Nephrology Referral Based on Laboratory Values, Kidney Failure Risk, or Both: A Study Using Veterans Affairs Health System Data.

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.

National Estimates of CKD Prevalence and Potential Impact of Estimating Glomerular Filtration Rate Without Race.

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.

Laboratory-wide association study of survival with prostate cancer.

BACKGROUND: Estimates of overall patient health are essential to inform treatment decisions for patients diagnosed with cancer. The authors applied XWAS methods, herein referred to as "laboratory-wide association study (LWAS)", to evaluate associations between routinely collected laboratory tests and survival in veterans with prostate cancer. METHODS: The authors identified 133,878 patients who were diagnosed with prostate cancer between 2000 and 2013 in the Veterans Health Administration using any laboratory tests collected within 6 months of diagnosis (3,345,083 results). Using the LWAS framework, the false-discovery rate was used to test the association between multiple laboratory tests and survival, and these results were validated using training, testing, and validation cohorts. RESULTS: A total of 31 laboratory tests associated with survival met stringent LWAS criteria. LWAS confirmed markers of prostate cancer biology (prostate-specific antigen: hazard ratio [HR], 1.07 [95% confidence interval (95% CI), 1.06-1.08]; and alkaline phosphatase: HR, 1.22 [95% CI, 1.20-1.24]) as well laboratory tests of general health (eg, serum albumin: HR, 0.78 [95% CI, 0.76-0.80]; and creatinine: HR, 1.05 [95% CI, 1.03-1.07]) and inflammation (leukocyte count: HR, 1.23 [95% CI, 1.98-1.26]; and erythrocyte sedimentation rate: HR, 1.33 [95% CI, 1.09-1.61]). In addition, the authors derived and validated separate models for patients with localized and advanced disease, identifying 28 laboratory markers and 15 laboratory markers, respectively, in each cohort. CONCLUSIONS: The authors identified routinely collected laboratory data associated with survival for patients with prostate cancer using LWAS methodologies, including markers of prostate cancer biology, overall health, and inflammation. Broadening consideration of determinants of survival beyond those related to cancer itself could help to inform the design of clinical trials and aid in shared decision making. LAY SUMMARY: This article examined routine laboratory tests associated with survival among veterans with prostate cancer. Using laboratory-wide association studies, the authors identified 31 laboratory tests associated with survival that can be used to inform the design of clinical trials and aid patients in shared decision making.

The Urine Albumin-to-Creatinine Ratio and Kidney Function after Nephrectomy.

PURPOSE: Patients with kidney cancer are at risk for chronic kidney disease after radical and partial nephrectomy. We determined if the urine albumin-to-creatinine ratio is independently associated with progressive chronic kidney disease after nephrectomy. MATERIALS AND METHODS: We performed a cohort study based within a large, integrated health care system. We identified patients who underwent radical or partial nephrectomy from 2004 to 2014 with urine albumin-to-creatinine ratio measured in the 12 months before surgery. We fit multivariable models to determine if the urine albumin-to-creatinine ratio was associated with the time to chronic kidney disease progression (defined as reaching stage 4 or 5 chronic kidney disease, estimated glomerular filtration rate less than 30 ml/minute/1.73 m2). We performed a parallel analysis measuring the time to stage 3b, 4 or 5 chronic kidney disease (estimated glomerular filtration rate less than 45 ml/minute/1.73 m2) among patients with normal or near normal preoperative kidney function (estimated glomerular filtration rate 60 ml/minute/1.73 m2 or greater). We also examined the association between urine albumin-to-creatinine ratio and survival. RESULTS: A total of 1,930 patients underwent radical or partial nephrectomy and had preoperative urine albumin-to-creatinine ratio and preoperative and postoperative estimated glomerular filtration rate. Of these patients 658 (34%) and 157 (8%) had moderate (urine albumin-to-creatinine ratio 30 to 300 mg/gm) or severe albuminuria (urine albumin-to-creatinine ratio greater than 300 mg/gm), respectively. Albuminuria severity was independently associated with progressive chronic kidney disease after radical (moderate albuminuria HR 1.7, 95% CI 1.4-2.2; severe albuminuria HR 2.3, 95% CI 1.7-3.1) and partial nephrectomy (moderate albuminuria HR 1.8, 95% CI 1.2-2.7; severe albuminuria HR 4.3, 95% CI 2.7-7.0). Albuminuria was also associated with survival following radical and partial nephrectomy. CONCLUSIONS: In patients undergoing radical or partial nephrectomy the severity of albuminuria can stratify risk of progressive chronic kidney disease.

