Impact of Poverty and Health Care Insurance on Arteriovenous Fistula Use among Incident Hemodialysis Patients.

BACKGROUND: The impact of socioeconomic factors on arteriovenous fistula (AVF) creation in hemodialysis (HD) patients is not well understood. We assessed the association of area and individual-level indicators of poverty and health care insurance on AVF use among incident end-stage renal disease (ESRD) patients initiated on HD. METHODS: In this retrospective cohort study using the United States Renal Data System database, we identified 669,206 patients initiated on maintenance HD from January 1, 2007 through December 31, 2012. We assessed the Medicare-Medicaid dual-eligibility status as an indicator of individual-level poverty and ZIP code-level median household income (MHI) data obtained from the 2010 United States Census. We conducted logistic regression of AVF use at start of dialysis as the outcome variable. RESULTS: The proportions of dual-eligible and non-dual-eligible patients who initiated HD with an AVF were 12.53 and 16.17%, respectively (p<0.001). Dual eligibility was associated with significantly lower likelihood of AVF use upon initiation of HD (adjusted odds ratio (aOR) 0.91; 95% CI 0.90-0.93). Patients in the lowest area-level MHI quintile had an aOR of 0.97 (95% CI 0.95-0.99) compared to those in higher quintile levels. However, dual eligibility and area-level MHI were not significant in patients with Veterans Affairs (VA) coverage. CONCLUSIONS: Individual- and area-level measures of poverty were independently associated with a lower likelihood of AVF use at the start of HD, the only exception being patients with VA health care benefits. Efforts to improve incident AVF use may require focusing on pre-ESRD care to be successful.

Racial variation in the development of posttransplant lymphoproliferative disorders after renal transplantation.

BACKGROUND: We previously reported that posttransplant lymphoproliferative disorders (PTLD) occurred more frequently in non-African American (AF) kidney transplant recipients. An in-depth analysis of racial differences in the development of PTLD has not been reported. METHODS: We assessed Medicare claims for PTLD in a retrospective cohort of 53,719 patients who underwent transplantation from January 2000 to September 2006 and followed up through December 2007. RESULTS: There were 719 (1.3%) patients with claims for PTLD. Non-AF recipient race (including all races analyzed separately, adjusted hazard ratio [AHR] 1.38, 95% confidence interval [CI] 1.13-1.68), recipient Epstein-Barr virus (EBV) immunoglobulin G (IgG) seronegative status (AHR 1.88, 95% CI 1.53-2.34), and de novo sirolimus (AHR 1.22, 95% CI 1.03-1.45) were associated with an increased risk of PTLD. Furthermore, de novo sirolimus showed a significant interaction with EBV IgG; among EBV IgG-negative recipients, sirolimus use was significant (P = 0.003), but among EBV IgG-positive recipients, it was not significant (P = 0.18). EBV IgG-seronegative status was significant in all races except for AFs, and racial differences were a significant effect modifier for EBV IgG status and risk of PTLD. Mortality subsequent to PTLD did not differ by race. CONCLUSIONS.: AF kidney transplant recipients were at lower risk for PTLD, irrespective of the recipient EBV IgG serostatus. On the contrary, recipient EBV IgG-seronegative status was associated with a higher risk of PTLD in the non-AF population. De novo sirolimus therapy was associated with increased risk of PTLD in EBV IgG-negative recipients, regardless of race.

Incidence, predictors and associated outcomes of renal cell carcinoma in long-term dialysis patients.

We carried out an analysis of the United States Renal Data System to determine the incidence, risk factors and prognosis of renal cell carcinoma (RCC) in a national population of patients receiving incident long-term dialysis. In Cox regression, male gender, older age, end-stage renal disease caused by obstruction, tuberous sclerosis, focal segmental glomerulosclerosis, as well as acquired renal cysts, were independently associated with RCC. Most cases of RCC in incident long-term dialysis patients occurred in patients without acquired renal cysts. A diagnosis of RCC was associated with increased risk of subsequent mortality overall and in all high-risk groups.

