Search

Prediction models are often developed in and applied to CKD populations. These models can be used to inform patients and clinicians about the potential risks of disease development or progression. With increasing availability of large datasets from CKD cohorts, there is opportunity to develop better prediction models that will lead to more informed treatment decisions. It is important that prediction modeling be done using appropriate statistical methods to achieve the highest accuracy, while avoiding overfitting and poor calibration. In this paper, we review prediction modeling methods in general from model building to assessing model performance as well as the application to new patient populations. Throughout, the methods are illustrated using data from the Chronic Renal Insufficiency Cohort Study., (Copyright © 2017 by the American Society of Nephrology.)

Interest in nephrology has been declining in recent years. Long work hours and a poor work/life balance may be partially responsible, and may also affect a fellowship's educational mission. We surveyed nephrology program directors using a web-based survey in order to define current clinical and educational practice patterns and identify areas for improvement. Our survey explored fellowship program demographics, fellows' workload, call structure, and education. Program directors were asked to estimate the average and maximum number of patients on each of their inpatient services, the number of patients seen by fellows in clinic, and to provide details regarding their overnight and weekend call. In addition, we asked about number of and composition of didactic conferences. Sixty-eight out of 148 program directors responded to the survey (46%). The average number of fellows per program was approximately seven. The busiest inpatient services had a mean of 21.5±5.9 patients on average and 33.8±10.7 at their maximum. The second busiest services had an average and maximum of 15.6±6.0 and 24.5±10.8 patients, respectively. Transplant-only services had fewer patients than other service compositions. A minority of services (14.5%) employed physician extenders. Fellows most commonly see patients during a single weekly continuity clinic, with a typical fellow-to-faculty ratio of 2:1. The majority of programs do not alter outpatient responsibilities during inpatient service time. Most programs (approximately 75%) divided overnight and weekend call responsibilities equally between first year and more senior fellows. Educational practices varied widely between programs. Our survey underscores the large variety in workload, practice patterns, and didactics at different institutions and provides a framework to help improve the service/education balance in nephrology fellowships., (Copyright © 2017 by the American Society of Nephrology.)

Background and Objectives: Despite the potential benefits of conservative management, providers rarely discuss it as a viable treatment option for patients with advanced CKD. This survey was to describe the knowledge, attitudes, and practices of nephrologists and primary care providers regarding conservative management for patients with advanced CKD in the United States., Design, Setting, Participants, & Measurements: We developed a questionnaire on the basis of a literature review to include items assessing knowledge, attitudes, and self-reported practices of conservative management for patients with advanced CKD. Potential participants were identified using the American Medical Association Physician Masterfile. We then conducted a web-based survey between April and May of 2015., Results: In total, 431 (67.6% nephrologists and 32.4% primary care providers) providers completed the survey for a crude response rate of 2.7%. The respondents were generally white, men, and in their 30s and 40s. Most primary care provider (83.5%) and nephrology (78.2%) respondents reported that they were likely to discuss conservative management with their older patients with advanced CKD. Self-reported number of patients managed conservatively was >11 patients for 30.6% of nephrologists and 49.2% of primary care providers. Nephrologists were more likely to endorse difficulty determining whether a patient with CKD would benefit from conservative management (52.8% versus 36.2% of primary care providers), whereas primary care providers were more likely to endorse limited information on effectiveness (49.6% versus 24.5% of nephrologists) and difficulty determining eligibility for conservative management (42.5% versus 14.3% of nephrologists). There were also significant differences in knowledge between the groups, with primary care providers reporting more uncertainty about relative survival rates with conservative management compared with different patient groups., Conclusions: Both nephrologists and primary care providers reported being comfortable with discussing conservative management with their patients. However, both provider groups identified lack of United States data on outcomes of conservative management and characteristics of patients who would benefit from conservative management as barriers to recommending conservative management in practice., (Copyright © 2016 by the American Society of Nephrology.)

