Expanded Prospective Payment System and Use of and Outcomes with Home Dialysis by Race and Ethnicity in the United States

BACKGROUND AND OBJECTIVES

We investigated whether the recent growth in home dialysis use was proportional among all racial/ethnic groups and also whether there were changes in racial/ethnic differences in home dialysis outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This observational cohort study of US Renal Data System patients initiating dialysis from 2005 to 2013 used logistic regression to estimate racial/ethnic differences in home dialysis initiation over time, and used competing risk models to assess temporal changes in racial/ethnic differences in home dialysis outcomes, specifically: (1) transfer to in-center hemodialysis (HD), (2) mortality, and (3) transplantation.

RESULTS

Of the 523,526 patients initiating dialysis from 2005 to 2013, 55% were white, 28% black, 13% Hispanic, and 4% Asian. In the earliest era (2005-2007), 8.0% of white patients initiated dialysis with home modalities, as did a similar proportion of Asians (9.2%; adjusted odds ratio [aOR], 0.95; 95% confidence interval [95% CI], 0.86 to 1.05), whereas lower proportions of black [5.2%; aOR, 0.71; 95% CI, 0.66 to 0.76] and Hispanic (5.7%; aOR, 0.83; 95% CI, 0.86 to 0.93) patients did so. Over time, home dialysis use increased in all groups and racial/ethnic differences decreased (2011-2013: 10.6% of whites, 8.3% of blacks [aOR, 0.81; 95% CI, 0.77 to 0.85], 9.6% of Hispanics [aOR, 0.94; 95% CI, 0.86 to 1.00], 14.2% of Asians [aOR, 1.04; 95% CI, 0.86 to 1.12]). Compared with white patients, the risk of transferring to in-center HD was higher in blacks, similar in Hispanics, and lower in Asians; these differences remained stable over time. The mortality rate was lower for minority patients than for white patients; this difference increased over time. Transplantation rates were lower for blacks and similar for Hispanics and Asians; over time, the difference in transplantation rates between blacks and Hispanics versus whites increased.

CONCLUSIONS

From 2005 to 2013, as home dialysis use increased, racial/ethnic differences in initiating home dialysis narrowed, without worsening rates of death or transfer to in-center HD in minority patients, as compared with white patients.

Renin-angiotensin system blockers and residual kidney function loss in patients initiating peritoneal dialysis: an observational cohort study

Background

Although angiotensin-converting enzyme inhibitors (ACEI) and angiotensin-II receptor blockers (ARB) have been shown to preserve residual kidney function in a select group of Asian patients undergoing continuous ambulatory peritoneal dialysis (PD) in two small randomized clinical trials, the effectiveness of these drugs has yet to be demonstrated in a more diverse population of patients with multiple comorbid conditions. We investigated the association between ACEI/ARB use and development of recorded anuria in a cohort of patients initiating PD in the U.S.

Methods

We conducted a retrospective observational cohort study using the US Renal Data System and electronic health records data from a large national dialysis provider. We identified adult patients who initiated PD from 2007 to 2011. Only patients who participated in the federal prescription drug benefit program, Medicare Part D, for the first 90 days of dialysis were included. Patients who filled a prescription for an ACEI or ARB during those 90 days were considered users. We applied Cox proportional hazards models to an inverse probability of treatment-weighted (IPTW) cohort to estimate the hazard ratio (HR) for anuria (24-h urine volume < 200 ml) in ACEI/ARB users vs. non-users.

Results

Among 886 patients, 389 (44%) used an ACEI/ARB. Almost a third of these patients were black or Hispanic, and more than a quarter had comorbidities that would have excluded them from the randomized clinical trials of ACEI/ARB. Two hundred eighty patients reached anuria over 840 person-years of follow-up, for a composite event rate of 33 events per 100 person-years. We found no clear association between ACEI/ARB use and progression to anuria [HR: 0.86, 95% CI: 0.73–1.02].

