Using Relative Survival to Estimate the Burden of Kidney Failure.

RATIONALE & OBJECTIVE: Estimates of mortality from kidney failure are misleading because the mortality from kidney failure is inseparable from the mortality attributed to comorbid conditions. We sought to develop an alternative method to reduce the bias in estimating mortality due to kidney failure using life table methods. STUDY DESIGN: Longitudinal cohort study. SETTING & PARTICIPANTS: Using data from the US Renal Data System and the Medicare 5% sample, we identified an incident cohort of patients, age 66+, who first had kidney failure in 2009 and a similar general population cohort without kidney failure. EXPOSURE: Kidney failure. OUTCOME: Death. ANALYTICAL APPROACH: We created comorbidity, age, sex, race, and year-specific life tables to estimate relative survival of patients with incident kidney failure and to attain an estimate of excess kidney failure-related deaths. Estimates were compared with those based on standard life tables (not adjusted for comorbidity). RESULTS: The analysis included 31,944 adults with kidney failure with a mean age of 77±7 years. The 5-year relative survival was 31% using standard life tables (adjusted for age, sex, race, and year) versus 36% using life tables also adjusted for comorbidities. Compared with other chronic diseases, patients with kidney failure have among the lowest relative survival. Patients with incident kidney failure ages 66-70 and 76-80 have a survival comparable to adults without kidney failure roughly 86-90 and 91-95 years old, respectively. LIMITATIONS: Relative survival estimates can be improved by narrowing the specificity of the covariates collected (eg, disease severity and ethnicity). CONCLUSIONS: Estimates of survival relative to a matched general population partition the mortality due to kidney failure from other causes of death. Results highlight the immense burden of kidney failure on mortality and the importance of disease prevention efforts among older adults. PLAIN-LANGUAGE SUMMARY: Estimates of death due to kidney failure can be misleading because death information from kidney failure is intertwined with death due to aging and other chronic diseases. Life tables are an old method, commonly used by actuaries and demographers to describe the life expectancy of a population. We developed life tables specific to a patient's age, sex, year, race, and comorbidity. Survival is derived from the life tables as the percentage of patients who are still alive in a specified period. By comparing survival of patients with kidney failure to the survival of people from the general population, we estimate that patients with kidney failure have one-third the chance of survival in 5 years compared with people with similar demographics and comorbidity but without kidney failure. The importance of this measure is that it provides a quantifiable estimate of the immense mortality burden of kidney failure.

Estimated Effect of Parathyroidectomy on Long-Term Kidney Function in Adults With Primary Hyperparathyroidism.

BACKGROUND: Multidisciplinary guidelines recommend parathyroidectomy to slow the progression of chronic kidney disease in patients with primary hyperparathyroidism (PHPT) and an estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m2. Limited data address the effect of parathyroidectomy on long-term kidney function. OBJECTIVE: To compare the incidence of a sustained decline in eGFR of at least 50% among patients with PHPT treated with parathyroidectomy versus nonoperative management. DESIGN: Target trial emulation was done using observational data from adults with PHPT, using an extended Cox model with time-varying inverse probability weighting. SETTING: Veterans Health Administration. PATIENTS: Patients with a new biochemical diagnosis of PHPT in 2000 to 2019. MEASUREMENTS: Sustained decline of at least 50% from pretreatment eGFR. RESULTS: Among 43 697 patients with PHPT (mean age, 66.8 years), 2928 (6.7%) had a decline of at least 50% in eGFR over a median follow-up of 4.9 years. The weighted cumulative incidence of eGFR decline was 5.1% at 5 years and 10.8% at 10 years in patients managed with parathyroidectomy, compared with 5.1% and 12.0%, respectively, in those managed nonoperatively. The adjusted hazard of eGFR decline did not differ between parathyroidectomy and nonoperative management (hazard ratio [HR], 0.98 [95% CI, 0.82 to 1.16]). Subgroup analyses found no heterogeneity of treatment effect based on pretreatment kidney function. Parathyroidectomy was associated with a reduced hazard of the primary outcome among patients younger than 60 years (HR, 0.75 [CI, 0.59 to 0.93]) that was not evident among those aged 60 years or older (HR, 1.08 [CI, 0.87 to 1.34]). LIMITATION: Analyses were done in a predominantly male cohort using observational data. CONCLUSION: Parathyroidectomy had no effect on long-term kidney function in older adults with PHPT. Potential benefits related to kidney function should not be the primary consideration for PHPT treatment decisions. PRIMARY FUNDING SOURCE: National Institute on Aging.

