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Rationale & Objective: Current guidelines for nephrology referral are based on laboratory criteria. We sought to evaluate whether nephrology referral patterns reflect current clinical practice guidelines and to estimate the change in referral volume if they were based on the estimated risk of kidney failure., Study Design: Observational cohort., Setting & Participants: Retrospective study of 399,644 veterans with chronic kidney disease (October 1, 2015 through September 30, 2016)., Exposure: Laboratory referral criteria based on Veterans Affairs/Department of Defense guidelines, categories of predicted risk for kidney failure using the Kidney Failure Risk Equation, and the combination of laboratory referral criteria and predicted risk., Outcome: Number of patients identified for referral., Analytical Approach: We evaluated the number of patients who were referred and their predicted 2-year risk for kidney failure. For each exposure, we estimated the number of patients who would be identified for referral., Results: There were 66,276 patients who met laboratory indications for referral. Among these patients, 11,752 (17.7%) were referred to nephrology in the following year. The median 2-year predicted risk of kidney failure was 1.5% (interquartile range, 0.3%-4.7%) among all patients meeting the laboratory referral criteria. If referrals were restricted to patients with a predicted risk of ≥1% in addition to laboratory indications, the potential referral volume would be reduced from 66,276 to 38,229 patients. If referrals were based on predicted risk alone, a 2-year risk threshold of 1% or higher would identify a similar number of patients (72,948) as laboratory-based criteria with median predicted risk of 2.3% (interquartile range, 1.4%-4.6%)., Limitations: Missing proteinuria measurements., Conclusions: The current laboratory-based guidelines for nephrology referral identify patients who are, on average, at low risk for progression, most of whom are not referred. As an alternative, referral based on a 2-year kidney failure risk exceeding 1% would identify a similar number of patients but with a higher median risk of kidney failure., (Published by Elsevier Inc.)

Background: The implications of removing the adjustment for Black race in equations to eGFR on the prevalence of CKD and management strategies are incompletely understood., Methods: We estimated changes in CKD prevalence and the potential effect on therapeutic drug prescriptions and prediction of kidney failure if race adjustment were removed from the CKD-EPI GFR estimating equation. We used cross-sectional and longitudinal data from adults aged ≥18 years in the National Health and Nutrition Examination Survey (NHANES) from 2015 to 2016, and the Veterans Affairs (VA) Health Care System in 2015. In the VA cohort, we assessed use of common medications that require dose adjustment on the basis of kidney function, and compared the prognostic accuracy of the Kidney Failure Risk Equation with versus without race adjustment of eGFR., Results: The prevalence of CKD among Black adults increased from 5.2% to 10.6% in NHANES, and from 12.4% to 21.6% in the VA cohort after eliminating race adjustment. Among Black veterans, 41.0% of gabapentin users, 33.5% of ciprofloxacin users, 24.0% of metformin users, 6.9% of atenolol users, 6.6% of rosuvastatin users, and 5.8% of tramadol users were reclassified to a lower eGFR for which dose adjustment or discontinuation is recommended. Without race adjustment of eGFR, discrimination of the Kidney Failure Risk Equation among Black adults remained high and calibration was marginally improved overall, with better calibration at higher levels of predicted risk., Conclusions: Removal of race adjustment from CKD-EPI eGFR would double the estimated prevalence of CKD among Black adults in the United States. Such a change is likely to affect a sizeable number of drug-dosing decisions. It may also improve the accuracy of kidney failure risk prediction among higher-risk Black adults., (Copyright © 2021 by the American Society of Nephrology.)

Whether a link exists between kidney stone disease and osteoporosis or fractures remains an open question. In this retrospective cohort study, we sought to determine the prevalence of osteoporosis and fractures and rate of bone mineral density screening by dual-energy X-ray absorptiometry (DXA) in patients with kidney stone disease. We examined nationwide data from the Veterans Health Administration and identified 531,431 patients with kidney stone disease between 2007 and 2015. Nearly 1 in 4 patients (23.6%, 95% confidence interval [CI] 23.5-23.7) with kidney stone disease had a prevalent diagnosis of osteoporosis or fracture. In patients with no prior history of osteoporosis or bone mineral density assessment before a kidney stone diagnosis, 9.1% were screened with DXA after their kidney stone diagnosis, of whom 20% were subsequently diagnosed with osteoporosis. Our findings provide support for wider use of bone mineral density screening in patients with kidney stone disease, including middle-aged and older men, a group less well recognized as at risk for osteoporosis or fractures. © 2021 American Society for Bone and Mineral Research (ASBMR)., (© 2021 American Society for Bone and Mineral Research (ASBMR).)

