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Recent efforts have standardized definitions and classification systems for acute kidney injury (AKI) and chronic kidney disease (CKD). These efforts have enhanced communication, recognition, and awareness of acute and CKDs and stimulated research on both disorders. However, abnormalities of kidney function and structure can occur that do not meet the current criteria for either disorder. Recognizing the need for a uniform approach encompassing both acute and chronic abnormalities of kidney function and structure, the Kidney Disease Improving Global Outcomes 2012 Clinical Practice Guideline for AKI Guidelines proposed an operational definition for acute kidney diseases and disorders (AKD) that encompasses both AKI and any newly recognized kidney disease that does not meet the current definitions for AKI or CKD. Recent commentaries have highlighted that it may be premature to adopt these criteria into clinical practice, but that they may be useful for application in epidemiologic studies. Future research is needed to better understand the clinical characteristics, incidence, and prognosis of AKD, as well as the implications of case identification based on the AKD criteria., (© 2015 S. Karger AG, Basel.)

Background: Lower estimated glomerular filtration rate (eGFR) on a single occasion is associated with risk of cardiovascular events; whether the degree of change in eGFR during a 1-year period adds prognostic information is unknown., Methods and Results: We included adults who had ≥2 outpatient eGFR measurements (≥6 months apart) during a 1-year accrual period in Alberta, Canada. According to recent guidelines, we used a change in eGFR category (≥90, 60 to 89, 45 to 59, 30 to 44, 15 to 29, and <15 mL/min per 1.73 m(2)), and the presence/absence of a ≥25% change from baseline to classify participants into 5 groups: certain drop, uncertain drop, stable (no change), uncertain rise, and certain rise. We calculated adjusted rates of cardiovascular events (per 10 000 person-years) for each group. We estimated the adjusted risks of cardiovascular events associated with each category of change in eGFR, in reference to stable kidney function. Among the 526 388 participants, 76.1% (n=400 560) had stable, 2.6% (n=13 668) had a certain drop, and 3.3% (n=17 499) had a certain rise in eGFR. Compared with participants with stable kidney function, adjusted risks of myocardial infarction, heart failure, and stroke were 27%, 51%, and 20% higher, respectively, for those with a certain drop in kidney function. After adjusting for the last eGFR at the end of the accrual period, the observed association diminished., Conclusion: Clinically relevant changes in eGFR are associated with increased risk of cardiovascular events. However, most of the apparent increase in risk can be accounted for by assessing comorbidity and baseline kidney function., (© 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Objectives: To examine the association of early invasive management of acute coronary syndrome with adverse renal outcomes and survival, and to determine whether the risks or benefits of early invasive management differ in people with pre-existing chronic kidney disease., Design: Propensity score matched cohort study., Setting: Acute care hospitals in Alberta, Canada, 2004-09., Participants: 10,516 adults with non-ST elevation acute coronary syndrome., Interventions: Participants were stratified by baseline estimated glomerular filtration rate and matched 1:1 on their propensity score for early invasive management (coronary catheterisation within two days of hospital admission)., Main Outcome Measures: Risks of acute kidney injury, kidney injury requiring dialysis, progression to end stage renal disease, and all cause mortality were compared between those who received early invasive treatment versus conservative treatment., Results: Of 10,516 included participants, 4276 (40.7%) received early invasive management. After using propensity score methods to assemble a matched cohort of conservative management participants with characteristics similar to those who received early invasive management (n=6768), early invasive management was associated with an increased risk of acute kidney injury (10.3% v 8.7%, risk ratio 1.18, 95% confidence interval 1.03 to 1.36; P=0.019), but no difference in the risk of acute kidney injury requiring dialysis (0.4% v 0.3%, 1.20, 0.52 to 2.78; P=0.670). Over a median follow-up of 2.5 years, the risk of progression to end stage renal disease did not differ between the groups (0.3 v 0.4 events per 100 person years, hazard ratio 0.91, 95% confidence interval 0.55 to 1.49; P=0.712); however, early invasive management was associated with reduced long term mortality (2.4 v 3.4 events per 100 person years, 0.69, 0.58 to 0.82; P<0.001). These associations were consistent among people with pre-existing reduced estimated glomerular filtration rate and with alternate definitions for early invasive management., Conclusions: Compared with conservative management, early invasive management of acute coronary syndrome is associated with a small increase in risk of acute kidney injury but not dialysis or long term progression to end stage renal disease.

