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, 6573 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.

Whether the lower risk of mortality associated with arteriovenous fistula use in hemodialysis patients is due to the avoidance of catheters or if healthier patients are simply more likely to have fistulas placed is unknown. To provide clarification, we determined the proportion of access-related deaths in a retrospective cohort study of patients aged ≥18 years who initiated hemodialysis between 2004 and 2012 at five Canadian dialysis programs. A total of 3168 patients initiated dialysis at the participating centers; 2300 met our inclusion criteria. Two investigators independently adjudicated cause of death using explicit criteria and determined whether a death was access-related. We observed significantly lower mortality in individuals who underwent a predialysis fistula attempt than in those without a predialysis fistula attempt in patients aged <65 years (hazard ratio [HR], 0.49; 95% confidence interval [95% CI], 0.29 to 0.82) and in the first 2 years of follow-up in those aged ≥65 years (HR_{0–24 months}, 0.60; 95% CI, 0.43 to 0.84; HR_{24+ months}, 1.83; 95% CI, 1.25 to 2.67). Sudden deaths that occurred out of hospital accounted for most of the deaths, followed by deaths due to cardiovascular disease and infectious complications. We found only 2.3% of deaths to be access-related. In conclusion, predialysis fistula attempt may associate with a lower risk of mortality. However, the excess mortality observed in patients treated with catheters does not appear to be due to direct, access-related complications but is likely the result of residual confounding, unmeasured comorbidity, or treatment selection bias.

Background: Administrative health care databases offer an efficient and accessible, though as-yet unvalidated, approach to studying outcomes of patients with chronic kidney disease and end-stage renal disease (ESRD). The objective of this study is to determine the validity of outpatient physician billing derived algorithms for defining chronic dialysis compared to a reference standard ESRD registry. Methods: A cohort of incident dialysis patients (Jan. 1 - Dec. 31, 2008) and prevalent chronic dialysis patients (Jan 1, 2008) was selected from a geographically inclusive ESRD registry and administrative database. Four administrative data definitions were considered: at least 1 outpatient claim, at least 2 outpatient claims, at least 2 outpatient claims at least 90 days apart, and continuous outpatient claims at least 90 days apart with no gap in claims greater than 21 days. Measures of agreement of the four administrative data definitions were compared to a reference standard (ESRD registry). Basic patient characteristics are compared between all 5 patient groups. Results: 1,118,097 individuals formed the overall population and 2,227 chronic dialysis patients were included in the ESRD registry. The three definitions requiring at least 2 outpatient claims resulted in kappa statistics between 0.60-0.80 indicating "substantial" agreement. "At least 1 outpatient claim" resulted in "excellent" agreement with a kappa statistic of 0.81. Conclusions: Of the four definitions, the simplest (at least 1 outpatient claim) performed comparatively to other definitions. The limitations of this work are the billing codes used are developed in Canada, however, other countries use similar billing practices and thus the codes could easily be mapped to other systems. Our reference standard ESRD registry may not capture all dialysis patients resulting in some misclassification. The registry is linked to on-going care so this is likely to be minimal. The definition utilized will vary with the research objective.

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. 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. 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. 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.

The Kidney Failure Risk Equation (KFRE) predicts risk of progression to kidney failure and is used to guide clinical decisions for patients with chronic kidney disease (CKD). The KFRE was implemented to guide access to multidisciplinary care for CKD patients in Alberta, Canada, based on their 2-year risk of kidney failure. We used a mixed methods approach to investigate patients’ and providers’ perspectives and experiences 1 year following KFRE implementation. We conducted post-implementation interviews with multidisciplinary clinic providers and with low-risk patients who transitioned from multidisciplinary to general nephrology care. We also administered pre- and post-implementation patient care experience surveys, targeting both low-risk patients discharged to general nephrology and high-risk patients who remained in the multidisciplinary clinic, and provider job satisfaction surveys. Twenty-seven interviews were conducted (9 patients, 1 family member, 17 providers). Five categories were identified among patients and providers: targeted care; access to resources outside the multidisciplinary clinics; self-efficacy; patient reassurance and reduced stress; and transition process for low-risk patients Two additional categories were identified among providers only: anticipated concerns and job satisfaction. Patients and providers reported that the risk-based approach allowed the clinic to target care to those most likely to experience kidney failure and most likely to benefit from multidisciplinary care. While some participants indicated the risk-based model enhanced the sustainability of the clinics, others expressed concern that care for low-risk patients discharged from multidisciplinary care, or those now considered ineligible, may be inadequate. Overall, 413 patients completed the care experience survey and 73 providers completed the workplace satisfaction survey. The majority of patients were satisfied with their care in both periods with no overall differences. When considering the responses “Always” and “Often” together versus not, there were statistically significant improvements in domains of access to care, caring staff, and safety of care. There were no differences in healthcare providers’ job satisfaction following KFRE implementation. Patients and healthcare providers reported that the risk-based approach improved the focus of the multidisciplinary CKD clinics by targeting patients at highest risk, with survey results suggesting no difference in patient care experience or healthcare provider job satisfaction.