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Background Severely ill people with coronavirus disease 2019 (COVID-19) are at risk of acute kidney injury treated with renal replacement therapy (AKI-RRT). The understanding of the risk factors and outcomes for AKI-RRT is incomplete. Methods We prospectively collected data on the incidence, demographics, area of residence, time course, outcomes and associated risk factors for all COVID-19 AKI-RRT cases during the first two waves of the pandemic in Ontario, Canada. Results There were 271 people with AKI-RRT, representing 0.1% of all diagnosed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases. These included 10% of SARS-CoV-2 admissions to intensive care units (ICU). Median age was 65 years, with 11% <50 years, 76% were male, 47% non-White and 48% had diabetes. Overall, 59% resided in the quintile of Ontario neighborhoods with the greatest ethnocultural composition and 51% in the two lowest income quintile neighborhoods. Mortality was 58% at 30 days after RRT initiation, and 64% at 90 days. By 90 days, 20% of survivors remained RRT-dependent and 31% were still hospitalized. On multivariable analysis, people aged >70 years had higher mortality (odds ratio 2.4, 95% confidence interval 1.3, 4.6). Cases from the second versus the first COVID-19 wave were older, had more baseline comorbidity and were more likely to initiate RRT  >2 weeks after SARS-CoV-2 diagnosis (34% versus 14%; P < 0.001). Conclusions AKI-RRT is common in COVID-19 ICU admissions. Residency in areas with high ethnocultural composition and lower socioeconomic status are strong risk factors. Late-onset AKI-RRT was more common in the second wave. Mortality is high and 90-day survivors have persisting high morbidity. [ABSTRACT FROM AUTHOR]

BACKGROUND: Patients undergoing long-term dialysis may be at higher risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and of associated disease and mortality. We aimed to describe the incidence, risk factors and outcomes for infection in these patients in Ontario, Canada. METHODS: We used linked data sets to compare disease characteristics and mortality between patients receiving long-term dialysis in Ontario who were diagnosed SARS-CoV-2 positive and those who did not acquire SARS-CoV-2 infection, between Mar. 12 and Aug. 20, 2020. We collected data on SARS-CoV-2 infection prospectively. We evaluated risk factors for infection and death using multivariable logistic regression analyses. RESULTS: During the study period, 187 (1.5%) of 12 501 patients undergoing dialysis were diagnosed with SARS-CoV-2 infection. Of those with SARS-CoV-2 infection, 117 (62.6%) were admitted to hospital and the case fatality rate was 28.3%. Significant predictors of infection included in-centre hemodialysis versus home dialysis (odds ratio [OR] 2.54, 95% confidence interval [CI] 1.59–4.05), living in a long-term care residence (OR 7.67, 95% CI 5.30–11.11), living in the Greater Toronto Area (OR 3.27, 95% CI 2.21–4.80), Black ethnicity (OR 3.05, 95% CI 1.95–4.77), Indian subcontinent ethnicity (OR 1.70, 95% CI 1.02–2.81), other non-White ethnicities (OR 2.03, 95% CI 1.38–2.97) and lower income quintiles (OR 1.82, 95% CI 1.15–2.89). INTERPRETATION: Patients undergoing long-term dialysis are at increased risk of SARS-CoV-2 infection and death from coronavirus disease 2019. Special attention should be paid to addressing risk factors for infection, and these patients should be prioritized for vaccination. [ABSTRACT FROM AUTHOR]

Background. Beta-blockers may be cardioprotective in patients receiving chronic dialysis. We examined cardiovascular outcomes among incident dialysis patients receiving beta-blocker therapy.Methods. We conducted a retrospective cohort study employing linked healthcare databases in Ontario, Canada. We studied all consecutive chronic dialysis patients aged ≥66 years who initiated dialysis between 1 July 1991 and 31 July 2007. Patients were divided into three groups according to new medication use after the initiation of chronic dialysis. The three groups were patients initiated on beta-blockers, calcium channel blockers and statins only. Patients in the beta-blocker and calcium channel blocker groups could also be concurrently receiving a statin. The primary outcome was time to a composite endpoint of death, myocardial infarction, stroke or coronary revascularization.Results. There were a total of 1836 patients (504 beta-blocker, 570 calcium channel blocker and 762 statin-only users). Compared to statin-only use, beta-blocker use was not associated with improved cardiovascular outcomes [adjusted hazard ratio (aHR) 1.07, 95% confidence interval (CI) 0.92–1.23]. As expected, calcium channel blocker use was also not associated with improved cardiovascular outcomes (aHR 0.91, 95% CI 0.79–1.06). Among all subgroup analyses by beta-blocker attributes, only high-dose beta-blocker therapy was associated with better cardiovascular outcomes as compared to low-dose beta-blockers (aHR 0.50, 95% CI 0.29–0.88).Conclusions. We observed no beneficial effect of beta-blocker use among patients receiving chronic dialysis relative to our comparator groups. Given current uncertainty around the cardioprotective benefits of beta-blockers in patients receiving dialysis, a large randomized clinical trial is warranted. [ABSTRACT FROM PUBLISHER]