Background: Contrast-induced acute kidney injury (CI-AKI) has been associated with mortality, although it has been suggested this association may be attributable to confounding. We performed a systematic review and meta-analysis to characterize the associations between CI-AKI and subsequent clinical outcomes., Methods and Results: We identified studies using MEDLINE (1950 to June 2011) and Embase (1980 to June 2011), manual bibliographic searches, and contact with experts. We included observational studies that characterized outcomes among patients with and without AKI (based on changes in serum creatinine) after coronary angiography. Eligible studies reported at least 1 of mortality, cardiovascular events, end-stage renal disease, or length of hospital stay. Thirty-nine observational studies met inclusion criteria. Of 34 studies reporting mortality (including 139 603 participants), 33 reported an increased risk of death in those with CI-AKI, although the effect size varied between studies (I(2)=93.5%). Between-study heterogeneity was partially explained by whether adjustment for confounding features was performed (11 studies without adjustment; pooled crude risk ratio, 8.19; 95% confidence interval, 4.30-15.60; I(2)=77.3% versus 23 studies with adjustment; pooled adjusted risk ratio, 2.39; 95% confidence interval, 1.98-2.90; I(2)=88.3%). CI-AKI was consistently associated with an increased risk of cardiovascular events in 14 studies, end-stage renal disease in 3 studies, and prolonged hospitalization in 11 studies., Conclusions: CI-AKI is associated with an increased risk of mortality, cardiovascular events, renal failure, and prolonged hospitalization. However, the association between CI-AKI and mortality is strongly confounded by baseline clinical characteristics that simultaneously predispose to both kidney injury and mortality, and the risk attributable to CI-AKI is much lower than that reported from unadjusted studies.

Background: Administrative data are commonly used for surveillance of chronic medical conditions. The purpose of this study was to determine the validity of an algorithm derived from administrative data for identifying chronic kidney disease (CKD) compared to the reference standard of estimated glomerular filtration rate (eGFR)., Methods: We identified adults from the province of Alberta with at least two outpatient serum creatinine measurements within a 1-year time period. Validity indices were estimated for CKD using up to 3 years of administrative data (physician billing claims and hospital discharge abstracts) for various case-definition combinations. For each algorithm, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated against two reference standard definitions of CKD (two eGFR measurements <60 mL/min/1.73m(2) or mean eGFR < 30 mL/min/1.73m(2))., Results: A total of 321 293 eligible subjects were identified. Irrespective of the algorithm, sensitivities for defining CKD (eGFR < 60 mL/min/1.73m(2)) using administrative codes were low. A case-definition algorithm employing two physician claims or one hospitalization within a 2-year period had sensitivity of 19.4%, specificity of 97.2%, PPV of 60.1% and NPV of 84.8% for detecting CKD. Estimates of sensitivity were higher when <30 mL/min/1.73m(2) was used as the reference standard, although PPVs were lower and consistently less than 50%., Conclusion: These results, using eGFR as a reference standard, suggest that administrative data have insufficient sensitivity and PPV for CKD surveillance, although they may be useful when highly specific algorithms are required for research purposes.

Background and Objectives: Most studies of chronic kidney disease (CKD) and outcomes focus on mortality and ESRD, with limited data on other adverse outcomes. This study examined the associations among proteinuria, eGFR, and adverse cardiovascular (CV) events., Design, Setting, Participants, & Measurements: This was a population-based longitudinal study with patients identified from province-wide laboratory data from Alberta, Canada, between 2002 and 2007. Selected for this study from a total of 1,526,437 patients were 920,985 (60.3%) patients with at least one urine dipstick measurement and 102,701 patients (6.7%) with at least one albumin-creatinine ratio (ACR) measurement. Time to hospitalization was considered for one of four indications: congestive heart failure (CHF), coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI), peripheral vascular disease (PVD), and stroke/transient ischemic attacks [TIAs] (cerebrovascular accident [CVA]/TIA)., Results: After a median follow-up of 35 months, in fully adjusted models and compared with patients with estimated GFR (eGFR) of 45 to 59 ml/min per 1.73 m(2) and no proteinuria, patients with heavy proteinuria by dipstick and eGFR ≥ 60 ml/min per 1.73 m(2) had higher rates of CABG/PCI and CVA/TIA. Similar results were obtained in patients with proteinuria measured by ACR., Conclusions: Risks of major CV events at a given level of eGFR increased with higher levels of proteinuria. The findings extend current data on risk of mortality and ESRD. Measurement of proteinuria is of incremental prognostic benefit at every level of eGFR. The data support use of proteinuria measurement with eGFR for definition and risk stratification in CKD.

