total of 2752 patients met inclusion criteria and contributed with 14133 patient-years of follow-up and 200 dialysis initiation events, which represents a rate of 1.4 events per 100 patient-years (95% CI 1.2 to 1.6). The median change of the eGFR for the entire cohort was -0.47 ml/min/1.73 m2 per year, and in the diabetic population, it was -1.55 ml/min/1.73 m2 per year. The program's loss-to-follow-up rate was 2.6 events per 100 patient-years (95% CI 2.3 to 2.9). Probabilities of CKD stage transitions are presented in heat maps. Female sex, older age, baseline eGFR, and serum albumin were associated with lower risk of dialysis initiation while CKD etiology diabetes, cardiovascular disease history, systolic blood pressure, blood urea nitrogen, and LDL cholesterol were associated with a higher likelihood of dialysis initiation. CONCLUSIONS: A CKD secondary prevention program's key indicator is reported here, such as dialysis initiation, progression rate, and program drop-out; CKD progression appears to be correlated with diabetic status and timing of referral into the preventive program.

Expanded Hemodialysis and Its Effects on Hospitalizations and Medication Usage: A Cohort Study.

INTRODUCTION: Expanded hemodialysis (HDx) effectively removes large middle molecular uremic toxins (>25 kDa) while still retaining albumin, potentially reducing their adverse effects. We compare the clinical laboratory parameters, hospitalization rates, and medication use in a cohort of patients switched from high-flux HD to HDx. METHODS: This is a multicenter, observational cohort study of 81 adult patients, across 3 clinics, with end-stage kidney disease (ESKD) on chronic hemodialysis (HD). Patients received high-flux HD for at least 1 year and then switched to HDx and were followed up for 1 year. Patients were excluded if they discontinued therapy, changed provider, underwent kidney transplant, recovered kidney function, or changed to peritoneal dialysis, another dialyzer, or renal clinic. RESULTS: Twelve months after switching to HDx, the rate of hospitalization events per patient-year decreased from 0.77 (95% CI: 0.60-0.98, 61 events) to 0.71 (95% CI: 0.55-0.92, 57 events) (p = 0.6987). The hospital day rate per patient-year was significantly reduced from 5.94 days in the year prior to switching compared with 4.41 days after switching (p = 0.0001). The mean dose of erythropoiesis-stimulating agent (SC epoetin-α) and intravenous iron also significantly decreased (p = 0.0361 and p = 0.0003, respectively). CONCLUSION: Switching to HDx was associated with reductions in hospital day rate and medication use, suggesting HDx has the potential to reduce the burden of ESKD on patients and healthcare systems.

An initial evaluation of expanded hemodialysis on hospitalizations, drug utilization, costs, and patient utility in Colombia.

To examine new evidence linking expanded hemodialysis (HDx) using a medium cut-off (MCO) membrane with hospitalizations, hospital days, medication use, costs, and patient utility. This retrospective study utilized data from Renal Care Services medical records database in Colombia from 2017 to 2019. Clinics included had switched all patients from high flux hemodialysis (HD HF) to HDx and had at least a year of data on HD HF and HDx. Data included demographic characteristics, comorbidities, years on dialysis, hospitalizations, medication use, and quality of life measured by the 36 item and Short Form versions of the Kidney Disease Quality of Life survey at the start of HDx, and 1 year after HDx, which were mapped to EQ-5D utilities. Generalized linear models were run on the outcomes of interest with an indicator for being on HDx. Annual cost estimates were also constructed. The study included 81 patients. HDx was significantly associated with lower dosing of erythropoietin stimulating agents, iron, hypertension medications, and insulin. HDx was also significantly associated with lower hospital days per year (5.94 on HD vs. 4.41 on HDx) although not with the number of hospitalizations. Estimates of annual hospitalization costs were 23.9% lower using HDx and patient utilities did not appear to decline. HDx was statistically significantly associated with reduced hospitalization days and lower medication dosages. Furthermore, this preliminary analysis suggested potential for HDx being a dominant strategy in terms of costs and utility and should motivate future work with larger samples and better controls.

Medium cut-off dialyzers in a large population of hemodialysis patients in Colombia: COREXH registry.

Expanded hemodialysis (HDx) provides increased clearance of conventional and large middle molecules through innovative medium cutoff (MCO) membranes. However, there is a paucity of real-world data regarding the benefits and safety of HDx. This large observational study evaluated outcomes among patients in Colombia undergoing HDx at a extended dialysis clinical services provider. This was a prospective single cohort study of prevalent patients who were treated with HDx; baseline information was collected from the most recent data before patients were started on HDx. Patients were followed prospectively for 1 year for changes in serum albumin and other laboratory parameters compared with the baseline. Survival, hospitalization and safety were assessed from the start of HDx. A total of 1000 patients were invited to enroll; 992 patients met the inclusion criteria for data analysis and 638 patients completed the year of follow-up. Seventy-four (8%) patients died during 866 patient-years (PY) of follow-up; the mortality rate was 8.54 deaths/100 PY (95% confidence interval [CI], 6.8-10.7). There were 673 hospitalization events with a rate of 0.79 events/PY (95% CI, 0.73-0.85) with 6.91 hospital days/PY (95% CI, 6.74-7.09). The observed variability from baseline and maximum average change in mean serum albumin levels were -1.8% and -3.5%, respectively. No adverse events were related to the MCO membrane. HDx using an MCO membrane maintains stable serum albumin levels and is safe in terms of nonoccurrence of dialyzer related adverse events.

Impact of Medium Cut-Off Dialyzers on Patient-Reported Outcomes: COREXH Registry.

INTRODUCTION: A new generation of hemodialysis (HD) membranes called medium cut-off (MCO) membranes possesses enhanced capacities for middle molecule clearance, which have been associated with adverse outcomes in this population. These improvements could potentially positively impact patient-reported outcomes (PROs). OBJECTIVE: The objective of this study was to evaluate the impact of MCO membranes on PROs in a cohort of HD patients in Colombia. METHODS: This was a prospective, multicenter, observational cohort study of 992 patients from 12 renal clinics in Colombia who were switched from high-flux HD to MCO therapy and observed for 12 months. Changes in Kidney Disease Quality of Life 36-Item Short Form Survey (KDQoL-SF36) domains, Dialysis Symptom Index (DSI), and restless legs syndrome (RLS) 12 months after switching to MCO membranes were compared with time on high-flux membranes. Repeated measures of ANOVA were used to evaluate changes in KDQoL-SF36 scores; severity scoring was used to assess DSI changes over time; Cochran's Q test was used to evaluate changes in frequency of diagnostic criteria of RLS. RESULTS: During 12 months of follow-up, 3 of 5 KDQoL-SF36 domains improved compared with baseline: symptoms (p < 0.0001), effects of kidney disease (p < 0.0001), and burden of kidney disease (p < 0.001). The proportion of patients diagnosed with RLS significantly decreased from 22.1% at baseline to 10% at 12 months (p < 0.0001). No significant differences in the number of symptoms (DSI, p = 0.1) were observed, although their severity decreased (p = 0.009). CONCLUSIONS: In conventional HD patients, the expanded clearance of large middle molecules with MCO-HD membranes was associated with higher health-related quality of life scores and a decrease in the prevalence of RLS.