Outcomes associated with influenza vaccination in the first year after kidney transplantation.

BACKGROUND AND OBJECTIVES: Influenza vaccination is recommended in all renal transplant recipients. However, immunosuppression in the early period post-transplant may attenuate the immunologic response to the vaccine. Additionally, it has been theorized that vaccination can induce an immune response that could trigger rejection episodes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In a retrospective cohort of 51,730 adult Medicare primary patients who were first transplanted from January 2000 to July 2006 and followed through October 2006, we assessed Medicare claims for influenza vaccination and influenza infections, respectively. Outcomes included allograft loss and death. RESULTS: There were 9678 (18.7%) patients with claims for influenza vaccination in the first year post-transplant. Factors associated with vaccination included older age, diabetes, later year of transplant, and tacrolimus or mycophenolate at discharge. Vaccinations were less frequent among men, African Americans, highly sensitized patients, or those receiving induction immunosuppression or expanded criteria donor kidneys. Vaccination in the first year after transplant was associated with lower risk of subsequent allograft loss and death. Claims for influenza infection were reported in 310 (0.6%) patients and were not significantly associated with graft loss, although there was a trend toward death. CONCLUSIONS: In the first year after renal transplantation, influenza vaccination was associated with a lower risk of subsequent allograft loss and death. Although this study cannot comment on formation of protective antibodies after vaccination, these data do not support withholding vaccination on the basis of concerns of adversely affecting allograft function.

Poor outcomes associated with neutropenia after kidney transplantation: analysis of United States Renal Data System.

BACKGROUND: Posttransplant neutropenia (PTN) is relatively common after kidney transplantation, and may result in a reduction of immunosuppression, which may precipitate acute rejection. Granulocyte colony-stimulating factors (GCSF) have been used to treat PTN, although outcomes associated with use of this medication in this population are unknown. METHODS: In a retrospective cohort of 41,705 adult Medicare primary patients transplanted from January 2001 to June 2006, we assessed Medicare claims for neutropenia, leukopenia, and GCSF use, respectively. Outcomes included allograft loss and death. RESULTS: There were 6043 (14.5%) patients with claims for PTN. Factors associated with PTN included female gender, Caucasian ethnicity, ischemic heart disease, donor cytomegalovirus positive, deceased donor, expanded donor criteria, delayed graft function, elevated panel reactive antibody, higher human leukocyte antigen mismatch, and later year of transplant. Thymoglobulin induction, tacrolimus, and mycophenolate mofetil were also associated. PTN was less frequent among patients with congestive heart failure, recipient cytomegalovirus positive, and interleukin-2 induction. PTN was associated with increased risk of allograft loss (adjusted hazard ratio, 1.59; 95% confidence interval, 1.43-1.76; P<0.001) and death (adjusted hazard ratio, 1.74; 95% confidence interval, 1.59-1.90; P<0.001). Of the 6043 patients with PTN, 740 (12.2%) received GCSF. Patients who received GCSF had a lower risk of death on unadjusted analysis, but this only trended towards significance after adjustment. CONCLUSIONS: Neutropenia after renal transplantation is common and is associated with an increased risk of allograft loss and death. GCSF was used in 12% of cases and did not increase risk of allograft loss. Strategies to avoid PTN and greater use of GCSF may be indicated to prevent graft loss and death.

Arteriovenous fistulas among incident hemodialysis patients in Department of Defense and Veterans Affairs facilities.