Chronic kidney disease is a common disorder and its prevalence is increasing worldwide. Early diagnosis on the basis of presence of proteinuria or reduced estimated glomerular filtration rate could permit early intervention to reduce the risks of cardiovascular events, kidney failure, and death that are associated with chronic kidney disease. In developed countries, screening for the disorder is most efficient when targeted at high-risk groups including elderly people and those with concomitant illness (such as diabetes, hypertension, or cardiovascular disease) or a family history of chronic kidney disease, although the role of screening in developing countries is not yet clear. Effective strategies are available to slow the progression of chronic kidney disease and reduce cardiovascular risk. Treatment of high blood pressure is recommended for all individuals with, or at risk of, chronic kidney disease. Use of angiotensin-converting-enzyme inhibitors or angiotensin-receptor blockers is preferred for patients with diabetic chronic kidney disease or those with the proteinuric non-diabetic disorder. Glycaemic control can help prevent the onset of early stages of chronic kidney disease in individuals with diabetes. Use of statins and aspirin is beneficial for most patients with chronic kidney disease who are at high cardiovascular risk, although research is needed to ascertain how to best prevent cardiovascular disease in this cohort. Models of care that facilitate delivery of the many complex aspects of treatment simultaneously could enhance management, although effects on clinical outcomes need further assessment. Novel clinical methods to better identify patients at risk of progression to later stages of chronic kidney disease, including kidney failure, are needed to target management to high-risk subgroups., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Background and Objectives: Cardiovascular (CV) disease causes significant morbidity and mortality among the hemodialysis (HD) population. This meta-analysis was performed to determine whether angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) reduce fatal and nonfatal CV events and left ventricular (LV) mass in patients receiving HD., Design, Setting, Participants, & Measurements: Studies were identified by searching electronic databases, bibliographies, and conference proceedings. Two reviewers independently selected randomized controlled trials using ACEIs or ARBs compared with control among patients receiving HD. Studies were independently assessed for inclusion, quality, and data extraction. Random-effects models were used to estimate the pooled relative risk (RR) for CV outcomes and the weighted mean difference (WMD) for pooled change-from-baseline comparisons for LV mass for ACEI or ARB treated patients compared with control., Results: Compared with control, the RR of CV events associated with ACEI or ARB use was 0.66 [95% confidence interval (CI) 0.35 to 1.25; P = 0.20]. ACEI or ARB use resulted in a statistically significant reduction in LV mass, with a WMD of 15.4 g/m(2) (95% CI 7.4 to 23.3; P < 0.001)., Conclusions: Treatment with an ACEI or ARB reduced LV mass in patients receiving HD. However, their use was not associated with a statistically significant reduction in the risk of fatal and nonfatal CV events. Larger, high-quality trials in the HD population are required to determine if the effects of ACEI or ARB therapy on LV mass translate into decreased CV morbidity and mortality.

Context: Laboratory reporting of estimated glomerular filtration rate (GFR) has been widely implemented, with limited evaluation., Objective: To examine trends in nephrologist visits and health care resource use before and after estimated GFR reporting., Design, Setting, and Patients: Community-based cohort study (N = 1,135,968) with time-series analysis. Participants were identified from a laboratory registry in Alberta, Canada, and followed up from May 15, 2003, to March 14, 2007 (with estimated GFR reporting implemented October 15, 2004)., Main Outcome Measure: Nephrologist visits and patient management., Results: Following estimated GFR reporting, the rate of first outpatient visits to a nephrologist for patients with chronic kidney disease (CKD; estimated GFR <60 mL/min/1.73 m(2)) increased by 17.5 (95% confidence interval [CI], 16.5-18.6) visits per 10,000 CKD patients per month, corresponding to a relative increase from baseline of 68.4% (95% CI, 65.7%-71.2%). There was no association between estimated GFR reporting and rate of first nephrologist visit among patients without CKD. Among patients with an estimated GFR of less than 30 mL/min/1.73 m(2), the rate of first nephrologist visits increased by 134.4 (95% CI, 60.0-208.7) visits per 10,000 patients per month. This increase was predominantly seen in women, patients aged 46 to 65 years as well as those aged 86 years or older, and those with hypertension, diabetes, and comorbidity. Reporting of estimated GFR was not associated with increased rates of internal medicine or general practitioner visits or increased use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers among patients with CKD and proteinuria or the subgroup limited to patients with diabetes., Conclusions: Reporting of estimated GFR was associated with an increase in first nephrologist visits, particularly among patients with more severe kidney dysfunction, women, middle-aged and very elderly patients, and those with comorbidities. Any effect on outcomes remains to be shown.