Kidney Disease, Hypertension Treatment, and Cerebral Perfusion and Structure.

RATIONALE & OBJECTIVE: The safety of intensive blood pressure (BP) targets is controversial for persons with chronic kidney disease (CKD). We studied the effects of hypertension treatment on cerebral perfusion and structure in individuals with and without CKD. STUDY DESIGN: Neuroimaging substudy of a randomized trial. SETTING & PARTICIPANTS: A subset of participants in the Systolic Blood Pressure Intervention Trial (SPRINT) who underwent brain magnetic resonance imaging studies. Presence of baseline CKD was assessed by estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (UACR). INTERVENTION: Participants were randomly assigned to intensive (systolic BP <120 mm Hg) versus standard (systolic BP <140 mm Hg) BP lowering. OUTCOMES: The magnetic resonance imaging outcome measures were the 4-year change in global cerebral blood flow (CBF), white matter lesion (WML) volume, and total brain volume (TBV). RESULTS: A total of 716 randomized participants with a mean age of 68 years were enrolled; follow-up imaging occurred after a median 3.9 years. Among participants with eGFR <60 mL/min/1.73 m2 (n = 234), the effects of intensive versus standard BP treatment on change in global CBF, WMLs, and TBV were 3.38 (95% CI, 0.32 to 6.44) mL/100 g/min, -0.06 (95% CI, -0.16 to 0.04) cm3 (inverse hyperbolic sine-transformed), and -3.8 (95% CI, -8.3 to 0.7) cm3, respectively. Among participants with UACR >30 mg/g (n = 151), the effects of intensive versus standard BP treatment on change in global CBF, WMLs, and TBV were 1.91 (95% CI, -3.01 to 6.82) mL/100 g/min, 0.003 (95% CI, -0.13 to 0.13) cm3 (inverse hyperbolic sine-transformed), and -7.0 (95% CI, -13.3 to -0.3) cm3, respectively. The overall treatment effects on CBF and TBV were not modified by baseline eGFR or UACR; however, the effect on WMLs was attenuated in participants with albuminuria (P = 0.04 for interaction). LIMITATIONS: Measurement variability due to multisite design. CONCLUSIONS: Among adults with hypertension who have primarily early kidney disease, intensive versus standard BP treatment did not appear to have a detrimental effect on brain perfusion or structure. The findings support the safety of intensive BP treatment targets on brain health in persons with early kidney disease. FUNDING: SPRINT was funded by the National Institutes of Health (including the National Heart, Lung, and Blood Institute; the National Institute of Diabetes and Digestive and Kidney Diseases; the National Institute on Aging; and the National Institute of Neurological Disorders and Stroke), and this substudy was funded by the National Institutes of Diabetes and Digestive and Kidney Diseases. TRIAL REGISTRATION: SPRINT was registered at ClinicalTrials.gov with study number NCT01206062.

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.

Association of Urine Biomarkers of Kidney Tubule Injury and Dysfunction With Frailty Index and Cognitive Function in Persons With CKD in SPRINT.