A higher proportion of patients initiate hemodialysis (HD) with an arteriovenous fistula (AVF) in countries with universal health care systems compared with the United States. Because federally sponsored national health care organizations in the United States, such as the Department of Veterans Affairs (DVA) and the Department of Defense (DoD), are similar to a universal health care model, we studied AVF use within these organizations. We used the US Renal Data System database to perform a cross-sectional analysis of patients who initiated HD between 2005 and 2006. Patients who received predialysis nephrology care had 10-fold greater odds of initiating dialysis with an AVF (adjusted odds ratio [aOR] 10.3; 95% confidence interval [CI] 9.6 to 11.1). DVA/DoD insurance also independently associated with initiating HD with an AVF (aOR 1.4; 95% CI 1.2 to 1.5). Fewer patients initiated HD at a DoD facility, but these patients were also approximately twice as likely to use an AVF (aOR 2.3; 95% CI 1.2 to 4.6). In conclusion, patients in DVA/DoD systems are significantly more likely to use an AVF at initiation of HD than patients with other insurance types, including Medicare. Further study of these federal systems may identify practices that could improve processes of care across health care systems to increase the number of patients who initiate HD with an AVF.

Incidence, predictors, costs, and outcome of renal cell carcinoma after kidney transplantation: USRDS experience.

INTRODUCTION: We carried out an analysis of the United States Renal Data System to determine the incidence, risk factors, prognosis, and costs associated with the diagnosis of renal cell carcinoma (RCC) after kidney transplantation. METHODS: This is a retrospective cohort of 40,821 Medicare primary renal transplant recipients transplanted from January 1, 2000, to July 1, 2005, and followed up till December 31, 2005, excluding those with prior RCC or nephrectomy. Kaplan-Meier analysis was performed to determine the time of occurrence of RCC, and Cox regression was used to determine factors associated with RCC. RESULTS: Three hundred sixty-eight patients were diagnosed with RCC within 3 years after transplant (incidence of 3.16 per 1000 person years). The 3-year incidence of RCC posttransplant was 9.29 per 1000 person years (2.3%) for those with pretransplant cysts and 3.08 per 1000 person years (0.7%) without pretransplant cysts. RCC was diagnosed disproportionately early posttransplant in patients with cysts. Cysts were independently associated with increased risk of RCC, as was male gender, older recipient, donor age, African American recipient, increased time on dialysis and acute rejection within first year posttransplant. RCC was associated with increased risk of mortality with a higher risk with pretransplant cysts. Patients who developed RCC had higher cumulative median costs ($55,456 at 2 years) than those who did not develop RCC ($40,369). There was no "clustering" of RCC in individual states or centers more than would be expected by chance. CONCLUSION: RCC was diagnosed disproportionately early in patients with pretransplant renal cysts and was associated with a worse prognosis and increased costs.

Incidence, predictors and outcomes of transplant renal artery stenosis after kidney transplantation: analysis of USRDS.

OBJECTIVE: We analyzed the United States Renal Data System registry to study the risks, predictors, and outcomes of transplant renal artery stenosis (TRAS) in contemporary practice. METHODS: The study sampled comprised adults with Medicare primary insurance who received kidney transplants in 2000-2005. We examined associations of recipient, donor and transplant factors with time-to-TRAS by the Kaplan-Meier method and multivariate Cox regression. Survival analysis methods were employed to estimate graft survival after TRAS, and to model TRAS as a time-dependent outcome predictor. Kaplan-Meier analysis was used to estimate time to allograft loss in patients who did or did not have an angioplasty procedure for TRAS. RESULTS: There were 823 cases of TRAS among 41,867 transplant patients, with an incidence rate of 8.3 (95% CI 7.8-8.9) cases per 1,000 patient-years. Mean time to diagnosis of TRAS was 0.83 + or - 0.81 years after transplant. Factors associated with TRAS were older recipient and donor age, extended criteria donors, induction immunosuppression, delayed graft function, and ischemic heart disease. There was no association of TRAS with deceased donors, prolonged cold ischemia time, acute rejection or cytomegalovirus status. TRAS was associated with increased risk of graft loss (including death; adjusted hazard ratio 2.84, 95% CI 1.70-4.72). Among the 823 patients with TRAS, 145 (17.6%) underwent angioplasty. Graft survival after TRAS was not significantly different in patients treated with angioplasty compared to those without angioplasty. CONCLUSIONS: TRAS is an important complication that predicts adverse patient and graft outcomes. Treatment strategies for TRAS warrant prospective investigation in clinical trials.