Background: Coronavirus disease 2019 (COVID-19) vaccine effectiveness studies in the hemodialysis population have demonstrated that two doses of mRNA COVID-19 vaccines are effective against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe complications when Alpha and Delta were predominant variants of concern. Vaccine effectiveness after a third dose versus two doses for preventing SARS-CoV-2 infection and severe COVID-19 in the hemodialysis population against Omicron is not known., Methods: We conducted a retrospective cohort study in Ontario, Canada, between December 1, 2021, and February 28, 2022, in the maintenance hemodialysis population who had received two versus three doses of mRNA COVID-19 vaccines. COVID-19 vaccination, SARS-CoV-2 infection, and related hospitalization and death were determined from provincial databases. The primary outcome was the first RT-PCR confirmed SARS-CoV-2 infection, and the secondary outcome was a SARS-CoV-2-related severe outcome, defined as either hospitalization or death., Results: A total of 8457 individuals receiving in-center hemodialysis were included. At study initiation, 2334 (28%) individuals received three doses, which increased to 7468 (88%) individuals by the end of the study period. The adjusted hazard ratios (aHR) for SARS-CoV-2 infection (aHR, 0.58; 95% confidence interval [CI], 0.50 to 0.67) and severe outcomes (hospitalization or death) (aHR, 0.40; 95% CI, 0.28 to 0.56) were lower after three versus two doses of mRNA vaccine. Prior infection, independent of vaccine status, was associated with a lower risk of reinfection, with an aHR of 0.44 (95% CI, 0.27 to 0.73)., Conclusions: Three-dose mRNA COVID-19 vaccination was associated with lower incidence of SARS-CoV-2 infection and severe SARS-CoV-2-related outcomes during the Omicron period compared with two doses., (Copyright © 2023 by the American Society of Nephrology.)

Background: People with advanced CKD are at high risk of mortality and morbidity from coronavirus disease 2019 (COVID-19). We measured rates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe outcomes in a large population attending advanced CKD clinics during the first 21 months of the pandemic. We examined risk factors for infection and case fatality, and we assessed vaccine effectiveness in this population., Methods: In this retrospective cohort study, we analyzed data on demographics, diagnosed SARS-CoV-2 infection rates, outcomes, and associated risk factors, including vaccine effectiveness, for people attending a province-wide network of advanced CKD clinics during the first four waves of the pandemic in Ontario, Canada., Results: In a population of 20,235 patients with advanced CKD, 607 were diagnosed with SARS-CoV-2 infection over 21 months. The case fatality rate at 30 days was 19% overall but declined from 29% in the first wave to 14% in the fourth. Hospitalization and intensive care unit (ICU) admission rates were 41% and 12%, respectively, and 4% started long-term dialysis within 90 days. Significant risk factors for diagnosed infection on multivariable analysis included lower eGFR, higher Charlson Comorbidity Index, attending advanced CKD clinics for more than 2 years, non-White ethnicity, lower income, living in the Greater Toronto Area, and long-term care home residency. Being doubly vaccinated was associated with lower 30-day case fatality rate (odds ratio [OR], 0.11; 95% confidence interval [CI], 0.03 to 0.52). Older age (OR, 1.06 per year; 95% CI, 1.04 to 1.08) and higher Charlson Comorbidity Index (OR, 1.11 per unit; 95% CI, 1.01 to 1.23) were associated with higher 30-day case fatality rate., Conclusions: People attending advanced CKD clinics and diagnosed with SARS-CoV-2 infection in the first 21 months of the pandemic had high case fatality and hospitalization rates. Fatality rates were significantly lower in those who were doubly vaccinated., Podcast: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023&#95;04&#95;10&#95;CJN10560922.mp3., (Copyright © 2023 by the American Society of Nephrology.)