Background and Objectives: We evaluated rates and factors associating with late referral (LR) and describe association of LR with access to renal transplantation and patient survival in children in the United Kingdom. Early requirement of RRT within 90 days of presentation to a pediatric nephrologist was classed as a LR, and those >90 days as an early referral (ER)., Design, Setting, Participants, & Measurements: We included patients who commenced RRT, aged ≥3 months and <16 years, from 1996 to 2012., Results: Of 1603 patients, 25.5% (n=408) were LR, of which 75% commenced RRT in <30 days following presentation. Those with LR were more likely to be older at presentation, female, and black. The primary renal disease in LR was more likely to be glomerular disease (odds ratio [OR], 1.6; 95% confidence interval [95% CI], 1.12 to 2.29), renal malignancy and associated diseases (OR, 4.11; 95% CI, 1.57 to 10.72), tubulo-interstitial diseases (OR, 2.37; 95% CI, 1.49 to 3.78), or an uncertain renal etiology (OR, 5.75; 95% CI, 3.1 to 10.65). Significant differences in rates of transplantation between LR and ER remained up to 1-year following commencement of dialysis (21% versus 61%, P<0.001) but with no differences for donor source (33.3% and 35.3% living donor in LR and ER respectively, P=0.55). The median (interquartile range) follow-up time was 4.8 years (2.9-7.6). There were 55 deaths with no statistically significant difference in survival in the LR group compared with the ER group (hazard ratio, 1.30; 95% CI, 0.7 to 2.3; P=0.40)., Conclusions: We found that 25% of children starting RRT in the United Kingdom receive a LR to pediatric renal services, with little change observed over the past two decades. Those with LR are unable to benefit from pre-emptive transplantation and require longer periods of dialysis before transplantation. There is an urgent need to understand causes of avoidable LR and develop strategies to improve kidney awareness more widely among health care professionals looking after children., (Copyright © 2016 by the American Society of Nephrology.)

Background and Objectives: In Canada, approximately 17% of patients use an arteriovenous access (fistula or arteriovenous graft) at commencement of hemodialysis, despite guideline recommendations promoting its timely creation and use. It is unclear if this low pattern of use is attributable to the lack of surgical creation or a high nonuse rate., Design, Setting, Participants, & Measurements: Using large health care databases in Ontario, Canada, a population-based cohort of adult patients (≥18 years old) who initiated hemodialysis as their first form of RRT between 2001 and 2010 was studied. The aims were to (1) estimate the proportion of patients who had an arteriovenous access created before starting hemodialysis and the proportion who successfully used it at hemodialysis start, (2) test for secular trends in arteriovenous access creation, and (3) estimate the effect of late nephrology referral and patient characteristics on arteriovenous access creation., Results: There were 17,183 patients on incident hemodialysis. The mean age was 65.8 years, 60% were men, and 40% were referred late to a nephrologist; 27% of patients (4556 of 17,183) had one or more arteriovenous accesses created, and the median time between arteriovenous access creation and hemodialysis start was 184 days. When late referrals were excluded, 39% of patients (4007 of 10,291) had one or more arteriovenous accesses created, and 27% of patients (2724 of 10,291) used the arteriovenous access. Since 2001, there has been a decline in arteriovenous access creation before hemodialysis initiation. Women, higher numbers of comorbidities, and rural residence were consistently associated with lower rates of arteriovenous access creation. These results persisted even after removing patients with <6 months nephrology care or who had AKI 6 months before starting hemodialysis., Conclusions: In Canada, arteriovenous access creation before hemodialysis initiation is low, even among patients followed by a nephrologist. Better understanding of the barriers and influencers of arteriovenous access creation is needed to inform both clinical care and guidelines., (Copyright © 2015 by the American Society of Nephrology.)