RATIONALE & OBJECTIVE: The associations of the glomerular markers of kidney disease, estimated glomerular filtration rate (eGFR) and albuminuria, with frailty and cognition are well established. However, the relationship of kidney tubule injury and dysfunction with frailty and cognition is unknown. STUDY DESIGN: Observational cross-sectional study. SETTING & PARTICIPANTS: 2,253 participants with eGFR<60mL/min/1.73m2 in the Systolic Blood Pressure Intervention Trial (SPRINT). EXPOSURE: Eight urine biomarkers: interleukin 18 (IL-18), kidney injury molecule 1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), chitinase-3-like protein 1 (YKL-40), monocyte chemoattractant protein 1 (MCP-1), α1-microglobulin (A1M), ß2-microglobulin (B2M), and uromodulin (Umod). OUTCOME: Frailty was measured using a previously validated frailty index (FI), categorized as fit (FI≤0.10), less fit (0.100.21). Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). ANALYTICAL APPROACH: Associations between kidney tubule biomarkers with categorical FI were evaluated using multinomial logistic regression with the fit group as the reference. Cognitive function was evaluated using linear regression. Models were adjusted for demographic, behavioral, and clinical variables including eGFR and urine albumin. RESULTS: Three of the 8 urine biomarkers of tubule injury and dysfunction were independently associated with FI. Each 2-fold higher level of urine KIM-1, a marker of tubule injury, was associated with a 1.22 (95% CI, 1.01-1.49) greater odds of being in the frail group. MCP-1, a marker of tubulointerstitial fibrosis, was associated with a 1.30 (95% CI, 1.04-1.64) greater odds of being in the frail group, and A1M, a marker of tubule reabsorptive capacity, was associated with a 1.48 (95% CI, 1.11-1.96) greater odds of being in the frail group. These associations were independent of confounders including eGFR and urine albumin, and were stronger than those of urine albumin with FI (1.15 [95% CI, 0.99-1.34]). Higher urine B2M, another marker of tubule reabsorptive capacity, was associated with worse cognitive scores at baseline (ß: -0.09 [95% CI, -0.17 to-0.01]). Urine albumin was not associated with cognitive function. LIMITATIONS: Cross-sectional design, and FI may not be generalizable in other populations. CONCLUSIONS: Urine biomarkers of tubule injury, fibrosis, and proximal tubule reabsorptive capacity are variably associated with FI and worse cognition, independent of glomerular markers of kidney health. Future studies are needed to validate these results among other patient populations.

Changes in brain functional connectivity and cognition related to white matter lesion burden in hypertensive patients from SPRINT.

PURPOSE: Hypertension is a risk factor for cognitive impairment; however, the mechanisms leading to cognitive changes remain unclear. In this cross-sectional study, we evaluate the impact of white matter lesion (WML) burden on brain functional connectivity (FC) and cognition in a large cohort of hypertensive patients from the Systolic Blood Pressure Intervention Trial (SPRINT) at baseline. METHODS: Functional networks were identified from baseline resting state functional MRI scans of 660 SPRINT participants using independent component analysis. WML volumes were calculated from structural MRI. Correlation analyses were carried out between mean FC of each functional network and global WML as well as WML within atlas-defined white matter regions. For networks of interest, voxel-wise-adjusted correlation analyses between FC and regional WML volume were performed. Multiple variable linear regression models were built for cognitive test performance as a function of network FC, followed by mediation analysis. RESULTS: Mean FC of the default mode network (DMN) was negatively correlated with global WML volume, and regional WML volume within the precuneus. Voxel-wise correlation analyses revealed that regional WML was negatively correlated with FC of the DMN's left lateral temporal region. FC in this region of the DMN was positively correlated to performance on the Montreal Cognitive Assessment and demonstrated significant mediation effects. Additional networks also demonstrated global and regional WML correlations; however, they did not demonstrate an association with cognition. CONCLUSION: In hypertensive patients, greater WML volume is associated with lower FC of the DMN, which in turn is related to poorer cognitive test performance. TRIAL REGISTRATION: NCT01206062.

End-of-Life Care among US Adults with ESKD Who Were Waitlisted or Received a Kidney Transplant, 2005-2014.

