Explaining International Trends in Mortality on Hemodialysis Through Changes in Hemodialysis Practices in the Dialysis Outcomes and Practice Patterns Study (DOPPS).

RATIONALE & OBJECTIVE: Case-mix adjusted hemodialysis mortality has decreased since 1998. Many factors that influence mortality may have contributed to this trend and these associations may differ by continental region. We studied changes in hemodialysis facility practices over time and their potential role in mediating changes in patient survival. STUDY DESIGN: Observational prospective cohort study. SETTING & PARTICIPANTS: Adult hemodialysis patients treated in hemodialysis 500 facilities participating in the Dialysis Outcomes Practice Patterns Study (DOPPS) between 1999 and 2015 in the US, Japan, and 4 four European countries: Germany, Italy, Spain, and UK. PREDICTORS: Four practice measures at each facility: the percentages of patients with Kt/V>1.2, interdialytic weight gain [IDWG]<5.7%, phosphorus<6 mg/dL, and using AV fistulae. OUTCOMES: Patient survival. ANALYTICAL APPROACH: Mediation analyses, adjusted for case mix, were conducted using 3-year study phase as the exposure and facility practice measures as potential mediators. RESULTS: In Europe, we observed a 13% improvement in overall case-mix adjusted survival per decade. Trends in facility practice measures, especially Kt/V and phosphorus, explained 10% improvement in case-mix survival per decade, representing 77% (10% explained of 13% improvement) of the observed improvement. In Japan, 73% of the observed 12%/decade improvement in case-mix adjusted survival could be attributed to facility practices, especially Kt/V and IDWG. In the US, 56% of the observed 47%/decade improvement in case-mix adjusted survival could be attributed to facility practices, especially AV fistula use and phosphorus control. LIMITATIONS: Unmeasured changes in the characteristics of the patient population over this period may confound the observed associations. CONCLUSION: The improvements in adjusted hemodialysis patient survival in Europe, Japan, and the US from 1999 to 2015 can be largely explained by improvements in specific facility practices. Future changes in patient survival may be responsive to further evolution in the implementation of common clinical practices.

Symptom Burden and Its Impact on Quality of Life in Patients With Moderate to Severe CKD: The International Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps).

RATIONALE & OBJECTIVE: Recent evidence suggests substantial burden of symptoms experienced by people with non-dialysis chronic kidney disease (ND-CKD), but informative large-scale studies are scarce. We aimed to assess the prevalence of symptoms, and the association of overall symptom burden with quality of life in patients with moderate to severe CKD. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: 4430 patients with ND-CKD stages 3-5 enrolled into the CKDopps Study in Brazil, France, and the US between 2013 and 2021. EXPOSURES: 13 individual patient-reported symptoms from the KDQOL-SF questionnaire and an overall symptom burden score (low, intermediate, and high). OUTCOMES: Physical and mental component summary scores (PCS, MCS) of the KDQOL-SF. ANALYTICAL APPROACH: Adjusted prevalence ratios and generalized estimating equations. RESULTS: Patients (mean age: 68 years; 40% women; mean baseline eGFR: 30 mL/min/1.73m2) were very much to extremely bothered by numerous symptoms ["soreness in muscles" (23%), "washed out or drained" (21%), "cramps, shortness of breath, dry skin, diminished sex life, or numbness in hands or feet" (14-17%)]. The adjusted prevalences of "cramps", "washed out or drained", "lack of appetite", "nausea/upset stomach", and "sex life" were greater with more severe CKD, and, except for "sex life", in women. A high overall symptom burden was more common in women, in France, and in patients with severe albuminuria and various comorbidities, but not with lower eGFR. PCS and MCS scores were 13.4 and 7.7 points lower, respectively, for high vs. low overall symptom burden. LIMITATIONS: Generalizability limited to patients under nephrology care, residual confounding and inaccurate Brazilian translation of some symptoms. CONCLUSIONS: The high symptom burden observed in this large cohort of ND-CKD patients across three diverse countries and its strong association with poorer HRQOL should inform clinical management of and clinical research in CKD.