Medical Record Documentation of Goals-of-Care Discussions Among Older Veterans With Incident Kidney Failure.

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.

External Validation of the Prostate Cancer Specific Comorbidity Index: A Claims Based Tool for the Prediction of Life Expectancy in Men with Prostate Cancer.

PURPOSE: Accurate assessment of life expectancy is critical to treatment decision making in men with prostate cancer. We sought to externally validate the PCCI (Prostate Cancer Comorbidity Index) to predict long-term mortality in men with prostate cancer and make it operational using claims data. MATERIALS AND METHODS: We performed an observational study of 181,009 men with prostate cancer in the Veterans Affairs Health System who were diagnosed from 2000 to 2013. Overall mortality across the PCCI scores was analyzed using Kaplan-Meier and Cox proportional hazards analysis. Discrimination and calibration were measured using the C-index and the mean prediction error, respectively. RESULTS: Among men with a PCCI score of 0, 1-2, 3-4, 5-6, 7-9 and 10 or greater the 10-year overall mortality rate was 15%, 26%, 36%, 41%, 52% and 69%, respectively. Multivariable Cox analysis showed an increasing hazard of mortality with higher PCCI scores, including 1.22 (95% CI 1.18-1.27), 1.69 (95% CI 1.61-1.76), 2.08 (95% CI 2.00-2.17), 2.88 (95% CI 2.76-3.00) and 4.50 (95% CI 4.32-4.69) for a score of 1 to 2, 3 to 4, 5 to 6, 7 to 9 and 10 or greater, respectively. The C-index to predict overall mortality was 0.773. The mean absolute error to predict 10-year overall mortality was 0.032. Of the men with clinically localized disease, Gleason 6 or less with less than 10-year life expectancy and Gleason 7 or less with life expectancy less than 5 years as defined by the PCCI 3,999 of 12,185 (33%) and 1,038 of 3,930 (26%), respectively, underwent definitive local treatment. CONCLUSIONS: The PCCI is a claims based, externally validated tool to predict mortality in men with prostate cancer. Integrating the PCCI into clinical pathways may improve prostate cancer management through more accurate assessment of life expectancy.

Dialysis versus Medical Management at Different Ages and Levels of Kidney Function in Veterans with Advanced CKD.

Background Appropriate patient selection and optimal timing of dialysis initiation among older adults with advanced CKD are uncertain. We determined the association between dialysis versus medical management and survival at different ages and levels of kidney function.Methods We assembled a nationally representative 20% sample of United States veterans with eGFR<30 ml/min per 1.73 m2 between 2005 and 2010 (n=73,349), with follow-up through 2012. We used an extended Cox model to determine associations among the time-varying exposures, age (<65, 65-74, 75-84, and ≥85 years), eGFR (<6, 6-<9, 9-<12, 12-<15, and 15-<29 ml/min per 1.73 m2), and provision of dialysis, and survival.Result Over the mean±SEM follow-up of 3.4±2.2 years, 15% of patients started dialysis and 52% died. The eGFR at which dialysis, compared with medical management, associated with lower mortality varied by age (P<0.001). For patients aged <65, 65-74, 75-84, and ≥85 years, dialysis associated with lower mortality for those with eGFR not exceeding 6-<9, <6, 9-<12, and 9-<12 ml/min per 1.73 m2, respectively. Dialysis initiation at eGFR<6 ml/min per 1.73 m2 associated with a higher median life expectancy of 26, 25, and 19 months for patients aged 65, 75, and 85 years, respectively. When dialysis was initiated at eGFR 9-<12 ml/min per 1.73 m2, the estimated difference in median life expectancy was <1 year for these patients.Conclusions Provision of dialysis at higher levels of kidney function may extend survival for some older patients.

Incident CKD after Radical or Partial Nephrectomy.