Background: The Alberta Kidney Disease Network is a collaborative nephrology research organization based on a central repository of laboratory and administrative data from the Canadian province of Alberta., Description: The laboratory data within the Alberta Kidney Disease Network can be used to define patient populations, such as individuals with chronic kidney disease (using serum creatinine measurements to estimate kidney function) or anemia (using hemoglobin measurements). The administrative data within the Alberta Kidney Disease Network can also be used to define cohorts with common medical conditions such as hypertension and diabetes. Linkage of data sources permits assessment of socio-demographic information, clinical variables including comorbidity, as well as ascertainment of relevant outcomes such as health service encounters and events, the occurrence of new specified clinical outcomes and mortality., Conclusion: The unique ability to combine laboratory and administrative data for a large geographically defined population provides a rich data source not only for research purposes but for policy development and to guide the delivery of health care. This research model based on computerized laboratory data could serve as a prototype for the study of other chronic conditions.

Background: The effects of kidney disease on the risk of hospitalization or death from specific noncardiovascular causes, including pneumonia, are unclear. The objective of this study is to determine the associations between estimated glomerular filtration rate (eGFR) and hospitalization or death with pneumonia., Study Design: Retrospective cohort study., Setting & Participants: Community-based study from a Canadian health region of 252,516 participants with 1 or more outpatient serum creatinine measurements from July 1, 2003, to June 30, 2004, who were not receiving dialysis or kidney transplantation., Predictor: eGFR calculated by using the 4-variable Modification of Diet in Renal Disease Study equation., Outcomes: Hospitalization with pneumonia or death within 30 days after pneumonia hospitalization., Measurements: Cox proportional hazards models adjusted for age, sex, socioeconomic status, and comorbidities with censoring at death, initiation of renal replacement therapy, or emigration., Results: Lower eGFR was associated with increased risk of hospitalization with pneumonia, although the magnitude of effect varied with age. The risk associated with decreased eGFR was greatest in participants 18 to 54 years old; compared with participants with an eGFR of 60 to 104 mL/min/1.73 m(2), adjusted hazard ratios for hospitalization with pneumonia were 3.23 (95% confidence interval, 2.40 to 4.36) in those with eGFR of 45 to 59 mL/min/1.73 m(2), 9.67 (95% confidence interval, 6.36 to 14.69) for eGFR of 30 to 44 mL/min/1.73 m(2), and 15.04 (95% confidence interval, 9.64 to 23.47) for eGFR less than 30 mL/min/1.73 m(2). Associations became weaker with increasing age, although the graded inverse association between lower eGFR and risk remained for older participants. An age-dependent inverse relationship also was observed between eGFR and risk of death within 30 days of hospitalization with pneumonia., Limitations: Residual confounding caused by severity of illness or unmeasured comorbidities may be present., Conclusion: The risk of hospitalization and death with pneumonia is greater at lower eGFRs, especially in younger adults. This association may contribute to excess mortality in people with chronic kidney disease.

Background: Patients with end-stage renal disease requiring dialysis are at high risk for bloodstream infection and infection-related death. Whether patients with chronic kidney disease who are not receiving dialysis are also at increased risk of bloodstream infection is less clear., Methods: We examined the association between chronic kidney disease not being treated with dialysis and bloodstream infection in a cohort of patients 66 years or older. All patients required at least 1 outpatient serum creatinine measurement enabling estimation of glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease Study equation. Cox proportional hazards models with censoring at the initiation of renal replacement therapy or death were used to determine associations between eGFR, bloodstream infection, and death within 30 days of community-onset bloodstream infection, adjusting for potential confounders., Results: In 25 675 patients followed up for a median of 3.2 years, 797 developed at least 1 bloodstream infection, of which most (75%) were community-onset infections. Compared with patients with an eGFR of 60 mL/min/1.73 m(2) or higher, adjusted hazard ratios (95% confidence intervals) for bloodstream infection according to eGFR were, respectively, 1.24 (1.01-1.52), 1.59 (1.24-2.04), and 3.54 (2.69-4.69) in those with an eGFR of 45 to 59, 30 to 44, and less than 30 mL/min/1.73 m(2). The associations were consistent for both community-onset and nosocomial infections. Compared with patients with an eGFR of 60 mL/min/1.73 m(2) or higher, the risk of death within 30 days of community-onset bloodstream infection was significantly greater in those with an eGFR less than 30 mL/min/1.73 m(2) (hazard ratio, 4.10; 95% confidence interval, 2.06-8.14)., Conclusion: Older adults with chronic kidney disease not being treated with dialysis are at increased risk of bloodstream infection and of death following community-onset bloodstream infection.