Analysis of USRDS: incidence and risk factors for Pneumocystis jiroveci pneumonia.

BACKGROUND: To investigate the effect of modern immunosuppression on the incidence, risk factors, morbidity, and mortality of Pneumocystis pneumonia (PCP) in recipients of kidney transplants. METHODS: We conducted a retrospective cohort study of 32,757 Medicare primary transplant recipients in the United States Renal Data System from January 1, 2000 through July 31, 2004. PCP infection was defined by Medicare claims using International Classification of Disease, 9th Revision codes. The incidence of PCP infections, graft loss, and death were measured. RESULTS: There were a total of 142 cases (cumulative incidence 0.4%) of PCP after kidney transplantation during the study period. By using multivariate analysis with Cox regression, expanded criteria donor, donation after cardiac death, and earlier year of transplant were associated with development of PCP disease. Induction immunosuppression and acute rejections were not associated with risk for PCP infections. However, based on adjusted hazard ratio (AHR), maintenance immunosuppression regimens containing the combination of tacrolimus and sirolimus (AHR 3.60, confidence interval [CI] 2.03-6.39), Neoral and mycophenolate mofetil (AHR 2.09, CI 1.31-3.31), and sirolimus and mycophenolate mofetil (AHR 2.77, CI 1.40-5.47), were associated with development of PCP. As a time dependent variable, PCP was associated with an increased risk of both graft loss and death. CONCLUSION: PCP infections are rare in the modern era of prophylaxis; however, these infections are a serious risk factor for graft loss and patient death, in particular, in patients who are on sirolimus as part of the immunosuppressive regimen. The median time to development of PCP after transplant was 0.80+/-0.95 years, suggesting a longer period of PCP prophylaxis.

Incidence, predictors, and associated outcomes of prostatism after kidney transplantation.

BACKGROUND AND OBJECTIVES: Renal transplantation is increasingly performed in elderly patients, and the incidence of benign prostatic hyperplasia (BPH) increases with age. Anuric males on dialysis may have occult BPH and not develop obstructive symptoms until urine flow is restored after transplantation. If left untreated, BPH poses a risk for numerous complications, including acute urinary retention (AUR), recurrent urinary tract infections (UTI), and renal failure. The authors hypothesized that incident BPH after renal transplantation would adversely affect allograft survival. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Medicare claims for BPH, AUR, UTI, and prostate resection procedures (transurethral resection of the prostate; TURP) were assessed in a retrospective cohort of 23,622 adult male Medicare primary renal transplant recipients in the United States Renal Data System database who received transplants from 1 January 2000 to 31 July 2005 and followed through 31 December 2005. RESULTS: The 3-yr incidence of BPH post-transplant was 9.7%. The incidences of AUR, UTI, and TURP after BPH diagnosis (up to 3 yr posttransplant) were 10.3%, 6.5%, and 7.3% respectively, and each was significantly associated with BPH. Cox regression analysis showed that recipient age per year, later year of transplant, and dialysis vintage were associated with incident BPH. Using Cox nonproportional hazards regression, BPH was significantly associated with renal allograft loss (including death). CONCLUSIONS: BPH is common in males after renal transplant and is independently associated with AUR, UTI, and graft loss. It is unknown whether treatment of BPH, either medical or surgical, attenuates these risks.

Progressive multifocal leukoencephalopathy and use of mycophenolate mofetil after kidney transplantation.

Mycophenolate mofetil (MMF) use may be associated with progressive multifocal leukoencephalopathy (PML). We conducted a retrospective cohort study of 32,757 renal transplant recipients using the United States Renal Data System kidney transplant files for the incidence, prognosis, and clinical features associated with PML occurring after kidney transplant. Subjects were transplanted from January 1, 2000 to July 31, 2004 and followed through December 31, 2004. The incidence density of PML in MMF users was 14.4 cases/100,000 person-years at risk versus 0 for non-MMF users (P=0.11) by log rank test. Factors significantly associated with PML were BK virus infection (22.2% vs. 1.1%), pretransplant transfusion (75% vs. 34%), panel reactive antibody more than 20% (56% vs. 14%), and use of antirejection medications in the first year (33% vs. 9.2%), all P less than 0.05. PML is rare in the renal transplant population. There was no significant association between PML and MMF, but MMF use in this cohort is too high to accurately assess an association.