BACKGROUND: The care of patients in the United States who have ESKD is often shaped by their hopes and prognostic expectations related to kidney transplant. Little is known about how patients' engagement in the transplant process might relate to patterns of end-of-life care. METHODS: We compared six measures of intensity of end-of-life care among adults in the United States with ESKD who died between 2005 and 2014 after experiencing differing exposure to the kidney transplant process. RESULTS: Of 567,832 decedents with ESKD, 27,633 (5%) had a functioning kidney transplant at the time of death, 14,653 (3%) had a failed transplant, 16,490 (3%) had been removed from the deceased donor waitlist, 17,010 (3%) were inactive on the waitlist, 11,529 (2%) were active on the waitlist, and 480,517 (85%) had never been waitlisted for or received a transplant (reference group). In adjusted analyses, compared with the reference group, patients exposed to the transplant process were significantly more likely to have been admitted to an intensive care unit and to have received an intensive procedure in the last 30 days of life; they were also significantly more likely to have died in the hospital. Those who died on the transplant waitlist were also less likely than those in the reference group to have been enrolled in hospice and to have discontinued dialysis before death. CONCLUSIONS: Patients who had engaged in the kidney transplant process received more intensive patterns of end-of-life care than other patients with ESKD. These findings support the relevance of advance care planning, even for this relatively healthy segment of the ESKD population.

Racial and Sex Disparities in Catheter Use and Dialysis Access in the United States Medicare Population.

BACKGROUND: Despite efforts to increase arteriovenous fistula and graft use, 80% of patients in the United States start hemodialysis on a central venous catheter (CVC). METHODS: To better understand in incident hemodialysis patients how sex and race/ethnicity are associated with time on a central venous catheter and transition to an arteriovenous fistula and graft, our observational cohort study analyzed US Renal Data System data for patients with incident ESKD aged ≥66 years who started hemodialysis on a CVC in July 2010 through 2013. RESULTS: At 1 year, 32.7% of 74,194 patients transitioned to an arteriovenous fistula, 10.8% transitioned to an arteriovenous graft, 32.1% stayed on a CVC, and 24.5% died. Women spent a significantly longer time on a CVC than men. Compared with white patients, patients who were black, Hispanic, or of another racial/ethnicity minority spent significantly more days on a CVC. In competing risk regression, women were significantly less likely than men to transition to a fistula and more likely to transition to a graft. Compared with white patients, blacks were significantly less likely to transition to a fistula but more likely to transition to a graft, Hispanics were significantly more likely to transition to a fistula, and other races/ethnicities were significantly more likely to transition to either a fistula or a graft. CONCLUSIONS: Female patients spend a longer time on a CVC and are less likely to transition to permanent access. Compared with white patients, minorities also spend longer time on a CVC, but are more likely to eventually transition to permanent access. Strategies to speed transition to permanent access should target groups that currently lag in this area.

Kidney Disease, Intensive Hypertension Treatment, and Risk for Dementia and Mild Cognitive Impairment: The Systolic Blood Pressure Intervention Trial.

BACKGROUND: Intensively treating hypertension may benefit cardiovascular disease and cognitive function, but at the short-term expense of reduced kidney function. METHODS: We investigated markers of kidney function and the effect of intensive hypertension treatment on incidence of dementia and mild cognitive impairment (MCI) in 9361 participants in the randomized Systolic Blood Pressure Intervention Trial, which compared intensive versus standard systolic BP lowering (targeting <120 mm Hg versus <140 mm Hg, respectively). We categorized participants according to baseline and longitudinal changes in eGFR and urinary albumin-to-creatinine ratio. Primary outcomes were occurrence of adjudicated probable dementia and MCI. RESULTS: Among 8563 participants who completed at least one cognitive assessment during follow-up (median 5.1 years), probable dementia occurred in 325 (3.8%) and MCI in 640 (7.6%) participants. In multivariable adjusted analyses, there was no significant association between baseline eGFR <60 ml/min per 1.73 m2 and risk for dementia or MCI. In time-varying analyses, eGFR decline ≥30% was associated with a higher risk for probable dementia. Incident eGFR <60 ml/min per 1.73 m2 was associated with a higher risk for MCI and a composite of dementia or MCI. Although these kidney events occurred more frequently in the intensive treatment group, there was no evidence that they modified or attenuated the effect of intensive treatment on dementia and MCI incidence. Baseline and incident urinary ACR ≥30 mg/g were not associated with probable dementia or MCI, nor did the urinary ACR modify the effect of intensive treatment on cognitive outcomes. CONCLUSIONS: Among hypertensive adults, declining kidney function measured by eGFR is associated with increased risk for probable dementia and MCI, independent of the intensity of hypertension treatment.