The comparative effectiveness of partial nephrectomy versus radical nephrectomy to preserve kidney function has not been well established. We determined the risk of clinically significant (stage 4 and higher) CKD after radical or partial nephrectomy among veterans treated for kidney cancer in the Veterans Health Administration (2001-2013). Among patients with preoperative eGFR≥30 ml/min per 1.73 m2, the incidence of CKD stage 4 or higher after radical (n=9759) or partial nephrectomy (n=4370) was 7.9% overall. The median time to stage 4 or higher CKD after surgery was 5 months, after which few patients progressed. In propensity score-matched cohorts, partial nephrectomy associated with a significantly lower relative risk of incident CKD stage 4 or higher (hazard ratio, 0.34; 95% confidence interval [95% CI], 0.26 to 0.43, versus radical nephrectomy). In a parallel analysis of patients with normal or near-normal preoperative kidney function (eGFR≥60 ml/min per 1.73 m2), partial nephrectomy was also associated with a significantly lower relative risk of incident CKD stage 3b or higher (hazard ratio, 0.15; 95% CI, 0.11 to 0.19, versus radical nephrectomy) in propensity score-matched cohorts. Competing risk regression models produced consistent results. Finally, patients treated with a partial nephrectomy had reduced risk of mortality (hazard ratio, 0.55; 95% CI, 0.49 to 0.62). In conclusion, compared with radical nephrectomy, partial nephrectomy was associated with a marked reduction in the incidence of clinically significant CKD and with enhanced survival. Postoperative decline in kidney function occurred mainly in the first year after surgery and appeared stable over time.

The Research Implications of Prostate Specific Antigen Registry Errors: Data from the Veterans Health Administration.

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.

Receipt of Nephrology Care and Clinical Outcomes Among Veterans With Advanced CKD.

BACKGROUND: Clinical practice guidelines recommend referral to nephrology when estimated glomerular filtration rate (eGFR) decreases to <30mL/min/1.73m2; 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/1.73m2 for January 1, 2010, through December 31, 2010, and a prior eGFR<60mL/min/1.73m2, 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.

Biologic differences between peripheral and transition zone prostate cancer.

BACKGROUND: Prostate cancer arises in the transition zone (TZ) in approximately 20-25% of cases. Modern biopsy and surveillance protocols, and advances in prostate cancer imaging, have renewed interest in TZ prostate cancers. We compared TZ and PZ prostate cancer to determine if cancer location is independently associated with better outcomes. METHODS: We evaluated an expanded cohort of 1354 men who underwent radical prostatectomy between 1983 and 2003 with updated long-term clinical follow-up. Regression models were used to compare the volume of high-grade (Gleason 4 or 5) cancer and total cancer volume by location. Uni- and multi-variable logistic regression models tested the associations between cancer location and adverse pathologic features. Multivariable proportional hazard models were fit to examine cancer recurrence. RESULTS: Patients with TZ cancer presented with higher pre-operative serum PSA values (11.07 vs. 7.86 ng/ml) and larger total cancer volume (7.1 vs. 3.8 cc). Patients with TZ cancer had decreased odds of seminal vesicle invasion (OR 0.08, 95% CI 0.03, 0.21), extra-capsular extension (OR 0.56, 95% CI 0.35, 0.92), and lymphovascular invasion (OR 0.48, 95% CI 0.27, 0.87) in multivariable models. TZ cancers were independently associated with decreased hazard of tumor recurrence (HR 0.62, 95% CI 0.43, 0.90). CONCLUSIONS: TZ cancer prostate is associated with favorable pathologic features and better recurrence-free survival despite being diagnosed with larger cancers and higher PSA values. Tumor location should be taken into account when stratifying patient risk before and after prostatectomy, particularly with the evolving role of imaging in prostate cancer management.

Utilization of cytoreductive nephrectomy and patient survival in the targeted therapy era.

We sought to analyze utilization and survival outcomes of cytoreductive nephrectomy (CN) in patients with metastatic renal cell carcinoma (RCC) before and after introduction of targeted therapy. We identified patients with metastatic RCC between 1993 and 2010 in the SEER registry and examined temporal trends in utilization. We performed a joinpoint regression to determine when changes in utilization of CN occurred. We fitted multivariable proportional hazard models in full and propensity score-matched cohorts. We performed a difference-in-difference analysis to compare survival outcomes before and after introduction of targeted therapy. The proportion of patients undergoing CN increased from 1993 to 2004, from 29% to 39%. We identified a primary joinpoint of 2004, just prior to the introduction of targeted therapy. Beginning in 2005, there was a modest decrease in utilization of CN. CN was associated with a lower adjusted relative hazard (0.41, 95% confidence interval 0.34­0.43). Median survival among patients receiving CN increased in the targeted therapy era (19 vs. 13 months), while median survival among patients not receiving CN increased only slightly (4 vs. 3 months). Difference-in-difference analysis showed a significant decrease in hazard of death among patients who received CN in the targeted therapy era. Despite decreased utilization in the targeted therapy era, CN remains associated with improved survival. Prospective randomized trials are needed to confirm the benefit of CN among patients with metastatic RCC treated with novel targeted therapies.