Risk factors of peritoneal dialysis-related peritonitis in the Japan Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS).

Background: Peritoneal dialysis (PD)-related peritonitis is a major complication of PD. Wide variations in peritonitis prevention, treatment strategies and consequences are seen between countries. These between-country differences may result from modifiable risk factors and clinical practices. Methods: A total of 1225 Japanese PD patients were included and prospectively followed in the Peritoneal Dialysis Outcomes and Practice Patterns Study phase 1 (2014-2018) and phase 2 (2018-2022). Associations between PD-related peritonitis and various risk factors were assessed by Cox proportional hazards survival models. Results: During follow-up (median 1.52 years), 539 peritonitis episodes were experienced by 364 patients. The country crude peritonitis rate was 0.27 episodes/patient-year. In the fully adjusted model, noticeable patient-level factors associated with experiencing any peritonitis included age {hazard ratio [HR] 1.07 per 5-year increase [95% confidence interval (CI) 1.01-1.14]}, serum albumin level [HR 0.63 per 1 g/dl higher (95% CI 0.48-0.82)] and continuous ambulatory peritoneal dialysis (PD) [HR 1.31 versus automated PD (95% CI 1.05-1.63)]. The adoption of antibiotic prophylaxis practice at the time of PD catheter insertion [HR 0.63 (95% CI 0.51-0.78)] or when having complicated dental procedures [HR 0.74 (95% CI 0.57-0.95)] or lower endoscopy [HR 0.69 (95% CI 0.54-0.89)] were associated with lower hazards of any peritonitis, while a routine facility practice of having more frequent regular medical visits was associated with a higher hazard. Conclusion: Identification of risk factors in Japan may be useful for developing future versions of guidelines and improving clinical practices in Japan. Investigation of country-level risk factors for PD-related peritonitis is useful for developing and implementing local peritonitis prevention and treatment strategies.

Characteristics of patients and facility of peritoneal dialysis in Korea: Results from the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) Korea.

BACKGROUND: Varying peritoneal dialysis (PD)-related clinical outcomes have been reported in different countries. As a participant of the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS), this study investigated the characteristics of Korean PD patients, PD facilities and the incidence rates of clinical outcomes including mortality and PD-related outcomes. METHODS: From July 2019 to December 2021, a total of 766 Korean PD patients were included for analysis. Poisson regression analysis was used to explore the incidence rates of various clinical events including mortality, modality transfer, exit site or catheter tunnel infection and peritonitis. RESULTS: Among the 766 patients (median age 55.5 years, males 59.5%), 276 were incident and 490 were prevalent PD patients. The incidence rates of events were as follows: all-cause mortality (0.048), modality transfer (0.051), exit site or catheter tunnel infection (0.054) and peritonitis (0.136) events per person year. The most common causative organism for exit site or tunnel infection was staphylococcus species (47%) and that for peritonitis was streptococcus (28%) followed by staphylococcus (27%) species. CONCLUSIONS: Up to now, PDOPPS Korea has recruited 766 Korean PD patients and started documentation of major PD-related outcomes which occurred during the follow-up period. The overall incidence rates of clinical outcomes in Korean PD patients were relatively favourable. There was no statistically significant difference in the incidence rates of clinical outcomes according to both facility and patient factors.

International variations in serum PTH and calcium levels and their mortality associations in peritoneal dialysis patients: Results from PDOPPS.