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.

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.

Association of Intensive vs Standard Blood Pressure Control With Cerebral White Matter Lesions.

Importance: The effect of intensive blood pressure lowering on brain health remains uncertain. Objective: To evaluate the association of intensive blood pressure treatment with cerebral white matter lesion and brain volumes. Design, Setting, and Participants: A substudy of a multicenter randomized clinical trial of hypertensive adults 50 years or older without a history of diabetes or stroke at 27 sites in the United States. Randomization began on November 8, 2010. The overall trial was stopped early because of benefit for its primary outcome (a composite of cardiovascular events) and all-cause mortality on August 20, 2015. Brain magnetic resonance imaging (MRI) was performed on a subset of participants at baseline (n = 670) and at 4 years of follow-up (n = 449); final follow-up date was July 1, 2016. Interventions: Participants were randomized to a systolic blood pressure (SBP) goal of either less than 120 mm Hg (intensive treatment, n = 355) or less than 140 mm Hg (standard treatment, n = 315). Main Outcomes and Measures: The primary outcome was change in total white matter lesion volume from baseline. Change in total brain volume was a secondary outcome. Results: Among 670 recruited patients who had baseline MRI (mean age, 67.3 [SD, 8.2] years; 40.4% women), 449 (67.0%) completed the follow-up MRI at a median of 3.97 years after randomization, after a median intervention period of 3.40 years. In the intensive treatment group, based on a robust linear mixed model, mean white matter lesion volume increased from 4.57 to 5.49 cm3 (difference, 0.92 cm3 [95% CI, 0.69 to 1.14]) vs an increase from 4.40 to 5.85 cm3 (difference, 1.45 cm3 [95% CI, 1.21 to 1.70]) in the standard treatment group (between-group difference in change, -0.54 cm3 [95% CI, -0.87 to -0.20]). Mean total brain volume decreased from 1134.5 to 1104.0 cm3 (difference, -30.6 cm3 [95% CI, -32.3 to -28.8]) in the intensive treatment group vs a decrease from 1134.0 to 1107.1 cm3 (difference, -26.9 cm3 [95% CI, 24.8 to 28.8]) in the standard treatment group (between-group difference in change, -3.7 cm3 [95% CI, -6.3 to -1.1]). Conclusions and Relevance: Among hypertensive adults, targeting an SBP of less than 120 mm Hg, compared with less than 140 mm Hg, was significantly associated with a smaller increase in cerebral white matter lesion volume and a greater decrease in total brain volume, although the differences were small. Trial Registration: ClinicalTrials.gov Identifier: NCT01206062.

Palliative Care Disincentives in CKD: Changing Policy to Improve CKD Care.

The dominant health delivery model for advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD) in the United States, which focuses on provision of dialysis, is ill-equipped to address many of the needs of seriously ill patients. Although palliative care may address some of these gaps in care, its integration into advanced CKD care has been suboptimal due to several health system barriers. These barriers include uneven access to specialty palliative care services, underdeveloped models of care for seriously ill patients with advanced CKD, and misaligned policy incentives. This article reviews policies that affect the delivery of palliative care for this population, discusses reforms that could address disincentives to palliative care, identifies quality measurement issues for palliative care for individuals with advanced CKD and ESRD, and considers potential pitfalls in the implementation of new models of integrated palliative care. Reforming health care delivery in ways that remove policy disincentives to palliative care for patients with advanced CKD and ESRD will fill a critical gap in care.