Assessment of racial disparities in chronic kidney disease stage 3 and 4 care in the department of defense health system.

BACKGROUND AND OBJECTIVES: Racial disparities in provision of healthcare are widespread in the United States but have not been specifically assessed in provision of chronic kidney disease (CKD) care. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted a retrospective cohort study of the clinical database used in a Department of Defense (DOD) medical system. Beneficiaries studied were DOD-eligible beneficiaries with CKD stage 3 (n = 7729) and 4 (n = 589) using the modified Modification of Diet in Renal Disease (MDRD)-estimated GFR formula but requiring manual correction for Black race. Compliance with selected Kidney Disease Outcomes Quality Initiative (KDOQI) CKD recommended targets (monitoring of recommended laboratory data, prescription of recommended medications, and referral to nephrology) was assessed over a 12-mo period, stratified by CKD stage. Logistic regression analysis was used to assess whether race (White, Black, or other) was independently associated with provider compliance with targets, adjusted for demographic factors and burden of comorbid conditions. RESULTS: Among the targets, only monitoring of LDL cholesterol was significantly less common among Blacks. For all other measures, compliance was either not significantly different or significantly higher for Black compared with White beneficiaries. However, patients categorized as "Other" race were in general less likely to achieve targets than Whites, and at stage 3 CKD significantly less likely to achieve targets for monitoring of phosphorous, hemoglobin, and vitamin D. CONCLUSIONS: In the DOD health system, provider compliance with selected CKD stage 3 and 4 targets was not significantly lower for Black beneficiaries than for Whites, with the exception of LDL cholesterol monitoring. Patients classified as Other race were generally less likely to achieve targets than Whites, in some patients significantly so.

Effects of urinary tract infection on outcomes after renal transplantation in children.

Urinary tract infection (UTI) is the most common infection after kidney transplantation. A previous analysis showed that late (>6 mo after transplantation) UTI is associated with earlier graft loss in adults. It was hypothesized that children who are younger than 18 yr would be at higher risk to develop UTI and develop graft loss after both early and late UTI. The US Renal Data System database was analyzed from 1996 to 2000 for Medicare claims (composite of inpatient and outpatient) for UTI up to 36 mo after transplantation. SPSS software and Cox regression models were used to determine association of UTI and age after adjustment for covariates. Early UTI was defined as occurring <6 mo after transplantation, and late UTI was defined as occurring > or =6 mo after transplantation. The risk for graft loss after early UTI was elevated in all children (adjusted hazard ratio [AHR] 5.47; 95% confidence interval [CI] 1.93 to 15.4; P < 0.001) but not after late UTI (AHR 2.09; 95% CI 0.56 to 7.80; P = 0.27). Risk for posttransplantation death was not increased significantly after either early UTI (AHR 1.23; 95% CI 0.37 to 4.08) or late UTI (relative risk 2.22; 95% CI 0.90 to 5.44). Boys aged 2 to 5 (versus age 13 to <18 years) were at significantly higher risk for UTI. In girls, only those in the youngest age category (0 to 1) had higher risk for UTI. Children are at greater risk for graft loss after early but not necessarily late UTI. UTI was not an independent predictor of death in this population.

Longitudinal study of racial and ethnic differences in developing end-stage renal disease among aged medicare beneficiaries.