Background: Vaccination studies in the hemodialysis population have demonstrated decreased antibody response compared with healthy controls, but vaccine effectiveness for preventing SARS-CoV-2 infection and severe disease is undetermined., Methods: We conducted a retrospective cohort study in the province of Ontario, Canada, between December 21, 2020, and June 30, 2021. Receipt of vaccine, SARS-CoV-2 infection, and related severe outcomes (hospitalization or death) were determined from provincial health administrative data. Receipt of one and two doses of vaccine were modeled in a time-varying cause-specific Cox proportional hazards model, adjusting for baseline characteristics, background community infection rates, and censoring for non-COVID death, recovered kidney function, transfer out of province, solid organ transplant, and withdrawal from dialysis., Results: Among 13,759 individuals receiving maintenance dialysis, 2403 (17%) were unvaccinated and 11,356 (83%) had received at least one dose by June 30, 2021. Vaccine types were BNT162b2 ( n =8455, 74%) and mRNA-1273 ( n =2901, 26%); median time between the first and second dose was 36 days (IQR 28-51). The adjusted hazard ratio (HR) for SARS-CoV-2 infection and severe outcomes for one dose compared with unvaccinated was 0.59 (95% CI, 0.46 to 0.76) and 0.54 (95% CI, 0.37 to 0.77), respectively, and for two doses compared with unvaccinated was 0.31 (95% CI, 0.22 to 0.42) and 0.17 (95% CI, 0.1 to 0.3), respectively. There were no significant differences in vaccine effectiveness among age groups, dialysis modality, or vaccine type., Conclusions: COVID-19 vaccination is effective in the dialysis population to prevent SARS-CoV-2 infection and severe outcomes, despite concerns about suboptimal antibody responses., (Copyright © 2022 by the American Society of Nephrology.)