Conclusions

ACEI/ARB use is common in patients initiating PD in the U.S. but was not associated with a lower risk of anuria. Residual confounding by unmeasured variables is an important limitation of this observational study. Still, these findings suggest that pragmatic clinical trials are warranted to test the effectiveness of ACEI/ARB in slowing the decline of residual kidney function in a diverse population of peritoneal dialysis patients with multiple comorbid conditions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0616-4) contains supplementary material, which is available to authorized users.

Angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use and cardiovascular outcomes in patients initiating peritoneal dialysis

Background

Data on the effectiveness of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) in reducing cardiovascular (CV) risk in patients undergoing peritoneal dialysis (PD) are limited. We investigated the association between ACEI/ARB use and CV outcomes in patients initiating PD.

Methods

In this observational cohort study, we identified from the United States Renal Data System all adult patients who initiated PD from 2007 to 2011 and participated in Medicare Part D, a federal prescription drug benefits program, for the first 90 days of dialysis. Patients who filled a prescription for an ACEI or ARB in those 90 days were considered users. We applied Cox regression to an inverse probability of treatment weighted cohort to estimate the hazard ratios (HRs) for the combined outcome of death, ischemic stroke or myocardial infarction (MI) and each outcome individually.

Results

Among 4879 patients, 2063 (42%) used an ACEI/ARB. Patients were followed up for a median of 1.2 years. We recorded 1771 events, for a composite rate of 25 events per 100 person-years. ACEI/ARB use (versus nonuse) was associated with a reduced risk of the composite outcome {HR 0.84 [95% confidence interval (CI) 0.76-0.93]}, all-cause mortality [HR 0.83 (95% CI 0.75-0.92)] and CV death [HR 0.74 (95% CI 0.63-0.87)], but not MI [HR 0.88 (95% CI 0.69-1.12)] or ischemic stroke [HR 1.06 (95% CI 0.79-1.43)]. Results were similar in as-treated analyses. In a subgroup analysis, we did not find any effect modification by residual renal function.

Conclusions

ACEI/ARB use is common in patients initiating PD and is associated with a lower risk of fatal CV outcomes.

Comparative effectiveness of angiotensin receptor blockers vs. angiotensin-converting enzyme inhibitors on cardiovascular outcomes in patients initiating peritoneal dialysis

BACKGROUND

There is evidence that angiotensin-converting enzyme inhibitors (ACEI) and angiotensin-II receptor blockers (ARB) may reduce cardiovascular (CV) risk in patients undergoing peritoneal dialysis (PD), but no studies have compared the effectiveness between these drug classes. In this observational cohort study, we compared the association of ARB vs. ACEI use on CV outcomes in patients initiating PD.

METHODS

We identified from the US Renal Data System all adult patients who initiated PD from 2007 to 2011 and participated in Medicare Part D, a federal prescription drug benefits program, for the first 90 days of dialysis. Patients who filled a prescription for an ACEI or ARB in those 90 days were considered users. We excluded patients who used both ACEI and ARB. We applied Cox proportional hazards regression to an inverse probability of treatment-weighted cohort to estimate the hazard ratios (HR) for the combined outcome of all-cause death, ischemic stroke, or myocardial infarction; all-cause mortality; and CV death.

RESULTS

Among 1892 patients using either drug class, 39 % were ARB users. We observed 624 events over 2,898 person-years of follow-up, for a composite event rate of 22 events per 100 person-years. We observed no differences between ARB vs. ACEI users: composite outcome HR 0.94, 95 % confidence interval (CI) 0.79-1.11; all-cause mortality HR 0.92, 95 % CI 0.76-1.10; CV death HR: 1.06, 95 % CI 0.80-1.41.

CONCLUSION

We identified no significant difference in the risks of CV events or death between users of ARBs vs. ACEIs in patients initiating PD, thus supporting their mostly interchangeable use in this population.