BACKGROUND: Mineral bone disorder (MBD) in chronic kidney disease (CKD) is associated with high symptom burden, fractures, vascular calcification, cardiovascular disease and increased morbidity and mortality. CKD-MBD studies have been limited in peritoneal dialysis (PD) patients. Here, we describe calcium and parathyroid hormone (PTH) control, related treatments and mortality associations in PD patients. METHODS: We used data from eight countries (Australia and New Zealand (A/NZ), Canada, Japan, Thailand, South Korea, United Kingdom, United States (US)) participating in the prospective cohort Peritoneal Dialysis Outcomes and Practice Patterns Study (2014-2022) among patients receiving PD for >3 months. We analysed the association of baseline PTH and albumin-adjusted calcium (calciumAlb) with all-cause mortality using Cox regression, adjusted for potential confounders, including serum phosphorus and alkaline phosphatase. RESULTS: Mean age ranged from 54.6 years in South Korea to 63.5 years in Japan. PTH and serum calciumAlb were measured at baseline in 12,642 and 14,244 patients, respectively. Median PTH ranged from 161 (Japan) to 363 pg/mL (US); mean calciumAlb ranged from 9.1 (South Korea, US) to 9.8 mg/dL (A/NZ). The PTH/mortality relationship was U-shaped, with the lowest risk at PTH 300-599 pg/mL. Mortality was nearly 20% higher at serum calciumAlb 9.6+ mg/dL versus 8.4-<9.6 mg/dL. MBD therapy prescriptions varied substantially across countries. CONCLUSIONS: A large proportion of PD patients in this multi-national study have calcium and/or PTH levels in ranges associated with substantially higher mortality. These observations point to the need to substantially improve MBD management in PD to optimise patient outcomes. LAY SUMMARY: Chronic kidney disease-mineral bone disorder (MBD) is a systemic condition, common in dialysis patients, that results in abnormalities in parathyroid hormone (PTH), calcium, phosphorus and vitamin D metabolism. A large proportion of peritoneal dialysis (PD) patients in this current multi-national study had calcium and/or PTH levels in ranges associated with substantially higher risks of death. Our observational study design limits our ability to determine whether these abnormal calcium and PTH levels cause more death due to possible confounding that was not accounted for in our analysis. However, our findings, along with other recent work showing 48-75% higher risk of death for the one-third of PD patients having high phosphorus levels (>5.5 mg/dL), should raise strong concerns for a greater focus on improving MBD management in PD patients.

CKD-Associated Pruritus and Clinical Outcomes in Nondialysis CKD.

Rationale & Objective: Itching is a frequent symptom experienced by people with chronic kidney disease (CKD). We investigated the associations of CKD-associated pruritus (CKD-aP) with clinical outcomes. Study Design: This was a longitudinal cohort study. Setting & Participants: Patients from Brazil, France, and the United States enrolled in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) from 2013 to 2021, an international prospective cohort study of adults with nondialysis dependent CKD, and an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2 were included. Exposure: CKD-aP was self-reported by response to the question: "During the past 4 weeks, to what extent were you bothered by itchy skin?" Outcomes: The outcomes were as follows: CKD progression, kidney replacement therapy (KRT) initiation, mortality, hospitalization, cardiovascular events, infection events. Analytical Approach: Associations with time-to-event outcomes were investigated using Cox proportional hazards models adjusted for potential confounders. Results: There were 4,410 patients from 91 clinics with a median age of 69 years and a median eGFR at patient questionnaire completion of 29 (21-38) mL/min/1.73 m2. The proportion of patients not at all, somewhat, moderately, very much, and extremely bothered by itchy skin was 49%, 27%, 13%, 7%, and 3%, respectively. Patients with more advanced stages of CKD, older age, and greater comorbidities reported to be more likely bothered by itchy skin. Among patients at least moderately bothered, 23% were prescribed at least 1 pharmacotherapy (35% in the United States, 19% in France, 4% in Brazil), including antihistamine (10%), gabapentin (6%), topical corticosteroids (4%), pregabalin (3%), or sedating antihistamine (3%). The HR (95% CI) for patients extremely (vs not at all) bothered was 1.74 (1.11-2.73) for all-cause mortality, 1.56 (1.11-2.18) for all-cause hospitalization, and 1.84 (1.22-2.75) for cardiovascular events. As CKD-aP severity increased, patients also had higher rates of infection events (P = 0.04); CKD-aP severity was not associated with KRT initiation (P = 0.20) or CKD progression (P = 0.87). Limitations: The limitations were 25% nonresponse rate, recall bias, and residual confounding factors. Conclusions: These results demonstrate a strong association between severe itch and clinical outcomes, providing the nephrology community new insights into the possible adverse consequences of CKD-aP in individuals with nondialysis CKD, and warrant further exploration. Plain-Language Summary: Chronic kidney disease-associated pruritus (CKD-aP) is a common disturbing symptom of chronic kidney disease (CKD). This article analyzes longitudinal data from the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) to describe prevalence of CKD-aP in 4,410 individuals with nondialysis CKD, and its association with clinical outcomes. We found that 51% of the surveyed population were bothered by pruritus. CKD-aP was more prevalent in those with more advanced stages of CKD, older age, and with more comorbid conditions. Compared to those not at all bothered by pruritus, those who were extremely bothered had a higher risk of all-cause mortality, hospitalizations, and cardiovascular events. Severity of CKD-aP was not associated with CKD progression or initiation of kidney replacement therapy.