Background and Objectives: Disparities in kidney transplantation remain; one mechanism for disparities in access to transplantation (ATT) may be patient-perceived concerns about pursuing transplantation. This study sought to characterize prevalence of patient-perceived concerns, explore interrelationships between concerns, determine patient characteristics associated with concerns, and assess the effect of concerns on ATT., Design, Setting, Participants, & Measurements: Prevalences of 12 patient-perceived concerns about pursuing transplantation were determined among 348 adults who recently initiated dialysis, recruited from 26 free-standing dialysis centers around Baltimore, Maryland (January 2009-March 2012). Using variable reduction techniques, concerns were clustered into two categories (health-related and psychosocial) and quantified with scale scores. Associations between patient characteristics and concerns were estimated using modified Poisson regression. Associations between concerns and ATT were estimated using Cox models., Results: The most frequently cited patient-perceived concerns were that participants felt they were doing fine on dialysis (68.4%) and felt uncomfortable asking someone to donate a kidney (29.9%). Older age was independently associated with having high health-related (adjusted relative risk, 1.35 [95% confidence interval, 1.20 to 1.51], for every 5 years older for those ≥ 60 years) or psychosocial (1.15 [1.00 to 1.31], for every 5 years older for those aged ≥ 60 years) concerns, as was being a woman (1.72 [1.21 to 2.43] and 1.55 [1.09 to 2.20]), having less education (1.59 [1.08 to 2.35] and 1.77 [1.17 to 2.68], comparing postsecondary education to grade school or less), and having more comorbidities (1.18 [1.08 to 1.30] and 1.18 [1.07 to 1.29], per one comorbidity increase). Having never seen a nephrologist before dialysis initiation was associated with high psychosocial concerns (1.48 [1.01 to 2.18]). Those with high health-related (0.37 [0.16 to 0.87]) or psychosocial (0.47 [0.23 to 0.95]) concerns were less likely to achieve ATT (median follow-up time 2.2 years; interquartile range, 1.6-3.2)., Conclusions: Patient-perceived concerns about pursuing kidney transplantation are highly prevalent, particularly among older adults and women. Reducing these concerns may help decrease disparities in ATT., (Copyright © 2014 by the American Society of Nephrology.)

Missing data constitute a problem present in all studies of medical research. The most common approach to handling missing data-complete case analysis-relies on assumptions about missing data that rarely hold in practice. The implications of this approach are biased and inefficient descriptions of relationships of interest. Here, various approaches for handling missing data in clinical studies are described. In particular, this work promotes the use of multiple imputation methods that rely on assumptions about missingness that are more flexible than those assumptions relied on by the most common method in use. Furthermore, multiple imputation methods are becoming increasingly more accessible in mainstream statistical software packages, making them both a sound and practical choice. The use of multiple imputation methods is illustrated with examples pertinent to kidney research, and concrete guidance on their use is provided., (Copyright © 2014 by the American Society of Nephrology.)

To respond to the serious and underrecognized epidemic of kidney disease in the United States, the US Food and Drug Administration and the American Society of Nephrology have founded the Kidney Health Initiative-a public-private partnership designed to create a collaborative environment in which the US Food and Drug Administration and the greater kidney community can interact to optimize the evaluation of drugs, devices, biologics, and food products. The Kidney Health Initiative will bring together all the necessary stakeholders, including patients, regulators, industry, health care providers, academics, and other governmental agencies, to improve patient safety and foster innovation. This initiative is intended to enable the kidney community as a whole to provide the right drug, device, or biologic for administration to the right patient at the right time by fostering partnerships that will facilitate development and delivery of those products and addressing challenges that currently impede these goals.

Background and Objectives: Geographic and other variations in medical practices lead to differences in medical costs, often without a clear link to health outcomes. This work examined variation in the frequency of physician visits to patients receiving hemodialysis to measure the relative importance of provider practice patterns (including those patterns linked to geographic region) and patient health in determining visit frequency., Design, Setting, Participants, & Measurements: This work analyzed a nationally representative 2006 database of patients receiving hemodialysis in the United States. A variation decomposition analysis of the relative importance of facility, geographic region, and patient characteristics--including demographics, socioeconomic status, and indicators of health status--in explaining physician visit frequency variation was conducted. Finally, the associations between facility, geographic and patient characteristics, and provider visit frequency were measured using multivariable regression., Results: Patient characteristics accounted for only 0.9% of the total visit frequency variation. Accounting for case-mix differences, patients' hemodialysis facilities explained about 24.9% of visit frequency variation, of which 9.3% was explained by geographic region. Visit frequency was more closely associated with many facility and geographic characteristics than indicators of health status. More recent dialysis initiation and recent hospitalization were associated with decreased visit frequency., Conclusions: In hemodialysis, provider visit frequency depends more on geography and facility location and characteristics than patients' health status or acuity of illness. The magnitude of variation unrelated to patient health suggests that provider visit frequency practices do not reflect optimal management of patients on dialysis.