Recent advances in the management of peritoneal dialysis patients

Peritoneal dialysis is a form of kidney dialysis that is used to remove accumulated metabolic waste products and water in patients with end stage kidney disease. Long-term exposure to high concentrations of glucose and its by-products, both found in peritoneal dialysis fluid, has been implicated in contributing to peritoneal damage over time, in turn limiting long-term use of the technique. Newer peritoneal dialysis solutions have been developed in the hope of reducing the unfavorable effects of peritoneal dialysis solutions. In vitro and in vivo studies have suggested that newer peritoneal dialysis fluids have salutary effects on the peritoneal membrane. Short-term clinical studies have also found some metabolic benefits of glucose-sparing regimens in chronic peritoneal dialysis. Mixed results have been found in studies examining whether newer peritoneal dialysis fluids reduce peritonitis rates. Long-term studies are needed to investigate whether newer peritoneal dialysis fluids provide better peritoneal dialysis technique and/or patient survival, compared to standard glucose-based peritoneal dialysis fluids.

Prevalence and correlates of functional dependence among maintenance dialysis patients

Functional dependence is an important determinant of longevity and quality of life. The purpose of the current study was to determine the prevalence and correlates of functional dependence among patients with end-stage renal disease (ESRD) receiving maintenance dialysis. We enrolled 148 participants with ESRD from five clinics. Functional status, as measured by basic and instrumental activities of daily living (ADL, IADL), was ascertained by validated questionnaires. Functional dependence was defined as needing assistance in at least one of seven IADLs or at least one of four ADLs. Demographic characteristics, chronic health conditions, anthropometric measurements, and laboratories were assessed by a combination of self-report and chart review. Cognitive function was assessed with a neurocognitive battery, and depressive symptoms were assessed by questionnaire. Mean age of the sample was 56.2 ± 14.6 years. Eighty-seven participants (58.8%) demonstrated dependence in ADLs or IADLs, 70 (47.2%) exhibited IADL dependence alone, and 17 (11.5%) exhibited combined IADL and ADL dependence. In a multivariable-adjusted model, stroke, cognitive impairment, and higher systolic blood pressure were independent correlates of functional dependence. We found no significant association between demographic characteristics, chronic health conditions, depressive symptoms or laboratory measurements, and functional dependence. Impairment in executive function was more strongly associated with functional dependence than memory impairment. Functional dependence is common among ESRD patients and independently associated with stroke, systolic blood pressure, and executive function impairment.

Urgent-start peritoneal dialysis: a chance for a new beginning

Peritoneal dialysis (PD) remains greatly underutilized in the United States despite the widespread preference of home modalities among nephrologists and patients. A hemodialysis-centric model of end-stage renal disease care has perpetuated for decades due to a complex set of factors, including late end-stage renal disease referrals and patients who present to the hospital requiring urgent renal replacement therapy. In such situations, PD rarely is a consideration and patients are dialyzed through a central venous catheter, a practice associated with high infection and mortality rates. Recently, the term urgent-start PD has gained momentum across the nephrology community and has begun to change this status quo. It allows for expedited placement of a PD catheter and initiation of PD therapy within days. Several published case reports, abstracts, and poster presentations at national meetings have documented the initial success of urgent-start PD programs. From a wide experiential base, we discuss the multifaceted issues related to urgent-start PD implementation, methods to overcome barriers to therapy, and the potential impact of this technique to change the existing dialysis paradigm.

Determinants of peritoneal dialysis technique failure in incident US patients

OBJECTIVES

Switching from peritoneal dialysis (PD) to hemodialysis (HD) is undesirable, because of complications from temporary vascular access, disruption of daily routine, and higher costs. Little is known about the role that social factors play in technique failure.