Background There are no consensus definitions for evaluating kidney function recovery after acute kidney injury (AKI) and acute kidney disease (AKD), nor is it clear how recovery varies across populations and clinical subsets. We present a federated analysis of four population-based cohorts from Canada, Denmark and Scotland, 2011–18. Methods We identified incident AKD defined by serum creatinine changes within 48 h, 7 days and 90 days based on KDIGO AKI and AKD criteria. Separately, we applied changes up to 365 days to address widely used e-alert implementations that extend beyond the KDIGO AKI and AKD timeframes. Kidney recovery was based on resolution of AKD and a subsequent creatinine measurement below 1.2× baseline. We evaluated transitions between non-recovery, recovery and death up to 1 year; within age, sex and comorbidity subgroups; between subset AKD definitions; and across cohorts. Results There were 464 868 incident cases, median age 67–75 years. At 1 year, results were consistent across cohorts, with pooled mortalities for creatinine changes within 48 h, 7 days, 90 days and 365 days (and 95% confidence interval) of 40% (34%–45%), 40% (34%–46%), 37% (31%–42%) and 22% (16%–29%) respectively, and non-recovery of kidney function of 19% (15%–23%), 30% (24%–35%), 25% (21%–29%) and 37% (30%–43%), respectively. Recovery by 14 and 90 days was frequently not sustained at 1 year. Older males and those with heart failure or cancer were more likely to die than to experience sustained non-recovery, whereas the converse was true for younger females and those with diabetes. Conclusion Consistently across multiple cohorts, based on 1-year mortality and non-recovery, KDIGO AKD (up to 90 days) is at least prognostically similar to KDIGO AKI (7 days), and covers more people. Outcomes associated with AKD vary by age, sex and comorbidities such that older males are more likely to die, and younger females are less likely to recover. [ABSTRACT FROM AUTHOR]

Background. Acute kidney injury (AKI) is a serious complication of major noncardiac surgery. Risk prediction models for AKI following noncardiac surgery may be useful for identifying high-risk patients to target with prevention strategies. Methods. We conducted a systematic review of risk prediction models for AKI following major noncardiac surgery. MEDLINE, EMBASE, BIOSIS Previews and Web of Science were searched for articles that (i) developed or validated a prediction model for AKI following major noncardiac surgery or (ii) assessed the impact of a model for predicting AKI following major noncardiac surgery that has been implemented in a clinical setting. Results. We identified seven models from six articles that described a risk prediction model for AKI following major noncardiac surgeries. Three studies developed prediction models for AKI requiring renal replacement therapy following liver transplantation, three derived prediction models for AKI based on the Risk, Injury, Failure, Loss of kidney function, End-stage kidney disease (RIFLE) criteria following liver resection and one study developed a prediction model for AKI following major noncardiac surgical procedures. The final models included between 4 and 11 independent variables, and c-statistics ranged from 0.79 to 0.90. None of the models were externally validated. Conclusions. Risk prediction models for AKI after major noncardiac surgery are available; however, these models lack validation, studies of clinical implementation and impact analyses. Further research is needed to develop, validate and study the clinical impact of such models before broad clinical uptake. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: Our objective was to describe the current practice for initiation of RRT in this population. There is uncertainty regarding the optimal time to initiate renal replacement therapy (RRT) in critically ill patients with acute kidney injury (AKI). Methods: Prospective study of patients receiving RRT in 6 intensive care units (ICUs) at 3 hospitals from July 2007 to August 2008. We characterized factors associated with start of RRT and evaluated their relationship with mortality. Results: We included 234 patients. RRT was initiated 1 day (0-4) after ICU admission (median [interquartile range]). Median creatinine was 331 μmol/L (225-446 μmol/L), urea 22.9 mmol/L (13.9-32.9 mmol/L), and RIFLE-Failure in 76.9%. Of traditional indications, Pao 2/Fio 2 < 200 (54.5%) and oliguria (32.9%) were most common. ICU and hospital mortality were 45.3% and 51.9%, respectively. In adjusted analysis, mortality at RRT initiation was associated with creatinine <332 μmol/L (odds ratio [OR] 2.8; 95% confidence interval [CI] 1.5-5.4), change in urea from admission >8.9 mmol/L (OR 1.8; 95% CI, 1.0-3.4), urine output <82 mL/24 hours (OR 3.0; 95% CI, 1.4-6.5), fluid balance >3.0 L/24 hours (OR 2.3; 95% CI, 1.2-4.5), percentage of fluid overload >5% (OR 2.3; 95% CI, 1.2-4.7), 3 or more failing organs (OR 4.5; 95% CI, 1.2-4.2), Sequential Organ Failure Assessment score >14 (OR 2.3; 95% CI, 1.3-4.3), and start 4 days or more after admission (OR 4.3; 95% CI, 1.9-9.5). Mortality was higher as factors accumulated. Conclusion: In ICU patients requiring RRT, there was marked variation in factors that influence start of RRT. RRT initiation with fewer clinical triggers was associated with lower mortality. Timing of RRT may modify survival but requires appraisal in a randomized trial. [Copyright &y& Elsevier]