The chronic kidney disease outcomes and practice patterns study Brazil (CKDopps-Brazil): Design, data and methodology / Estudo dos desfechos de doenca renal cronica e padroes da pratica atual - Brasil (CKDopps-Brazil): Desenho, dados e metodologia

Introduction: The chronic kidney disease outcomes and practice patterns study (CKDopps) is an international observational, prospective, cohort study involving patients with chronic kidney disease (CKD) stages 3-5 [estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2, with a major focus upon care during the advanced CKD period (eGFR < 30 ml/min/1.73 m2)]. During a 1-year enrollment period, each one of the 22 selected clinics will enroll up to 60 advanced CKD patients (eGFR < 30 ml/min/1.73 m2 and not dialysis-dependent) and 20 earlier stage CKD patients (eGFR between 30-59 ml/min/1.73 m2). Exclusion criteria: age < 18 years old, patients on chronic dialysis or prior kidney transplant. The study timeline include up to one year for enrollment of patients at each clinic starting in the end of 2013, followed by up to 2-3 years of patient follow-up with collection of detailed longitudinal patient-level data, annual clinic practice-level surveys, and patient surveys. Analyses will apply regression models to evaluate the contribution of patient-level and clinic practice-level factors to study outcomes, and utilize instrumental variable-type techniques when appropriate. Conclusion: Launching in 2013, CKDopps Brazil will study advanced CKD care in a random selection of nephrology clinics across Brazil to gain understanding of variation in care across the country, and as part of a multinational study to identify optimal treatment practices to slow kidney disease progression and improve outcomes during the transition period to end-stage kidney disease. .

Introdução: O Estudo de padrões da prática e desfechos das doenças renais crônicas (CKDopps) é um estudo internacional observacional, prospectivo, com uma coorte composta de pacientes com doenças renais crônicas (DRC) nos estágios 3-5 [taxa de filtração glomerular estimada (eGFR) < 60 ml/min/1,73 m2, com um grande foco sobre o tratamento durante o período de doença renal crônica avançada (eGFR < 30 ml/min/1,73 m2)]. Durante o período de recrutamento de participantes, de 1 ano, cada uma das 22 clínicas selecionadas inscreverá até 60 pacientes com DRC avançada (eGFR < 30 ml/min/1,73 m2 e não dependente de diálise) e 20 pacientes com DRC em estágios anteriores (eGFR entre 30-59 ml/min/1,73 m2). Os critérios de exclusão são: idade < 18 anos; pacientes em diálise crônica ou transplante de rim prévio. O cronograma de estudo inclui até um ano para a inscrição dos pacientes em cada clínica a partir do final de 2013, sendo então acompanhados por 2-3 anos, com coleta de dados longitudinais detalhados dos pacientes, pesquisas anuais dos níveis da prática na clínica e levantamentos de informação dos pacientes. As análises aplicarão modelos de regressão para avaliar a contribuição de fatores relacionados à clínica e aos próprios pacientes para estudar os desfechos, e utilizar técnicas do tipo: variável instrumental, quando apropriado. Conclusão: Lançado em 2013, o CKDopps-Brasil, avaliará o tratamento de DRC avançada em uma seleção aleatória de clínicas de nefrologia em todo o Brasil para entender como o tratamento varia em nosso país, e como parte de um estudo multinacional para identificar as práticas de tratamento ideal para retardar ...