Cognitive Impairment in Non-Dialysis-Dependent CKD and the Transition to Dialysis: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study.

BACKGROUND: Advanced chronic kidney disease is associated with elevated risk for cognitive impairment. However, it is not known whether and how cognitive impairment is associated with planning and preparation for end-stage renal disease. STUDY DESIGN: Retrospective observational study. SETTING & PARTICIPANTS: 630 adults participating in the CRIC (Chronic Renal Insufficiency Cohort) Study who had cognitive assessments in late-stage CKD, defined as estimated glome-rular filtration rate ≤ 20mL/min/1.73m2, and subsequently initiated maintenance dialysis therapy. PREDICTOR: Predialysis cognitive impairment, defined as a score on the Modified Mini-Mental State Examination lower than previously derived age-based threshold scores. Covariates included age, race/ethnicity, educational attainment, comorbid conditions, and health literacy. OUTCOMES: Peritoneal dialysis (PD) as first dialysis modality, preemptive permanent access placement, venous catheter avoidance at dialysis therapy initiation, and preemptive wait-listing for a kidney transplant. MEASUREMENTS: Multivariable-adjusted logistic regression. RESULTS: Predialysis cognitive impairment was present in 117 (19%) participants. PD was the first dialysis modality among 16% of participants (n=100), 75% had preemptive access placed (n=473), 45% avoided using a venous catheter at dialysis therapy initiation (n=279), and 20% were preemptively wait-listed (n=126). Predialysis cognitive impairment was independently associated with 78% lower odds of PD as the first dialysis modality (adjusted OR [aOR], 0.22; 95% CI, 0.06-0.74; P=0.02) and 42% lower odds of venous catheter avoidance at dialysis therapy initiation (aOR, 0.58; 95% CI, 0.34-0.98; P=0.04). Predialysis cognitive impairment was not independently associated with preemptive permanent access placement or wait-listing. LIMITATIONS: Potential unmeasured confounders; single measure of cognitive function. CONCLUSIONS: Predialysis cognitive impairment is associated with a lower likelihood of PD as a first dialysis modality and of venous catheter avoidance at dialysis therapy initiation. Future studies may consider addressing cognitive function when testing strategies to improve patient transitions to dialysis therapy.

The Association of Sleep Duration and Quality with CKD Progression.

Evidence suggests that sleep disorders are common in individuals with CKD, but the influence of sleep duration and quality on CKD progression is unknown. We examined the association of habitual sleep duration and quality with CKD progression in 431 Chronic Renal Insufficiency Cohort (CRIC) Study participants, of whom 48% were women and 50% had diabetes (mean age of 60 years old, mean eGFR =38 ml/min per 1.73 m2, and median urine protein-to-creatinine ratio [UPCR] =0.20 g/g). We assessed sleep duration and quality by 5-7 days of wrist actigraphy and self-report. Primary outcomes were incident ESRD, eGFR slope, log-transformed UPCR slope, and all-cause death. Participants slept an average of 6.5 hours per night; mean sleep fragmentation was 21%. Over a median follow-up of 5 years, we observed 70 ESRD events and 48 deaths. In adjusted analyses, greater sleep fragmentation associated with increased ESRD risk (hazard ratio, 1.04; 95% confidence interval, 1.01 to 1.07 per 1% increase in fragmentation). In adjusted mixed effects regression models, shorter sleep duration (per hour less) and greater sleep fragmentation (per 1% more) each associated with greater eGFR decline (-1.12 and -0.18 ml/min per 1.73 m2 per year, respectively; P=0.02 and P<0.01, respectively) and greater log UPCR slope (0.06/yr and 0.01/yr, respectively; P=0.02 and P<0.001, respectively). Self-reported daytime sleepiness associated with increased risk for all-cause death (hazard ratio, 1.11; 95% confidence interval, 1.02 to 1.20 per one-point increase in the Epworth Sleepiness Scale score). These findings suggest that short and poor-quality sleep are unrecognized risk factors for CKD progression.