Acute kidney injury (AKI) is associated with high morbidity and mortality and consumes substantial health-care resources, particularly when renal replacement therapy is required. Randomized controlled trials (RCTs) have not identified the optimal mode of renal replacement for AKI in terms of clinically relevant endpoints such as patient survival or recovery of renal function. As for other complex health interventions, the costs and consequences of AKI treatment are relevant to health-care providers and decision makers aiming to maximize health outcomes despite fixed health resources. Studies from several different centers suggest that continuous renal replacement therapy (CRRT) is more costly than intermittent hemodialysis and less economically attractive than even intensive intermittent dialysis. On the other hand, while the incremental costs of providing CRRT are significant, they remain relatively small compared with the projected costs of providing chronic dialysis to survivors who do not recover renal function. Even small differences in the risk of chronic dialysis in survivors are likely to determine the economic attractiveness of the different types of renal replacement therapies. To clarify the true incremental cost-effectiveness of these therapies, future RCTs should collect data on long-term survival, the need for chronic dialysis, and detailed information on costs. [ABSTRACT FROM AUTHOR]

Background: The staging system for chronic kidney disease relies almost exclusively on estimated glomerular filtration rate (eGFR), although proteinuria is also associated with adverse outcomes. Objective: To validate a 5-category system for risk stratification based on the combination of eGFR and proteinuria. Design: Retrospective cohort study. Setting: A provincial laboratory registry in Alberta, Canada, and a representative sample of noninstitutionalized U.S. adults. Patients: A derivation data set of 474 521 adult outpatients, 2 independent internal validation cohorts with 51 356 and 460 623 patients, and an external validation cohort of 14 358 patients. Measurements: Glomerular filtration rate, estimated by using the Modification of Diet in Renal Disease Study equation, and proteinuria, measured by using urine albumin-to-creatinine ratio or dipstick urinalysis. Outcomes included all-cause mortality and a composite renal outcome of kidney failure or doubling of serum creatinine level. Results: Over a median follow-up of 38 months in the internal validation cohorts, higher risk categories (indicating lower eGFR or more proteinuria) were associated with a graded increase in the risk for the composite renal outcome. The projected number of U.S. adults assigned to risk categories 3 and 4 in the alternate system was 3.9 million, compared with 16.3 million assigned to stage 3 and 4 in the current staging system. The alternate system was more likely to correctly reclassify persons who did not develop the renal outcome than those who did, although some persons developed the renal outcome despite reclassification to a lower category. However, all analyses of patients reclassified to a lower category showed that substantially fewer such patients developed the renal outcome than did not. Correct reclassification by the alternate system was more likely when proteinuria was measured by using albumin-to-creatinine ratio than with dipstick testing, and also more likely for the composite renal outcome than for mortality. Limitation: The study had a short follow-up time. Conclusion: Using proteinuria in combination with eGFR may reduce unnecessary referrals for care at the cost of not referring or delaying referral for some patients who go on to develop kidney failure. Primary Funding Source: Alberta Heritage Foundation for Medical Research interdisciplinary research team grant. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