Early virologic responses and hematologic safety of direct-acting antiviral therapies in veterans with chronic hepatitis C.

BACKGROUND & AIMS: There are limited data on the early effectiveness of direct-acting antiviral (DAA) therapies for patients with hepatitis C virus (HCV) infection in routine medical practice. We aimed to evaluate real-world experience with DAA-based regimens. METHODS: By using the Veterans Affairs' Clinical Case Registry, we conducted a prospective observational intent-to-treat analysis of veterans infected with HCV genotype 1 who began treatment with pegylated interferon, ribavirin, and boceprevir (BOC, n = 661) or telaprevir (TVR, n = 198) before January 2012. We determined rates of virologic response at treatment weeks 4, 8, 12, and 24; futility; early discontinuation; and adverse hematologic events. RESULTS: About one third of patients discontinued treatment by week 24 (30% BOC, 34% TVR). A higher percentage of treatment-naive, noncirrhotic patients receiving BOC had undetectable levels of virus at week 24 than patients receiving TVR (74% vs 60%; P = .03). There were no significant differences in rates of early response within subgroups of cirrhotic patients, prior relapsers, prior partial responders, or prior null responders. By week 24, treatment was determined to be futile for 14% of patients receiving BOC and 17% of those receiving TVR. No differences were observed in overall rates of anemia (50% BOC, 49% TVR) or thrombocytopenia (16% BOC, 18% TVR); higher rates of neutropenia were observed in BOC-treated patients (34% BOC, 21% TVR; P = .008). CONCLUSIONS: HCV-infected veterans treated in routine medical practice with DAA-based regimens (BOC or TVR) had rates of early response comparable with those reported in clinical trials. However, they had higher rates of futility and early discontinuation than clinical trial participants. Further studies are needed to determine rates of sustained viral response.

Assessment and utilization of rapid virologic response in US veterans with chronic hepatitis C: evaluating provider adherence to practice guidelines.

BACKGROUND AND GOALS: There are limited data on the extent to which medical providers adhere to practice guidelines for the antiviral treatment of patients with chronic hepatitis C virus (HCV) infection. As representative of overall provider adherence to practice guidelines, provider adherence to specific recommendations regarding rapid virologic response (RVR) was assessed. STUDY: From the Department of Veterans Affairs' Clinical Case Registry, all patients with HCV genotype 1 who initiated peginterferon and ribavirin between January 1, 2007 and December 31, 2008 were identified. The rate of testing for RVR was determined. Patient, provider, and facility characteristics were assessed to determine the factors that predicted improved provider adherence. For patients who achieved RVR, the overall treatment duration was calculated as a secondary measure of provider adherence. RESULTS: About one half of the cohort (54%) had HCV RNA testing for RVR. Among several significant predictors, testing for RVR was more likely in gastroenterology/hepatology specialty clinics, by midlevel providers such as nurse practitioners and physician assistants, and in facilities with a higher volume of HCV patients. Most patients who achieved RVR completed a treatment course within the recommended range. However, 27% of the cohort received more or less than the recommended duration of treatment, thereby unnecessarily increasing their risk for adverse events or decreasing their potential for cure. CONCLUSIONS: More aggressive education is needed to improve provider adherence to HCV antiviral treatment guidelines and optimize the outcomes of HCV patients, especially with the recent approval of complicated direct-acting antiviral regimens.

Hypocitraturia and Risk of Bone Disease in Patients With Kidney Stone Disease.