Background: Differences in immunogenicity between mRNA SARS-CoV-2 vaccines have not been well characterized in patients undergoing dialysis. We compared the serologic response in patients undergoing maintenance hemodialysis after vaccination against SARS-CoV-2 with BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)., Methods: We conducted a prospective observational cohort study at 2 academic centres in Toronto, Canada, from Feb. 2, 2021, to July 20, 2021, which included 129 and 95 patients who received the BNT162b2 and mRNA-1273 SARS-CoV-2 vaccines, respectively. We measured SARS-CoV-2 immunoglobulin G antibodies to the spike protein (anti-spike), receptor binding domain (anti-RBD) and nucleocapsid protein (anti-NP) at 6-7 and 12 weeks after the second dose of vaccine and compared those levels with the median convalescent serum antibody levels from 211 controls who were previously infected with SARS-CoV-2., Results: At 6-7 weeks after 2-dose vaccination, we found that 51 of 70 patients (73%) who received BNT162b2 and 83 of 87 (95%) who received mRNA-1273 attained convalescent levels of anti-spike antibody ( p < 0.001). In those who received BNT162b2, 35 of 70 (50%) reached the convalescent level for anti-RBD compared with 69 of 87 (79%) who received mRNA-1273 ( p < 0.001). At 12 weeks after the second dose, anti-spike and anti-RBD levels were significantly lower in patients who received BNT162b2 than in those who received mRNA-1273. For anti-spike, 70 of 122 patients (57.4%) who received BNT162b2 maintained the convalescent level versus 68 of 71 (96%) of those who received mRNA-1273 ( p < 0.001). For anti-RBD, 47 of 122 patients (38.5%) who received BNT162b2 maintained the anti-RBD convalescent level versus 45 of 71 (63%) of those who received mRNA-1273 ( p = 0.002)., Interpretation: In patients undergoing hemodialysis, mRNA-1273 elicited a stronger humoral response than BNT162b2. Given the rapid decline in immunogenicity at 12 weeks in patients who received BNT162b2, a third dose is recommended in patients undergoing dialysis as a primary series, similar to recommendations for other vulnerable populations., Competing Interests: Competing interests: Mohammad Atiquzzaman and Adeera Levein are employees of the BC Renal Agency. Matthew Oliver and Michelle Hladunewich are contracted medical leads at Ontario Renal Network, Ontario Health. Matthew Oliver is the owner of Oliver Medical Management Inc., which licenses Dialysis Management Analysis and Reporting (DMAR) System software. He holds a Canadian patent for DMAR System, has received speaker fees from Baxter Healthcare and participated on advisory boards for Janssen and Amgen. Jeffrey Perl has received consultant fees from Baxter Healthcare, US Renal Care, Davita Healthcare Partners, Otsuka Canada and AstraZeneca Canada, outside the submitted work; grants from the Agency for Healthcare Research and Quality grant support; and speaker fees from Baxter Healthcare, Fresenius Medical Care USA, AstraZeneca, Davita Healthcare Partners and US Renal Care. Shelly Bolotin has received funding from the Canadian Institutes of Health Research (CIHR), the Canadian Immunization Research Network, the COVID-19 Immunity Task Force and the Public Health Agency of Canada, outside the submitted work. She is a member of the Canadian Immunization Research Network Management Committee and the COVID-19 Immunity Task Force Leadership Group. Vanessa Tran reports that Public Health Ontario received funding from the Public Health Agency of Canada and test kits from the Canadian Immunity Task Force for COVID-19 serosurveillance studies. Public Health Ontario is also involved in a COVID-19 mix-and-match vaccine clinical trial. Shelly Bolotin and Vanessa Tran are employees of Public Health Ontario. Adeera Levin is the Lead Integrated Clinical and Academic Networks for Providence Health Care. She has participated on the boards of the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health and Australian Kidney Clinical Trials Network. She has a leadership or fiduciary role for the International Society of Nephrology (ISN) Advocacy Group, ISN International CKDu Consortium, ISN Research Committee, and the BC Renal Agency. She has received honoraria from GSK, Takeda, Reata, Astra Zeneca and Janssen; and payment for expert testimony from Osler. Peter Blake is the medical director at the Ontario Renal Network, Ontario Health, and has received speaker fees from Baxter Global. Anne-Claude Gingras is a member of the working parties (testing and immunology) of the COVID-19 Immunity Task Force, is the chair of the CIHR Institute of Genetics Institute Advisory Board is a member of the National Research Council of Canada Human Health Therapeutics Board and is the Pillar lead, Functional Genomics and Structure-Function at CoVaRR-Net. Michelle Hladunewich has received grants from Pfizer, Ionis, Chemocentryx, Calliditas and Roche; consultant fees from Alynylam; and royalties from UpToDate, outside the submitted work. Jerome Leis has received payments for expert testimony from the Ontario Hospital Association and the Ministry of the Attorney General of Ontario and has a leadership role with Choosing Wisely Canada. Kevin Yau has received speaker fees from AstraZeneca. No other competing interests were declared., (© 2022 CMA Impact Inc. or its licensors.)

Background: Patients undergoing long-term dialysis may be at higher risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and of associated disease and mortality. We aimed to describe the incidence, risk factors and outcomes for infection in these patients in Ontario, Canada., Methods: We used linked data sets to compare disease characteristics and mortality between patients receiving long-term dialysis in Ontario who were diagnosed SARS-CoV-2 positive and those who did not acquire SARS-CoV-2 infection, between Mar. 12 and Aug. 20, 2020. We collected data on SARS-CoV-2 infection prospectively. We evaluated risk factors for infection and death using multivariable logistic regression analyses., Results: During the study period, 187 (1.5%) of 12 501 patients undergoing dialysis were diagnosed with SARS-CoV-2 infection. Of those with SARS-CoV-2 infection, 117 (62.6%) were admitted to hospital and the case fatality rate was 28.3%. Significant predictors of infection included in-centre hemodialysis versus home dialysis (odds ratio [OR] 2.54, 95% confidence interval [CI] 1.59-4.05), living in a long-term care residence (OR 7.67, 95% CI 5.30-11.11), living in the Greater Toronto Area (OR 3.27, 95% CI 2.21-4.80), Black ethnicity (OR 3.05, 95% CI 1.95-4.77), Indian subcontinent ethnicity (OR 1.70, 95% CI 1.02-2.81), other non-White ethnicities (OR 2.03, 95% CI 1.38-2.97) and lower income quintiles (OR 1.82, 95% CI 1.15-2.89)., Interpretation: Patients undergoing long-term dialysis are at increased risk of SARS-CoV-2 infection and death from coronavirus disease 2019. Special attention should be paid to addressing risk factors for infection, and these patients should be prioritized for vaccination., Competing Interests: Competing interests: Leena Taji, Doneal Thomas, Jane Ip, Yiwen Tang, Angie Yeung and Rebecca Cooper are salaried employees of Ontario Renal Network, Ontario Health. Matthew Oliver, Phil McFarlane and Peter Blake are contracted Medical Leads at Ontario Renal Network, Ontario Health. Matthew Oliver is owner of Oliver Medical Management Inc., which licenses Dialysis Management Analysis and Reporting System software. He has received honoraria for speaking from Baxter Healthcare and participated on Advisory Boards for Janssen and Amgen. Peter Blake has received honoraria from Baxter Global for speaking engagements. Andrew House has received honoraria from Baxter for speaking engagements. Phil McFarlane has received consultant or lecture fees from Amgen, Astra-Zeneca, Bayer, BMS, Boehringer-Ingelheim, GSK, Janssen, Lilly, Novartis, Otsuka, Sanofi-Aventis, Servier and Vifor. He has also received research grants from Amgen, Astra-Zeneca, Bayer, Boehringer-Ingelheim and Otsuka. No other competing interests were declared., (© 2021 Joule Inc. or its licensors.)