Background and Objectives: Pre-ESRD care is an important predictor of outcomes in patients undergoing long-term dialysis. This study examined the extent of variation in receiving pre-ESRD care and black-white disparities across urban and rural counties., Design, Setting, Participants, & Measurements: Participants were 404,622 non-Hispanic white and black patients aged >18 years who began dialysis between 2005 and 2010 and resided in 3076 counties from the U.S. Renal Data System. The counties were grouped into large metropolitan, medium/small metropolitan, suburban, and rural counties. Pre-ESRD care indicators included receipt of nephrologist care at least 6 or 12 months before ESRD, dietitian care, use of arteriovenous fistula at first outpatient dialysis session, and use of erythropoiesis-stimulating agents (ESAs) in patients with hemoglobin level < 10 g/dl., Results: Large metropolitan and rural counties had lower percentages of patients who received pre-ESRD nephrologist care (25.7% and 26.9% for nephrologist care > 12 months), compared with the higher percentage in medium/small metropolitan counties (31.6%; both P<0.001). For both races, nonmetropolitan patients had poorer access to dietitian care and lower ESA use than metropolitan patients. Consistently in all four geographic areas, black patients received less care than their white counterparts. The unadjusted odds ratios of black versus white patients in receiving nephrologist care for >12 months before ESRD were 0.66 (95% confidence interval [CI], 0.61-0.72) in large metropolitan counties and 0.79 (95% CI, 0.69-0.90) in rural counties. The patterns remained, albeit attenuated, after adjustment for patient factors., Conclusions: The receipt of pre-ESRD care, with blacks receiving less care, varies among geographic areas defined by urban/rural characteristics.

Background and Objectives: Prognosis in nondialysis chronic kidney disease (CKD) patients under regular nephrology care is rarely investigated. Design, setting, participants, & measurements We prospectively followed from 2003 to death or June 2010 a cohort of 1248 patients with CKD stages 3 to 5 and previous nephrology care ≥1 year in 25 Italian outpatient nephrology clinics. Cumulative incidence of ESRD or death before ESRD were estimated using the competing-risk approach., Results: Estimated rates (per 100 patient-years) of ESRD and death 8.3 (95% confidence interval [CI], 7.4 to 9.2) and 5.9 (95% CI 5.2 to 6.6), respectively. Risk of ESRD and death increased progressively from stages 3 to 5. ESRD was more frequent than death in stage 4 and 5 CKD, whereas the opposite was true in stage 3 CKD. Younger age, lower body mass index, proteinuria, and high phosphate predicted ESRD, whereas older age, diabetes, previous cardiovascular disease, ESRD, proteinuria, high uric acid, and anemia predicted death (P < 0.05 for all). Among modifiable risk factors, proteinuria accounted for the greatest contribution to the model fit for either outcome., Conclusions: In patients receiving continuity of care in Italian nephrology clinics, ESRD was a more frequent outcome than death in stage 4 and 5 CKD, but the opposite was true in stage 3. Outcomes were predicted by modifiable risk factors specific to CKD. Proteinuria used in conjunction with estimated GFR refined risk stratification. These findings provide information, specific to CKD patients under regular outpatient nephrology care, for risk stratification that complement recent observations in the general population.

Background and Objectives: Nephrogenic systemic fibrosis (NSF) is a disorder that can affect patients with renal dysfunction exposed to a gadolinium-based contrast agent (GBCA). Given the unique role nephrologists play in caring for patients at risk to develop NSF, this study surveyed their perceptions and practices regarding NSF., Design, Setting, Participants, & Measurements: An internet-based, cross-sectional survey of clinical nephrologists in the United States was performed. Perceptions and self-reported practices regarding NSF and local facility policies were assessed concerning GBCA use in renal dysfunction., Results: Of the 2310 eligible nephrologists e-mailed to participate in the survey, 171 (7.4%) responded. Respondents spent 85% of their time in direct patient care and 83% worked in private practice; 59% had cared for a patient with NSF. Although over 90% were aware of the morbidity and mortality associated with NSF, 31% were unaware of an association with specific GBCA brand and 50% believed chronic kidney disease stage 3 patients were at risk to develop NSF. Changes in facility policies concerning GBCA use in renal dysfunction were widespread (>90%). Most nephrologists (56%) felt that enacted policies were appropriate, yet 58% were uncertain if the changes had benefited patients., Conclusions: These results indicate that nephrologists are generally familiar with the risk factors and consequences of NSF, but their perceptions do not always align with current evidence. Local policy changes in GBCA use are pervasive. Most nephrologists are comfortable with these policy changes but have mixed feelings regarding their effectiveness.