Loss of executive function after dialysis initiation in adults with chronic kidney disease.

The association of dialysis initiation with changes in cognitive function among patients with advanced chronic kidney disease is poorly described. To better define this, we enrolled participants with advanced chronic kidney disease from the Chronic Renal Insufficiency Cohort in a prospective study of cognitive function. Eligible participants had a glomerular filtration rate of 20 ml/min/1.73m2 or less, or dialysis initiation within the past two years. We evaluated cognitive function by a validated telephone battery at regular intervals over two years and analyzed test scores as z scores. Of 212 participants, 123 did not transition to dialysis during follow-up, 37 transitioned to dialysis after baseline, and 52 transitioned to dialysis prior to baseline. In adjusted analyses, the transition to dialysis was associated with a significant loss of executive function, but no significant changes in global cognition or memory. The estimated net difference in cognitive z scores at two years for participants who transitioned to dialysis during follow-up compared to participants who did not transition to dialysis was -0.01 (95% confidence interval -0.13, 0.11) for global cognition, -0.24 (-0.51, 0.03) for memory, and -0.33 (-0.60, -0.07) for executive function. Thus, among adults with advanced chronic kidney disease, dialysis initiation was associated with loss of executive function with no change in other aspects of cognition. Larger studies are needed to evaluate cognition during dialysis initiation.

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.

Measures of Kidney Disease and the Risk of Venous Thromboembolism in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study.

BACKGROUND: Kidney disease has been associated with venous thromboembolism (VTE) risk, but results conflict and there is little information regarding blacks. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 30,239 black and white adults 45 years or older enrolled in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study 2003 to 2007. PREDICTORS: Estimated glomerular filtration rate (eGFR) using the combined creatinine-cystatin C (eGFRcr-cys) equation and urinary albumin-creatinine ratio (ACR). OUTCOMES: The primary outcome was adjudicated VTE, and secondary outcomes were provoked and unprovoked VTE, separately. Mortality was a competing-risk event. RESULTS: During 4.6 years of follow-up, 239 incident VTE events occurred over 124,624 person-years. Cause-specific HRs of VTE were calculated using proportional hazards regression adjusted for age, sex, race, region of residence, and body mass index. Adjusted VTE HRs for eGFRcr-cys of 60 to <90, 45 to <60, and <45 versus ≥90mL/min/1.73m2 were 1.28 (95% CI, 0.94-1.76), 1.30 (95% CI, 0.77-2.18), and 2.13 (95% CI, 1.21-3.76). Adjusted VTE HRs for ACR of 10 to <30, 30 to <300, and ≥300 versus <10mg/g were 1.14 (95% CI, 0.84-1.56), 1.15 (95% CI, 0.79-1.69), and 0.64 (95% CI, 0.25-1.62). Associations were similar for provoked and unprovoked VTE. LIMITATIONS: Single measurement of eGFR and ACR may have led to misclassification. Smaller numbers of events may have limited power. CONCLUSIONS: There was an independent association of low eGFR (<45 vs ≥90mL/min/1.73m2) with VTE risk, but no association of ACR and VTE.

Trends in Receipt of Intensive Procedures at the End of Life Among Patients Treated With Maintenance Dialysis.