Background:: We assessed the validity of physician billing codes and hospital admission using International Classification of Diseases 10th revision codes to identify vascular access placement, secondary patency, and surgical revisions in administrative data., Methods:: We included adults (≥18 years) with a vascular access placed between 1 April 2004 and 31 March 2013 at the University Health Network, Toronto. Our reference standard was a prospective vascular access database (VASPRO) that contains information on vascular access type and dates of placement, dates for failure, and any revisions. We used VASPRO to assess the validity of different administrative coding algorithms by calculating the sensitivity, specificity, and positive predictive values of vascular access events., Results:: The sensitivity (95% confidence interval) of the best performing algorithm to identify arteriovenous access placement was 86% (83%, 89%) and specificity was 92% (89%, 93%). The corresponding numbers to identify catheter insertion were 84% (82%, 86%) and 84% (80%, 87%), respectively. The sensitivity of the best performing coding algorithm to identify arteriovenous access surgical revisions was 81% (67%, 90%) and specificity was 89% (87%, 90%). The algorithm capturing arteriovenous access placement and catheter insertion had a positive predictive value greater than 90% and arteriovenous access surgical revisions had a positive predictive value of 20%. The duration of arteriovenous access secondary patency was on average 578 (553, 603) days in VASPRO and 555 (530, 580) days in administrative databases., Conclusion:: Administrative data algorithms have fair to good operating characteristics to identify vascular access placement and arteriovenous access secondary patency. Low positive predictive values for surgical revisions algorithm suggest that administrative data should only be used to rule out the occurrence of an event.

Some β-blockers are efficiently removed from the circulation by hemodialysis ("high dialyzability") whereas others are not ("low dialyzability"). This characteristic may influence the effectiveness of the β-blockers among patients receiving long-term hemodialysis. To determine whether new use of a high-dialyzability β-blocker compared with a low-dialyzability β-blocker associates with a higher rate of mortality in patients older than age 66 years receiving long-term hemodialysis, we conducted a propensity-matched population-based retrospective cohort study using the linked healthcare databases of Ontario, Canada. The high-dialyzability group (n=3294) included patients initiating atenolol, acebutolol, or metoprolol. The low-dialyzability group (n=3294) included patients initiating bisoprolol or propranolol. Initiation of a high- versus low-dialyzability β-blocker was associated with a higher risk of death in the following 180 days (relative risk, 1.4; 95% confidence interval, 1.1 to 1.8; P<0.01). Supporting this finding, we repeated the primary analysis in a cohort of patients not receiving hemodialysis and found no significant association between dialyzability and the risk of death (relative risk, 1.0; 95% confidence interval, 0.9 to 1.3; P=0.71). β-Blocker exposure was not randomly allocated in this study, so a causal relationship between dialyzability and mortality cannot be determined. However, our findings should raise awareness of this potentially important drug characteristic and prompt further study., (Copyright © 2015 by the American Society of Nephrology.)