Importance: Current guidelines lack consensus regarding the treatment of patients who may not benefit from dialysis; this lack of consensus may be associated with the substantial variation in dialysis use and outcomes across health care facilities., Objective: To assess the degree to which variation in dialysis use and mortality was associated with patient rather than facility characteristics and to distinguish which features identified the US Department of Veterans Affairs (VA) facilities with high rates of dialysis use., Design, Setting, and Participants: This cohort study analyzed data of veterans with stage 3 or 4 chronic kidney disease that progressed to kidney failure between January 1, 2011, and December 31, 2014. These patients received care from VA facilities across the US. Data sources included laboratory and administrative records from the VA, Medicare, and United States Renal Data System. Data analysis was conducted from August 1, 2019, to September 1, 2020., Exposures: The primary exposure was the VA facility in which patients received most of their care before the onset of incident kidney failure defined as the first occurrence of either a sustained estimated glomerular filtration rate of less than 15 mL/min/1.73 m2 or the initiation of maintenance dialysis., Main Outcomes and Measures: The primary outcomes were dialysis use and mortality within 2 years of incident kidney failure. Median rate ratio was used to quantify facility-level variation, and variance partition coefficient was used to quantify the sources of unexplained variation., Results: The cohort included 8695 older veterans with a mean (SD) age of 78.8 (7.5) years who were predominantly male (8573 [99%]) and White (6102 [70%]) individuals treated at 108 VA facilities. The observed frequency of dialysis use across facilities ranged from 25.0% to 81.4%, with a median (interquartile range [IQR]) rate of 51.7% (48.4%-60.0%). The observed frequency of mortality across facilities ranged from 27.2% to 60.0%, with a median (IQR) rate of 45.2% (41.2%-48.6%). The median rate ratio (adjusted for multiple patient and facility characteristics) was 1.40 for dialysis use and 1.08 for mortality. The unexplained variation in both outcomes mainly derived from patient characteristics rather than facility characteristics. No correlation was found between dialysis use and mortality at the facility level (correlation coefficient = 0.03)., Conclusions and Relevance: This study found sizable variation in dialysis use for older adults that was poorly correlated with facility-level mortality rates and was not accounted for by differences in measured patient and facility characteristics. These findings suggest opportunities to improve the degree to which dialysis use practices align with the values, goals, and preferences of older adults with kidney failure.

Importance: Approximately 3% to 5% of patients with kidney stones have primary hyperparathyroidism (PHPT), a treatable cause of recurrent stones. However, the rate of screening for PHPT in patients with kidney stones remains unknown., Objectives: To estimate the prevalence of parathyroid hormone (PTH) testing in veterans with kidney stones and hypercalcemia and to identify the demographic, geographic, and clinical characteristics of veterans who were more or less likely to receive PTH testing., Design, Setting, and Participants: This cohort study obtained Veterans Health Administration (VHA) health records from the Corporate Data Warehouse for veterans who received care in 1 of the 130 VHA facilities across the United States from January 1, 2008, through December 31, 2013. Historical encounters, medical codes, and laboratory data were assessed. Included patients had diagnostic or procedural codes for kidney or ureteral stones, and excluded patients were those with a previous serum PTH level measurement. Data were collected from January 1, 2006, to December 31, 2014. Data analysis was conducted from June 1, 2019, to January 31, 2020., Exposures: Elevated serum calcium concentration measurement between 6 months before and 6 months after kidney stone diagnosis., Main Outcomes and Measures: Proportion of patients with a serum PTH level measurement and proportion of patients with biochemical evidence of PHPT who underwent parathyroidectomy., Results: The final cohort comprised 7561 patients with kidney stones and hypercalcemia and a mean (SD) age of 64.3 (12.3) years. Of these patients, 7139 were men (94.4%) and 5673 were white individuals (75.0%). The proportion of patients who completed a serum PTH level measurement was 24.8% (1873 of 7561). Across the 130 VHA facilities included in the study, testing rates ranged from 4% to 57%. The factors associated with PTH testing included the magnitude of calcium concentration elevation (odds ratio [OR], 1.07 per 0.1 mg/dL >10.5 mg/dL; 95% CI, 1.05-1.08) and the number of elevated serum calcium concentration measurements (OR, 1.08 per measurement >10.5 mg/dL; 95% CI, 1.06-1.10) as well as visits to both a nephrologist and a urologist (OR, 6.57; 95% CI, 5.33-8.10) or an endocrinologist (OR, 4.93; 95% CI, 4.11-5.93). Of the 717 patients with biochemical evidence of PHPT, 189 (26.4%) underwent parathyroidectomy within 2 years of a stone diagnosis., Conclusions and Relevance: This cohort study found that only 1 in 4 patients with kidney stones and hypercalcemia were tested for PHPT in VHA facilities and that testing rates varied widely across these facilities. These findings suggest that raising clinician awareness to PHPT screening indications may improve evaluation for parathyroidectomy, increase the rates of detection and treatment of PHPT, and decrease recurrent kidney stone disease.