Diabetes and hypertension are the leading causes of renal failure. This study investigated racial differences in developing ESRD by participants' diabetes and hypertension status. This longitudinal study included 1,306,825 Medicare beneficiaries who were aged > or =66 yr at the study start and followed up to 10 yr from January 1, 1993, for the development of ESRD or death. During the 10 yr, 0.93 patients per 100 received ESRD treatment. After adjustment for age and gender, among patients with diabetes, black patients were 2.4 to 2.7 times and other races/ethnicities 1.6 to 1.7 times more likely than white patients to develop ESRD. Among hypertensive patients, black patients were 2.5 to 2.9 and others 1.7 to 1.8 times more likely than white patients to develop ESRD. Among patients with neither diabetes nor hypertension, black patients were 3.5 and others 2.0 times more likely. Black men with diabetes were 1.9 to 2.1 and women 2.5 to 3.4 times more likely than their white counterparts to develop ESRD. Hypertensive black men were 2.1 to 2.2 and women 2.8 to 3.6 times more likely to develop ESRD. The same findings were noted in women of other races/ethnicities. Compared with white counterparts, mortality was higher for black patients in all cohorts but lower among patients with ESRD. Although they are leading causes for renal failure, diabetes and hypertension do not cause racial differences in developing ESRD. Minority women especially are at greater risk for ESRD than white women. Further studies are needed to determine whether earlier initiation of dialysis is a factor in higher ESRD incidence among minorities.

Dementia as a predictor of mortality in dialysis patients.

The life expectancy of patients who have dementia and are initiated on dialysis in the United States has not been described in the medical literature. A retrospective cohort study was conducted of 272,024 Medicare/Medicaid primary patients in the US Renal Data System who were started on ESRD therapy between April 1, 1995, and December 31, 1999, and followed through December 31, 2001. Cox regression was used to calculate adjusted hazard ratios for risk for death after initiation of dialysis for patients whose dementia was diagnosed before the initiation of dialysis as shown by Medicare claims. The average time to death for patients with dementia was 1.09 versus 2.7 yr (P < 0.001) with an adjusted hazard ratio of 1.87 (95% confidence interval 1.77 to 1.98). The 2-yr survival for patients with dementia was 24 versus 66% for patients without dementia (P < 0.001 via log rank test). Dementia that is diagnosed before initiation on dialysis is an independent risk factor for subsequent death. Such patients should be considered for time-limited trials of dialysis and careful discussion in choosing whether to pursue initiation of dialysis or palliative care.

Maintenance immunosuppression use and the associated risk of avascular necrosis after kidney transplantation in the United States.

BACKGROUND: Avascular necrosis (AVN) after renal transplantation has been largely attributed to the use of corticosteroids. However, other risk factors such as microvascular thrombosis and hyperlipidemia have been well described and may be of increased importance in the era of early steroid cessation and avoidance. We hypothesized that maintenance immunosuppressive medications known to be associated with these risk factors for AVN would also be associated with a higher risk of AVN. METHODS: By using the U.S. Renal Data System database, we studied 27,772 primary patients on Medicare who received a solitary kidney transplant between January 1, 1996, and July 31, 2000. Cox proportional hazards regression models were used to calculate adjusted hazard ratios (AHRs) for patient- and transplant-related factors (including allograft rejection) with Medicare claims for AVN. The intensity and duration of corticosteroid use could not be assessed. RESULTS: Among patients who were prescribed sirolimus at discharge, 3.5% of patients who received the combination of sirolimus-cyclosporine A (CsA) demonstrated AVN, compared with 1.4% of patients who received the combination of sirolimus-tacrolimus (P=0.06 by chi). In Cox regression, CsA use (vs. tacrolimus) (AHR 1.36, 95% confidence interval, 1.09-1.71) was independently associated with an increased risk of AVN. Sirolimus use showed a trend toward significance (AHR 1.59, 95% confidence interval, 0.99-2.56), with no significant interaction with CsA. CONCLUSIONS: Compared with other maintenance immunosuppression, AVN was significantly more common after use of CsA prescribed at the time of discharge for renal transplantation. Whether this increased risk of AVN was directly attributable to hyperlipidemia, microvascular thrombosis, or differences in corticosteroid dosing could not be determined.