Adequacy of chronic kidney disease (CKD) care is traditionally measured as early or late, but this does not reflect the effect of cumulative or consistent care. Here we relate alternate measures of CKD care to mortality and other outcomes in patients with end-stage renal disease (ESRD) who started renal replacement therapy (RRT) between 1998 and 2008. CKD care was defined traditionally as early or late, and alternatively as cumulative care (total visits) and consistency of care in the critical period immediately prior to start of RRT (consistent critical period care required visits in 3 or more of the 6 months prior to RRT start). The primary outcome was 1-year mortality, with secondary outcomes of inpatient start and access creation. Of 12,143 patients aged 18-97 years at the start of RRT, 75.9% had early CKD care. Only 38.3% of the early group had high cumulative (over 10 visits) and consistent critical period care. The 1-year mortality of 15.8% was more likely with late care, lower cumulative care, and inconsistent critical period care. Both cumulative care and consistent critical period care independently predicted mortality, as well as secondary outcomes. Alternate measures of CKD care are important predictors of outcomes in ESRD and should be considered when reporting adequacy of care. Thus, patients traditionally classified as receiving early CKD care often do not receive adequate care immediately prior to initiating RRT.

Background and Objectives: Guidelines promote early fistula creation to avoid central venous catheter use. This practice may lead to fistula creations in patients who never receive dialysis. The objective of this study was to estimate the risk of fistula nonuse with long-term follow-up., Design, Setting, Participants, & Measurements: Administrative health data identified 1929 predialysis adults who had their first fistula creation between April of 2002 and March of 2006. Patients were followed for a minimum of 2 years or until they began dialysis, received a kidney transplant, or died., Results: The median follow-up times in patients who started dialysis, died without receiving dialysis, and remained in predialysis were 6.1, 11.5, and 38.7 months, respectively. Eighty-one percent of patients initiated dialysis; 9% of patients died without receiving dialysis, and 10% of patients remained predialysis. Forty percent of patients had their first fistula creation 3-12 months before initiating dialysis (the recommended window). Thirty percent were created within 90 days of starting dialysis; 30% were created more than 1 year before starting dialysis, and 10% were created more than 2 years before starting dialysis. Older patients, females, and patients with less comorbidity were not as likely to initiate dialysis after incident fistula creation., Conclusions: Most patients who underwent fistula creation before starting dialysis eventually received dialysis with extended follow-up, but the risk was significantly modified by age, sex, and comorbidity. Many patients had fistula creations earlier or later than recommended.

Background: Patients choosing between hemodialysis (HD) and peritoneal dialysis (PD) should be well informed of the risks and benefits of each modality. Invasive access interventions are important outcomes because frequent interventions lower patient's quality of life and consume limited resources. The objective of this study was to compare the risk of access interventions between the two modalities., Methods: Three hundred and sixty-nine incident chronic dialysis patients were prospectively enrolled at four Canadian centers that were eligible for both modalities, received at least 4 months of pre-dialysis care and started dialysis electively as an outpatient. Two hundred and twenty-four (61%) chose PD and 145 (39%) chose HD. Patients were followed for an average of 1.3 years (range 0.07-3.6 years)., Results: In the PD group, there were fewer access interventions (2.5 versus 3.1 interventions per patient, adjusted odds ratio of 0.79 for PD versus HD, P = 0.005) and a lower intervention rate (2.3 versus 1.9 per patient-year, adjusted rate ratio of 0.81 for PD versus HD, P = 0.04). PD catheters were less likely to experience primary failure (4.6 versus 32%, P < 0.0001), showed a trend toward lower intervention rates during use (0.8 versus 1.2 per patient-year, P = 0.06), and had equal patency compared to fistulae (1-year patency of 84 versus 88%, P = 0.48). Patients managed exclusively with HD catheters (28% of the HD group) required 1.7 interventions per patient and an intervention rate of 1.9 per patient-year., Conclusion: Patients who choose PD require fewer access interventions to maintain dialysis access than patients choosing HD.