Rationale & Objective: Elicitation and documentation of patient preferences is at the core of shared decision making and is particularly important among patients with high anticipated mortality. The extent to which older patients with incident kidney failure undertake such discussions with their providers is unknown and its characterization was the focus of this study., Study Design: Retrospective cohort study., Setting & Participants: A random sample of veterans 67 years and older with incident kidney failure receiving care from the US Veterans Health Administration between 2005 and 2010., Exposures: Demographic and facility characteristics, as well as predicted 6-month mortality risk after dialysis initiation and documentation of resuscitation preferences., Outcomes: Documented discussions of dialysis treatment and supportive care., Analytical Approach: We reviewed medical records over the 2 years before incident kidney failure and up to 1 year afterward to ascertain the frequency and timing of documented discussions about dialysis treatment, supportive care, and resuscitation. Logistic regression was used to identify factors associated with these documented discussions., Results: The cohort of 821 veterans had a mean age of 80.9±7.2 years, and 37.2% had a predicted 6-month mortality risk>20% with dialysis. Documented discussions addressing dialysis treatment and resuscitation were present in 55.6% and 77.1% of patients, respectively. Those addressing supportive care were present in 32.4%. The frequency of documentation varied by mortality risk and whether the patient ultimately started dialysis. In adjusted analyses, the frequency and pattern of documentation were more strongly associated with geographic location and receipt of outpatient nephrology care than with patient demographic or clinical characteristics., Limitations: Documentation may not fully reflect the quality and content of discussions, and generalizability to nonveteran patients is limited., Conclusions: Among older veterans with incident kidney failure, discussions of dialysis treatment are decoupled from other aspects of advance care planning and are suboptimally documented, even among patients at high risk for mortality., (Copyright © 2019 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Objective: The American Urological Association guidelines recommend 24-hour urine testing in patients with urinary stone disease to decrease the risk of stone recurrence; however, national practice patterns for 24-hour urine testing are not well characterized. Our objective is to determine the prevalence of 24-hour urine testing in patients with urinary stone disease in the Veterans Health Administration and examine patient-specific and facility-level factors associated with 24-hour urine testing. Identifying variations in clinical practice can inform future quality improvement efforts in the management of urinary stone disease in integrated healthcare systems., Materials and Methods: We accessed national Veterans Health Administration data through the Corporate Data Warehouse (CDW), hosted by the Veterans Affairs Informatics and Computing Infrastructure (VINCI), to identify patients with urinary stone disease. We defined stone formers as Veterans with one inpatient ICD-9 code for kidney or ureteral stones, two or more outpatient ICD-9 codes for kidney or ureteral stones, or one or more CPT codes for kidney or ureteral stone procedures from 2007 through 2013. We defined a 24-hour urine test as a 24-hour collection for calcium, oxalate, citrate or sulfate. We used multivariable regression to assess demographic, geographic, and selected clinical factors associated with 24-hour urine testing., Results: We identified 130,489 Veterans with urinary stone disease; 19,288 (14.8%) underwent 24-hour urine testing. Patients who completed 24-hour urine testing were younger, had fewer comorbidities, and were more likely to be White. Utilization of 24-hour urine testing varied widely by geography and facility, the latter ranging from 1 to 40%., Conclusions: Fewer than one in six patients with urinary stone disease complete 24-hour urine testing in the Veterans Health Administration. In addition, utilization of 24-hour urine testing varies widely by facility identifying a target area for improvement in the care of patients with urinary stone disease. Future efforts to increase utilization of 24-hour urine testing and improve clinician awareness of targeted approaches to stone prevention may be warranted to reduce the morbidity and cost of urinary stone disease., Competing Interests: The authors have declared that no competing interests exist.