Patients with kidney stone disease are at higher risk for bone disease. Hypocitraturia is common in patients with kidney stone disease and a key risk factor for stone recurrence. In this retrospective cohort study, we sought to determine whether hypocitraturia is also a risk factor for incident bone disease in patients with kidney stone disease. We used nationwide data from the Veterans Health Administration and identified 9025 patients with kidney stone disease who had a 24-hour urine citrate measurement between 2007 and 2015. We examined clinical characteristics of patients by level of 24-hour urine citrate excretion (<200, 200-400, and >400 mg/d) and the time to osteoporosis or fracture according to 24-hour urine citrate excretion level. Almost one in five veterans with kidney stone disease and a 24-hour urine citrate measurement had severe hypocitraturia, defined as <200 mg/d. Patients with severe hypocitraturia were at risk for osteoporosis or fracture (hazard ratio [HR] = 1.23; confidence interval [CI] 1.03-1.48), but after adjustment for demographic factors, comorbid conditions, and laboratory abnormalities associated with hypocitraturia, the association was no longer statistically significant (HR = 1.18; CI 0.98-1.43). Our results in a predominantly male cohort suggest a modest association between hypocitraturia and osteoporosis or fracture; there are likely to be other explanations for the potent association between kidney stone disease and diminished bone health. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Treatment and Control of Hypertension Among Adults With Chronic Kidney Disease, 2011 to 2019.

BACKGROUND: Hypertension frequently accompanies chronic kidney disease (CKD) as etiology and sequela. We examined contemporary trends in hypertension treatment and control in a national sample of adults with CKD. METHODS: We evaluated 5% cross-sectional samples of adults with CKD between 2011 and 2019 in the Veterans Health Administration. We defined CKD as a sustained estimated glomerular filtration rate value <60 mL/min per 1.73 m2 or a urine albumin-to-creatinine ratio ≥30 mg/g. The main outcomes were blood pressure (BP) control, defined as a systolic BP <140 mm Hg and a diastolic BP <90 mm Hg based on the mean of monthly BP measurements, and prescriptions for antihypertensive medications. RESULTS: The annual samples ranged between n=22 110 and n=33 039 individuals, with a mean age of 72 years, 96% of whom were men. Between 2011 and 2014, the age-adjusted proportion of adults with controlled BP declined from 78.0% to 72.2% (P value for linear trend, <0.001), reached a nadir of 71.0% in 2015, and then increased to 72.9% by 2019 (P value for linear trend, <0.001). Among adults with BP above goal, the age-adjusted proportion who did not receive antihypertensive treatment increased throughout the decade from 18.8% to 21.6%, and the age-adjusted proportion who received ≥3 antihypertensive medications decreased from 41.8% to 36.3%. Prescriptions for first-line antihypertensive agents also decreased. CONCLUSIONS: Among adults with CKD treated in the Veterans Health Administration, the proportion with controlled BP declined between 2011 and 2015 followed by a modest increase, coinciding with fewer prescriptions for antihypertensive medications.

Prevalence of Apparent Treatment-Resistant Hypertension in Chronic Kidney Disease in Two Large US Health Care Systems.

BACKGROUND AND OBJECTIVES: More intensive BP goals have been recommended for patients with CKD. We estimated the prevalence of apparent treatment-resistant hypertension among patients with CKD according to the 2017 American College of Cardiology/American Heart Association (ACC/AHA; BP goal <130/80 mm Hg) and 2021 Kidney Disease Improving Global Outcomes (KDIGO; systolic BP <120 mm Hg) guidelines in two US health care systems. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We included adults with CKD (an eGFR <60 ml/min per 1.73 m2) and treated hypertension from Kaiser Permanente Southern California and the Veterans Health Administration. Using electronic health records, we identified apparent treatment-resistant hypertension on the basis of (1) BP above the goal while prescribed three or more classes of antihypertensive medications or (2) prescribed four or more classes of antihypertensive medications regardless of BP. In a sensitivity analysis, we required diuretic use to be classified as apparent treatment-resistant hypertension. We estimated the prevalence of apparent treatment-resistant hypertension per clinical guideline and by CKD stage. RESULTS: Among 44,543 Kaiser Permanente Southern California and 241,465 Veterans Health Administration patients with CKD and treated hypertension, the prevalence rates of apparent treatment-resistant hypertension were 39% (Kaiser Permanente Southern California) and 35% (Veterans Health Administration) per the 2017 ACC/AHA guideline and 48% (Kaiser Permanente Southern California) and 55% (Veterans Health Administration) per the 2021 KDIGO guideline. By requiring a diuretic as a criterion for apparent treatment-resistant hypertension, the prevalence rates of apparent treatment-resistant hypertension were lowered to 31% (Kaiser Permanente Southern California) and 23% (Veterans Health Administration) per the 2017 ACC/AHA guideline. The prevalence rates of apparent treatment-resistant hypertension were progressively higher at more advanced stages of CKD (34%/33%, 42%/36%, 52%/41%, and 60%/37% for Kaiser Permanente Southern California/Veterans Health Administration eGFR 45-59, 30-44, 15-29, and <15 ml/min per 1.73 m2, respectively) per the 2017 ACC/AHA guideline. CONCLUSIONS: Depending on the CKD stage, up to a half of patients with CKD met apparent treatment-resistant hypertension criteria.