The relative risk of death for patients treated with peritoneal dialysis compared with those treated with hemodialysis appears to change with duration of dialysis therapy. Patients who start dialysis urgently are at high risk for mortality and are treated almost exclusively with hemodialysis, introducing bias to such mortality comparisons. To better isolate the association between dialysis treatment modality and patient mortality, we examined the relative risk for mortality for peritoneal dialysis compared with hemodialysis among individuals who received ≥4 months of predialysis care and who started dialysis electively as outpatients. From a total of 32,285 individuals who received dialysis in Ontario, Canada during a nearly 8-year period, 6,573 patients met criteria for elective, outpatient initiation. We detected no difference in survival between peritoneal dialysis and hemodialysis after adjusting for relevant baseline characteristics. The relative risk of death did not change with duration of dialysis therapy in our primary analysis, but it did change with time when we defined our patient population using the more inclusive criteria typical of previous studies. These results suggest that peritoneal dialysis and hemodialysis associate with similar survival among incident dialysis patients who initiate dialysis electively, as outpatients, after at least 4 months of predialysis care. Selection bias, rather than an effect of the treatment itself, likely explains the previously described change in the relative risk of death over time between hemodialysis and peritoneal dialysis.

Background: Administrative databases are increasingly being used to study the incident dialysis population and have important advantages. However, traditional methods of risk adjustment have limitations in this patient population., Objective: Our objective was to develop a prognostic index for 1-year mortality in incident dialysis patients using administrative data that was applicable to ambulatory patients, used objective definitions of candidate predictor variables, and was easily replicated in other environments., Research Design: Anonymized, administrative health data housed at the Institute for Clinical Evaluative Sciences in Toronto, Canada were used to identify a population-based sample of 16,205 patients who initiated dialysis between July 1, 1998 and March 31, 2005. The cohort was divided into derivation, validation, and testing samples and 4 different strategies were used to derive candidate logistic regression models for 1-year mortality. The final risk prediction model was selected based on discriminatory ability (as measured by the c-statistic) and a risk prediction score was derived using methods adopted from the Framingham Heart Study. Calibration of the predictive model was assessed graphically., Results: The risk of death during the first year of dialysis therapy was 16.4% in the derivation sample. The final model had a c-statistic of 0.765, 0.763, and 0.756 in the derivation, validation, and testing samples, respectively. Plots of actual versus predicted risk of death at 1-year showed good calibration., Conclusion: The prognostic index and summary risk score accurately predict 1-year mortality in incident dialysis patients and can be used for the purposes of risk adjustment.

Background: The use of administrative health data and other secondary data sources to conduct research are increasing, and the quality of these data requires careful scrutiny to ensure that findings of studies based on them are accurate., Methods: We conducted a multicenter, chart-abstraction study in Ontario, Canada to evaluate the ability of linked administrative databases to identify important baseline demographic and treatment information, changes in dialysis treatment modality over time, and the occurrence of important outcome events in incident dialysis patients. The medical record was considered the reference standard., Results: Within administrative databases, demographic information was very well coded, as was the location where individuals started dialysis, the first treatment modality, the first outpatient modality, and the treatment that was in use 90 days after the start of therapy. The ability to accurately recreate an individual patient's entire dialysis treatment history using physician billing claims was somewhat limited. The treatment changes were often identified in the correct temporal sequence, but the dates that the events occurred did not agree well. Finally, important outcomes including the death and kidney transplantation were captured well, although the recovery of kidney function could not be evaluated because of poor inter-rater reliability., Conclusions: This validation study provides important information concerning the ability to detect variables related to dialysis care using administrative datasets. Validation work should focus not only on the ability of secondary data to identify baseline comorbidities, but should also attempt to verify that other key variables required to conduct analyses are reliably captured.

Background: To provide better dialysis care to rural communities, the Ministry of Health chose to build satellite haemodialysis (HD) units, which are affiliated with, but are distant to, a main renal centre. We considered whether constructing such units in rural regions of Ontario, Canada, alleviated under-service of rates of renal replacement therapy (RRT) locally, decreased patient travel distance and decreased local peritoneal dialysis (PD) utilization., Methods: We compared two groups of rural regions at two time points (years 1995 and 2002) in a before and after cross-sectional study. These regions were either already serviced by a satellite unit in 1995 (control group, 10 communities), or had new satellite units built between the years 1995 and 2002 (exposure group, 24 communities)., Results: The exposure group had a slightly greater increase in prevalent rate of RRT over time, but this did not reach statistical significance (control group increased 401 per million, exposure group 436 per million, P = 0.8). The mean weekly travel distance was reduced by 210.6 km after the construction of new satellite units (P < 0.001). There was no significant difference between the groups in reduction of PD proportion (P = 0.4). There was a significant increase in the number of elderly receiving RRT once local access was provided., Conclusions: In conclusion, constructing satellite units increased access to renal care for elderly patients and reduced travel time for HD patients living in rural communities.