Importance: The benefits of maintenance dialysis for older adults with end-stage renal disease (ESRD) are uncertain. Whether the setting of pre-ESRD nephrology care influences initiation of dialysis and mortality is not known., Objective: To compare initiation of dialysis and mortality among older veterans with incident kidney failure who received pre-ESRD nephrology care in fee-for-service Medicare vs the Department of Veterans Affairs (VA)., Design, Setting, and Participants: Retrospective cohort study of patients from the US Medicare and VA health care systems evaluated 11 215 veterans aged 67 years or older with incident kidney failure between January 1, 2008, and December 31, 2011. Data analysis was performed March 15, 2016, through September 20, 2017., Exposures: Pre-ESRD nephrology care in Medicare vs VA health care systems., Main Outcome and Measures: Dialysis treatment and death within 2 years., Results: Of the 11 215 patients included in the study, 11 085 (98.8%) were men; mean (SD) age was 79.1 (6.9) years. Within 2 years of incident kidney failure, 7071 (63.0%) of the patients started dialysis and 5280 (47.1%) died. Patients who received pre-ESRD nephrology care in Medicare were more likely to undergo dialysis compared with patients who received pre-ESRD nephrology care in VA (82% vs 53%; adjusted risk difference, 28 percentage points; 95% CI, 26-30 percentage points). Differences in dialysis initiation between Medicare and VA were more pronounced among patients aged 80 years or older and patients with dementia or metastatic cancer, and less pronounced among patients with paralysis (P < .05 for interaction). Two-year mortality was higher for patients who received pre-ESRD care in Medicare compared with VA (53% vs 44%; adjusted risk difference, 5 percentage points; 95% CI, 3-7 percentage points). The findings were similar in a propensity-matched analysis., Conclusions and Relevance: Veterans who receive pre-ESRD nephrology care in Medicare receive dialysis more often yet are also more likely to die within 2 years compared with those in VA. The VA's integrated health care system and financing appear to favor lower-intensity treatment for kidney failure in older patients without a concomitant increase in mortality.

Background: Clinical practice guidelines recommend referral to nephrology when estimated glomerular filtration rate (eGFR) decreases to <30mL/min/1.73m 2 ; however, evidence for benefits of nephrology care are mixed., Study Design: Observational cohort using landmark analysis., Settings & Participants: A national cohort of veterans with advanced chronic kidney disease, defined as an outpatient eGFR≤30mL/min/1.73m 2 for January 1, 2010, through December 31, 2010, and a prior eGFR<60mL/min/1.73m 2 , using administrative and laboratory data from the Department of Veterans Affairs and the US Renal Data System., Predictor: Receipt and frequency of outpatient nephrology care over 12 months., Outcomes: Survival and progression to end-stage renal disease (ESRD; receipt of dialysis or kidney transplantation) were the primary outcomes. In addition, control of associated clinical parameters over 12 months were intermediate outcomes., Results: Of 39,669 patients included in the cohort, 14,983 (37.8%) received nephrology care. Older age, heart failure, dementia, depression, and rapidly declining kidney function were independently associated with the absence of nephrology care. During a mean follow-up of 2.9 years, 14,719 (37.1%) patients died and 4,310 (10.9%) progressed to ESRD. In models adjusting for demographics, comorbid conditions, and trajectory of kidney function, nephrology care was associated with lower risk for death (HR, 0.88; 95% CI, 0.85-0.91), but higher risk for ESRD (HR, 1.48; 95% CI, 1.38-1.58). Among patients with clinical parameters outside guideline recommendations at cohort entry, a significantly higher adjusted proportion of patients who received nephrology care had improvement in control of hemoglobin, potassium, albumin, calcium, and phosphorus concentrations compared with those who did not receive nephrology care., Limitations: May not be generalizable to nonveterans., Conclusions: Among patients with advanced chronic kidney disease, nephrology care was associated with lower mortality, but was not associated with lower risk for progression to ESRD., (Copyright © 2017 National Kidney Foundation, Inc. All rights reserved.)