BACKGROUND: Many dialysis patients receive intensive procedures intended to prolong life at the very end of life. However, little is known about trends over time in the use of these procedures. We describe temporal trends in receipt of inpatient intensive procedures during the last 6 months of life among patients treated with maintenance dialysis. STUDY DESIGN: Mortality follow-back study. SETTING & PARTICIPANTS: 649,607 adult Medicare beneficiaries on maintenance dialysis therapy who died in 2000 to 2012. PREDICTORS: Period of death (2000-2003, 2004-2008, or 2009-2012), age at time of death (18-59, 60-64, 65-69, 70-74, 75-79, 80-84, and ≥85 years), and race/ethnicity (Hispanic, non-Hispanic black, or non-Hispanic white). OUTCOME: Receipt of an inpatient intensive procedure (defined as invasive mechanical ventilation/intubation, tracheostomy, gastrostomy/jejunostomy tube insertion, enteral or parenteral nutrition, or cardiopulmonary resuscitation) during the last 6 months of life. RESULTS: Overall, 34% of cohort patients received an intensive procedure in the last 6 months of life, increasing from 29% in 2000 to 36% in 2012 (with 2000-2003 as the referent category; adjusted risk ratios [RRs] were 1.06 [95% CI, 1.05-1.07] and 1.10 [95% CI, 1.09-1.12] for 2004-2008 and 2009-2012, respectively). Use of intensive procedures increased more markedly over time in younger versus older patients (comparing 2009-2012 to 2000-2003, adjusted RR was 1.18 [95% CI, 1.15-1.20] for the youngest age group as opposed to 1.00 [95% CI, 0.96-1.04] for the oldest group). Comparing 2009 to 2012 to 2000 to 2003, the use of intensive procedures increased more dramatically for Hispanic patients than for non-Hispanic black or non-Hispanic white patients (adjusted RRs of 1.18 [95% CI, 1.14-1.22], 1.09 [95% CI, 1.07-1.11], and 1.10 [95% CI, 1.08-1.12], respectively). LIMITATIONS: Data sources do not provide insight into reasons for observed trends in the use of intensive procedures. CONCLUSIONS: Among patients treated with maintenance dialysis, there is a trend toward more frequent use of intensive procedures at the end of life, especially in younger patients and those of Hispanic ethnicity.

Cognitive Function and Kidney Disease: Baseline Data From the Systolic Blood Pressure Intervention Trial (SPRINT).

BACKGROUND: Chronic kidney disease is common and is associated with cardiovascular disease, cerebrovascular disease, and cognitive function, although the nature of this relationship remains uncertain. STUDY DESIGN: Cross-sectional cohort using baseline data from the Systolic Blood Pressure Intervention Trial (SPRINT). SETTING & PARTICIPANTS: Participants in SPRINT, a randomized clinical trial of blood pressure targets in older community-dwelling adults with cardiovascular disease, chronic kidney disease, or high cardiovascular disease risk and without diabetes or known stroke, who underwent detailed neurocognitive testing in the cognition substudy, SPRINT-Memory and Cognition in Decreased Hypertension (SPRINT-MIND). PREDICTORS: Urine albumin-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR). OUTCOMES: Cognitive function, a priori defined as 5 cognitive domains based on 11 cognitive tests using z scores, and abnormal white matter volume quantified by brain magnetic resonance imaging. RESULTS: Of 9,361 SPRINT participants, 2,800 participated in SPRINT-MIND and 2,707 had complete data; 637 had brain imaging. Mean age was 68 years, 37% were women, 30% were black, and 20% had known cardiovascular disease. Mean eGFR was 70.8±20.9mL/min/1.73m2 and median urine ACR was 9.7 (IQR, 5.7-22.5) mg/g. In adjusted analyses, higher ACR was associated with worse global cognitive function, executive function, memory, and attention, such that each doubling of urine ACR had the same association with cognitive performance as being 7, 10, 6, and 14 months older, respectively. Lower eGFR was independently associated with worse global cognitive function and memory. In adjusted models, higher ACR, but not eGFR, was associated with larger abnormal white matter volume. LIMITATIONS: Cross-sectional only, no patients with diabetes were included. CONCLUSIONS: In older adults, higher urine ACR and lower eGFR have independent associations with global cognitive performance with different affected domains. Albuminuria concurrently identifies a higher burden of abnormal brain white matter disease, suggesting that vascular disease may mediate these relationships.