DESIGN, SETTING, PARTICIPANTS, MEASUREMENTS

We followed for 3 years a nationally representative cohort of US patients who initiated PD in 1996 - 1997. Technique failure was defined as any switch from PD to HD for 30 days or more. We used Cox regression to examine associations between technique failure and demographic, medical, social, and pre-dialysis factors. We estimated hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

We identified an inception cohort of 1587 patients undergoing PD. In multivariate analysis, female sex (HR: 0.78; 95% CI: 0.64 to 0.95) was associated with lower rates of technique failure, and black race [compared with white race (HR: 1.48; 95% CI: 1.20 to 1.82)] and receiving Medicaid (HR: 1.48; 95% CI: 1.17 to 1.86) were associated with higher rates. Compared with patients who worked full-time, those who were retired (HR: 1.49; 95% CI: 1.07 to 2.08) or disabled (HR: 1.38; 95% CI: 1.01 to 1.88) had higher rates of failure. Patients with a systolic blood pressure of 140 - 160 mmHg had a higher rate of failure than did those with a pressure of 120 - 140 mmHg (HR: 1.24; 95% CI: 1.00 to 1.52). Earlier referral to a nephrologist (>3 months before dialysis initiation) and the primary decision-maker for the dialysis modality (physician vs patient vs shared) were not associated with technique failure.

CONCLUSIONS

This study confirms that several socio-demographic factors are associated with technique failure, emphasizing the potential importance of social and financial support in maintaining PD.

Prevalence and significance of stroke symptoms among patients receiving maintenance dialysis

OBJECTIVE

The purpose of this cross-sectional study was to determine the prevalence and potential significance of stroke symptoms among end-stage renal disease (ESRD) patients without a prior diagnosis of stroke or TIA.

METHODS

We enrolled 148 participants with ESRD from 5 clinics. Stroke symptoms and functional status, basic and instrumental activities of daily living (ADL, IADL), were ascertained by validated questionnaires. Cognitive function was assessed with a neurocognitive battery. Cognitive impairment was defined as a score 2 SDs below norms for age and education in 2 domains. IADL impairment was defined as needing assistance in at least 1 of 7 IADLs.

RESULTS

Among the 126 participants without a prior stroke or TIA, 46 (36.5%) had experienced one or more stroke symptoms. After adjustment for age, sex, race, education, language, diabetes, and cardiovascular disease, participants with stroke symptoms had lower scores on tests of attention, psychomotor speed, and executive function, and more pronounced dependence in IADLs and ADLs (p ≤ 0.01 for all). After adjustment for age, sex, race, education, language, diabetes, and cardiovascular disease, participants with stroke symptoms had a higher likelihood of cognitive impairment (odds ratio [OR] 2.47, 95% confidence interval [CI] 1.03-5.92) and IADL impairment (OR 3.86, 95% CI 1.60-9.28).

CONCLUSIONS

Stroke symptoms are common among patients with ESRD and strongly associated with impairments in cognition and functional status. These findings suggest that clinically significant stroke events may go undiagnosed in this high-risk population.

Systematic barriers to the effective delivery of home dialysis in the United States: a report from the Public Policy/Advocacy Committee of the North American Chapter of the International Society for Peritoneal Dialysis

Home dialysis, currently underused in the United States compared with other industrialized countries, likely will benefit from the newly implemented US prospective payment system. Not only is home dialysis less expensive from the standpoint of pure dialysis costs, but overall health system costs may be decreased by more subtle benefits, such as reduced transportation. However, many systematic barriers exist to the successful delivery of home dialysis. We organized these barriers into the categories of educational barriers (patient and providers), governmental/regulatory barriers (state and federal), and barriers specifically related to the philosophies and business practices of dialysis providers (eg, staffing, pharmacies, supplies, space, continuous quality improvement practices, and independence). All stakeholders share the goal of delivering home dialysis therapies in the most cost- and clinically effective and least problematic manner. Identification and recognition of such barriers is the first step. In addition, we have suggested action plans to stimulate the kidney community to find even better solutions so that collectively we may overcome these barriers.