To determine whether acute kidney injury results in later long-term decline in kidney function we measured changes in kidney function over a 3-year period in adults undergoing coronary angiography who had serum creatinine measurements as part of their clinical care. Acute kidney injury was categorized by the magnitude of increase in serum creatinine (mild (50-99% or 0.3 mg/dl) and moderate or severe (100%)) within 7 days of coronary angiography. Compared to patients without acute kidney injury, the adjusted odds of a sustained decline in kidney function at 3 months following angiography increased more than 4-fold for patients with mild to more than 17-fold for those with moderate or severe acute kidney injury. Among those with an estimated glomerular filtration rate after angiography less than 90 ml/min per 1.73 m2, the subsequent adjusted mean rate of decline in estimated glomerular filtration rate during long-term follow-up (all normalized to 1.73 m2 per year) was 0.2 ml/min in patients without acute kidney injury, 0.8 ml/min following mild injury, and 2.8 ml/min following moderate to severe acute kidney injury. Thus, acute kidney injury following coronary angiography is associated with a sustained loss and a larger rate of future decline in kidney function. [ABSTRACT FROM AUTHOR]

The article offers information on a study which identified the relationship between reduced glomerular filtration rate (GFR), proteinuria and adverse clinical outcomes. The study conducted between 2002 and 2007 involved participants from a province-wide laboratory registry in Alberta. To determine proteinuria, researchers employed urine dipstick or albumin-creatinine ratio (ACR). Primary outcome measures include all-cause mortality, myocardial infarction and progression to kidney failure. Presented in details are the research findings.

Findings from observational studies have established that the arteriovenous fistula (AVF) is the preferred form of vascular access for chronic hemodialysis. Unfortunately, in a subset of patients with end-stage renal disease, an AVF cannot be placed or fails to mature. In these patients an alternate form of vascular access, either an arteriovenous graft (AVG) or central venous catheter (CVC) must be selected. In this review we discuss the findings and limitations of studies examining the effect of access type (AVG or CVC) on clinical endpoints including mortality, quality of life, occurrence of infections, as well as the impact of the different access types on resource requirements. Specifically, we examine whether findings from previous studies are valid and applicable to patients for whom an AVF is not possible, and outline the need for future randomized clinical trials addressing this question. [ABSTRACT FROM AUTHOR]

The article discusses research on the use of automated, electronic alerts in improving recognition and managing acute kidney injury. It references a study by F. P Wilson and colleague published in the periodical "Lancet." Topics include the primary outcome of the clinical trial, limitations of the trial design, and the finding that AKI alerts did not alter clinical outcomes.

The article presents information on a cohort study conducted at Alberta, Canada to evaluate renal outcomes in invasive versus conservative management of acute coronary syndrome. It informs that people who received early invasive management for the syndrome were prone to develop acute kidney injury. The results manifest that no acute kidney injury required dialysis or progressed to end stage renal disease.

In the past two decades, a substantial increase in the incidence of acute kidney injury (AKI) and kidney injury requiring dialysis has occurred in North America. This increase has coincided with an increase in the incidence of end-stage renal disease (ESRD), which has exceeded that expected based upon the prevalence of chronic kidney disease (CKD). In order to better understand the association between these conditions, there has been a proliferation of studies that have examined the risks of incident and progressive CKD following AKI. Animal studies have shown that failed differentiation of epithelial cells following renal ischaemia-reperfusion injury might lead to tubulointerstitial fibrosis, supporting a biological mechanism linking AKI and CKD. Strong and consistent associations between AKI and incident CKD, progression of CKD and incident ESRD have also been shown in epidemiological studies. In this Review, we summarize the wealth of available data on the relationship between AKI and CKD, and discuss the implications of these findings for the long-term clinical management of patients following AKI. We also identify areas of active investigation and future directions for research. [ABSTRACT FROM AUTHOR]

The article presents information on a cohort study to undermine the risk of coronary heart disease in patients with chronic kidney disease compared to diabetes. It informs that the study was undertaken in Alberta, Canada and highlights that the population-based cohort included the measurement of glomerular filtration rate (eGFR) and proteinuria. The findings of the study suggest that chronic kidney disease can be regarded as one of the factors for future coronary disease. INSET: Panel: Research in context.