Background and Objectives: Acute kidney injury (AKI) is associated with adverse outcomes in critically ill patients. The influence of preexisting chronic kidney disease (CKD) on AKI outcomes is unclear., Design, Setting, Participants, & Measurements: We analyzed data from a prospective observational cohort study of AKI in critically ill patients who received nephrology consultation: the Program to Improve Care in Acute Renal Disease. In-hospital mortality rate, length of stay, and dialysis dependence were compared in patients with and without a prior history of CKD, defined by an elevated serum creatinine, proteinuria, and/or abnormal renal ultrasound within a year before hospitalization. We hypothesized that patients with AKI and prior history of CKD would have lower mortality rates, shorter lengths of stay, and higher rates of dialysis dependence than patients without prior history of CKD., Results: Patients with AKI and a prior history of CKD were older and underwent nephrology consultation earlier in the course of AKI. In-hospital mortality rate was lower (31 versus 40%, P = 0.04), and median intensive care unit length of stay was 4.6 d shorter (14.7 versus 19.3 d, P = 0.001) in patients with a prior history of CKD. Among dialyzed survivors, patients with prior CKD were also more likely to be dialysis dependent at hospital discharge. Differences in outcome were most evident in patients with lower severity of illness., Conclusions: Among critically ill patients with AKI, those with prior CKD experience a lower mortality rate but are more likely to be dialysis dependent at hospital discharge. Future studies should determine optimal strategies for managing AKI with and without a prior history of CKD.

Background and Objectives: Academic nephrology faces increasing challenges in faculty hiring and development. However, it is unknown how these pressures have affected the number and demographics of academic nephrologists., Design, Setting, Participants, & Measurements: Using the Association of American Medical Colleges Faculty Roster database, changes were analyzed in MD nephrology, as well as other internal medicine subspecialty, faculty from 1998 to 2008., Results: There were 1315 full-time MD nephrology faculty in 2008; this fell by 4.9% over the past decade. There were fewer junior, and more senior, faculty over this period. This was associated with 12.4% fewer tenured, 22.3% fewer tenure track, and an 11.5% increase in nontenure track, academic nephrologists. Academic nephrologists who are U.S. medical school graduates declined by 11.9%, while those who were international medical school graduates increased by 13.2%; nephrology has a greater percentage of international medical school graduates than any other internal medicine subspecialty. Female nephrology faculty increased by 14.3%, while male faculty fell by 9.5%. Asian nephrology faculty increased by 41.3%, while Caucasians declined by 15.2%. Similar changes in all the above parameters were seen for most other internal medicine subspecialties. The nephrology research programs at the top 20 research institutions, as compared with all other nephrology programs, had a greater decline in total MD, male, tenure track, and junior faculty., Conclusions: These data suggest that the future of academic nephrology is at risk. The decline in nephrology faculty provides incentive for leaders in academic nephrology to improve recruiting and retention practices.

Background and Objectives: Many patients with chronic kidney disease (CKD) are seen by primary care physicians who may not be aware of indications or benefits of timely nephrologist referral. Late referral to a nephrologist may lead to suboptimal pre-end stage renal disease care and greater mortality. It is not known whether current postgraduate training adequately prepares a future internist in this aspect of CKD management., Design, Setting, Participants, and Measurements: The authors performed an online questionnaire survey of internal medicine residents in the United States to determine their perceptions of indications for nephrology referral in CKD management., Results: Four hundred seventy-nine residents completed the survey with postgraduate year (PGY) distribution of 166 PGY 1,187 PGY 2 and 126 PGY 3. Few residents chose nephrology referral for proteinuria (45%), uncontrolled hypertension (64%), or hyperkalemia (26%). Twenty-eight percent of the residents considered consulting a nephrologist for anemia of CKD, whereas 45% would do so for bone disorder of CKD. Most of the residents would involve a nephrologist at glomerular filtration rate (GFR) <30 ml/min/1.73 m(2) (90%) and for rapid decline in GFR (79%). Many residents would refer a patient for dialysis setup at GFR 15 to 30 ml/min/1.73 m(2) (59%); however, 18% would do so at GFR <15 ml/min/1.73 m(2). Presence of CKD clinic experience or an in-house nephrology fellowship program did not considerably change these perceptions., Conclusions: Results show that internal medicine residents have widely differing perceptions of indications for nephrology referral. Educational efforts during residency training to raise awareness and benefits of early referral may improve CKD management by facilitating better collaboration between internist and nephrologist.