Objective: To determine whether 24-hour urine testing in Veterans with USD (urinary stone disease) reduces or delays urinary stone recurrence.Methods: Cohort study of national health record data from Veterans Health Administration from 2007 through 2013. We utilized a study population of 130,129 Veterans with USD based on diagnostic or procedural codes and excluded those with USD claims in the 2 years before cohort entry. We then created a propensity-score matched cohort of 14,854 Veterans based on completion of 24-hour urine testing within 6 months of stone diagnosis. Primary outcome was time-to-next clinically significant stone event, defined as an emergency department visit, inpatient admission related to a urinary stone, or urologic stone procedure with 5-year follow up.Results: Of 14,854 Veterans in the propensity-score matched cohort, 8560 (57.6%) experienced a recurrent USD event. Completion of 24-hour urine testing was associated with a higher risk of developing a second stone event (hazard ratio [HR] 1.17, 95% confidence interval [95% CI] 1.12-1.22). Among Veterans with known recurrent disease, we examined time to a third stone event. In this cohort of 4736 patients, completion of 24-hour urine testing was not associated with a higher risk of developing a third stone event (HR 1.06, 95% CI 0.99-1.12).Conclusion: Completion of 24-hour urine testing was not associated with a reduction in urinary stone recurrence. These findings challenge the validity of a longstanding recommendation in general medicine, nephrology, and urology practice. [ABSTRACT FROM AUTHOR]

Purpose We sought to characterize the effects of prostate specific antigen registry errors on clinical research by comparing cohorts based on cancer registry prostate specific antigen values with those based directly on results in the electronic health record. Materials and Methods We defined sample cohorts of men with prostate cancer using data from the Veterans Health Administration, including those with a prostate specific antigen value less than 4.0, 4.0 to 10.0, 10.0 to 20.0 and 20.0 to 98.0 ng/ml, respectively. We compared the composition of each cohort and overall patient survival when using prostate specific antigen values from the Veteran Affairs Central Cancer Registry vs the gold standard electronic health record laboratory file results. Results There was limited agreement among cohorts when defined by cancer registry prostate specific antigen values vs the laboratory file of the electronic health record. The least agreement of 58% was seen in patients with prostate specific antigen less than 4.0 ng/ml and greatest agreement of 89% was noted among patients with prostate specific antigen between 4.0 and 10.0 ng/ml. In each cohort patients assigned to a cohort based only on the cancer registry prostate specific antigen value had significantly different overall survival when compared with patients assigned based on registry and laboratory file prostate specific antigen values. Conclusions Cohorts based exclusively on cancer registry prostate specific antigen values may have high rates of misclassification that can introduce concerning differences in key characteristics and result in measurable differences in clinical outcomes. [ABSTRACT FROM AUTHOR]

Objective: To assess whether patient factors, such as age and preoperative kidney function, were associated with receipt of partial nephrectomy in a national integrated healthcare system.Materials and Methods: We identified patients treated with a radical or partial nephrectomy from 2002 to 2014 in the Veterans Health Administration. We examined associations among patient age, sex, race or ethnicity, multimorbidity, baseline kidney function, tumor characteristics, and receipt of partial nephrectomy. We estimated the odds of receiving a partial nephrectomy and assessed interactions between covariates and the year of surgery to explore whether patient factors associated with partial nephrectomy changed over time.Results: In our cohort of 14,186 patients, 4508 (31.2%) received a partial nephrectomy. Use of partial nephrectomy increased from 17% in 2002 to 32% in 2008 and to 38% in 2014. Patient race or ethnicity, age, tumor stage, and year of surgery were independently associated with receipt of partial nephrectomy. Black veterans had significantly increased odds of receipt of partial nephrectomy, whereas older patients had significantly reduced odds. Partial nephrectomy utilization increased for all groups over time, but older patients and patients with worse baseline kidney function showed the least increase in odds of partial nephrectomy.Conclusion: Although the utilization of partial nephrectomy increased for all groups, the greatest increase occurred in the youngest patients and those with the highest baseline kidney function. These trends warrant further investigation to ensure that patients at the highest risk of impaired kidney function are considered for partial nephrectomy whenever possible. [ABSTRACT FROM AUTHOR]