Twenty-four-hour Urine Testing and Urinary Stone Disease Recurrence in Veterans.

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.

Renal Morbidity Following Radical Cystectomy in Patients with Bladder Cancer.

BACKGROUND: Patients with chronic kidney disease (CKD) are poor candidates for standard treatments for muscle-invasive bladder cancer (MIBC) and may be more likely to experience adverse outcomes when diagnosed with MIBC. OBJECTIVE: To investigate factors associated with the development of advanced CKD following radical cystectomy. DESIGN SETTING AND PARTICIPANTS: Using national Veterans Health Administration utilization files, we identified 3360 patients who underwent radical cystectomy for MIBC between 2004 and 2018. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We examined factors associated with the development of advanced CKD (estimated glomerular filtration rate [eGFR] of <30 ml/min/1.73 m2) after radical cystectomy using multivariable logistic and proportional hazard regression, with and without consideration of competing risks. We examined survival using Kaplan-Meier product limit estimates and proportional hazard regression. RESULTS AND LIMITATIONS: The median age at surgery was 67 yr and the mean preoperative eGFR was 69.1 ± 20.3 ml/min/1.73 m2. Approximately three out of ten patients (n = 962, 29%) progressed to advanced CKD within 12 mo. Older age (hazard ratio [HR] per 5-yr increase 1.15, 95% confidence interval [CI] 1.10-1.20), preoperative hydronephrosis (HR 1.50, 95% CI 1.29-1.76), adjuvant chemotherapy (HR 1.19, 95% CI 1.00-1.41), higher comorbidity index (HR 1.13, 95% CI 1.11-1.16 per point), and lower baseline kidney function (HR 0.75, 95% CI 0.73-0.78) were associated with the development of advanced CKD. Baseline kidney function at the time of surgery was associated with survival. Generalizability is limited due to the predominantly male cohort. CONCLUSIONS: Impaired kidney function at baseline is associated with progression to advanced CKD and mortality after radical cystectomy. Preoperative kidney function should be incorporated into risk stratification algorithms for patients undergoing radical cystectomy. PATIENT SUMMARY: Impaired kidney function at baseline is associated with progression to advanced chronic kidney disease and mortality after radical cystectomy.

Clinical laboratory tests associated with survival in patients with metastatic renal cell carcinoma: A Laboratory Wide Association Study (LWAS).

BACKGROUND: Prognostic models for patients with metastatic renal cell carcinoma (mRCC) include select laboratory values. These models have important limitations, including reliance on a limited array of laboratory tests, and use of dichotomous ("high-low") cutoffs. We applied a Laboratory-Wide Association Study (LWAS) framework to systematically evaluate common clinical laboratory results associated with survival for patients diagnosed with mRCC. METHODS: We used laboratory data for 3,385 patients diagnosed with mRCC from 2002 to 2017. We developed a LWAS framework, to examine the association with 53 common clinical laboratory tests results (641,712 measurements) and overall survival. We employed false-discovery rate to test the association of multiple laboratory tests with survival, and validated these results using 3 separate cohorts to generate a standardized hazard ratio (sHR), reported for a 1 standard deviation unit change in each laboratory test. RESULTS: The LWAS approach confirmed the association of laboratory values currently used in prognostic models with survival, including calcium (HR 1.35, 95%CI 1.24-1.48), leukocyte count (HR 1.40, 95%CI 1.30-1.51), platelet count (HR 1.36, 95%CI 1.27-1.51), and hemoglobin (HR 0.79, 95%CI 0.72-0.86). Use of these tests as continuous variables improved model performance. LWAS also identified acute phase reactants associated with survival not typically included in prognostic models, including serum albumin (HR 0.66, 95%CI 0.61-0.72), ferritin (HR 1.25, 95%CI 1.08-1.45), alkaline phosphatase (HR 1.31, 95%CI 1.23-1.40), and C-reactive protein (HR 1.70, 95%CI 1.14-2.53). CONCLUSIONS: Routinely measured laboratory tests can refine current prognostic models, facilitate comparisons across clinical trial cohorts, and match patients with specific systemic therapies.