Preoperative renal volumes as a predictor of graft function in living donor transplantation

BACKGROUND

Nephron underdosing and donor kidney-recipient body size mismatch can lead to poor allograft function. The purpose of this study is to examine the relationship between donor kidney volume and posttransplantation graft function by using magnetic resonance imaging (MRI) to obtain renal volumes. Previous investigators used donor body surface area as a surrogate for kidney size or measured renal volume by using ultrasonography; both these techniques are inaccurate measures of renal volume. Intraoperative weights are more accurate, but provide information only after the transplantation is underway. More recently, MRI has been used preoperatively to screen living donors; these novel MRI techniques also provide information regarding renal size.

METHODS

We performed a retrospective analysis of 54 patients who underwent living donor transplantation at our institution from 2000 to 2002. All living donors underwent preoperative renovascular imaging using MRI, and renal volumes were obtained for each donor. A transplant kidney volume-recipient body weight (Vol/Wt) ratio was determined for each donor-recipient pair, and patients were divided into tertiles corresponding to 3 groups: high (>2.7), medium (2 to 2.7), and low (<2) "nephron dose" ratios.

RESULTS

Glomerular filtration rate (GFR) correlated with Vol/Wt ratio at 6 and 12 months (r = 0.46; P = 0.0005 and r = 0.41; P = 0.003). At 6 months, mean GFRs in the low, medium, and high groups were 52.4 +/- 2.8 (SEM), 64.5 +/- 6.2, and 82.0 +/- 4.4 mL/min, respectively (P < 0.0005). At 12 months, GFRs in the low, medium, and high groups were 51.6 +/- 3.6, 63.3 +/- 3.8, and 83.9 +/- 5.4 mL/min, respectively (P < 0.0001).

CONCLUSION

Transplantation of donor-recipient pairs with a Vol/Wt ratio less than 2 cm 3 /kg was associated with significantly worse graft function. Donor kidney volumes measured by means of preoperative MRI can be used to calculate Vol/Wt ratios before transplantation and identify patients at risk for a low GFR posttransplantation.

Preoperative renal volumes as a predictor of graft function in living donor transplantation

BACKGROUND

Nephron underdosing and donor kidney-recipient body size mismatch can lead to poor allograft function. The purpose of this study is to examine the relationship between donor kidney volume and posttransplantation graft function by using magnetic resonance imaging (MRI) to obtain renal volumes. Previous investigators used donor body surface area as a surrogate for kidney size or measured renal volume by using ultrasonography; both these techniques are inaccurate measures of renal volume. Intraoperative weights are more accurate, but provide information only after the transplantation is underway. More recently, MRI has been used preoperatively to screen living donors; these novel MRI techniques also provide information regarding renal size.

METHODS

We performed a retrospective analysis of 54 patients who underwent living donor transplantation at our institution from 2000 to 2002. All living donors underwent preoperative renovascular imaging using MRI, and renal volumes were obtained for each donor. A transplant kidney volume-recipient body weight (Vol/Wt) ratio was determined for each donor-recipient pair, and patients were divided into tertiles corresponding to 3 groups: high (>2.7), medium (2 to 2.7), and low (<2) "nephron dose" ratios.

RESULTS

Glomerular filtration rate (GFR) correlated with Vol/Wt ratio at 6 and 12 months (r = 0.46; P = 0.0005 and r = 0.41; P = 0.003). At 6 months, mean GFRs in the low, medium, and high groups were 52.4 +/- 2.8 (SEM), 64.5 +/- 6.2, and 82.0 +/- 4.4 mL/min, respectively (P < 0.0005). At 12 months, GFRs in the low, medium, and high groups were 51.6 +/- 3.6, 63.3 +/- 3.8, and 83.9 +/- 5.4 mL/min, respectively (P < 0.0001).

CONCLUSION

Transplantation of donor-recipient pairs with a Vol/Wt ratio less than 2 cm 3 /kg was associated with significantly worse graft function. Donor kidney volumes measured by means of preoperative MRI can be used to calculate Vol/Wt ratios before transplantation and identify patients at risk for a low GFR posttransplantation.