Agreement of reported vascular access on the medical evidence report and on medicare claims at hemodialysis initiation

Racial Disparities in the Arteriovenous Fistula Care Continuum in Hemodialysis Patients

BACKGROUND AND OBJECTIVES

Arteriovenous fistulas are the optimal vascular access type for patients on hemodialysis. However, arteriovenous fistulas are used less frequently in Black than in White individuals. The arteriovenous fistula care continuum comprises a series of sequential steps. A better understanding is needed of where disparities exist along the continuum in order to mitigate racial differences in arteriovenous fistula use.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using Medicare claims data from the United States Renal Data System, longitudinal analyses of patients ≥67 years initiating hemodialysis with a central venous catheter between July 1, 2010 and June 30, 2012 were performed. Three patient cohorts were identified: patients initiating hemodialysis with a catheter (n=41,814), patients with arteriovenous fistula placement within 6 months of dialysis initiation (n=14,077), and patients whose arteriovenous fistulas were successfully used within 6 months of placement (n=7068). Three arteriovenous fistula processes of care outcomes were compared between Blacks and Whites: (1) arteriovenous fistula creation, (2) successful arteriovenous fistula use, and (3) primary arteriovenous fistula patency after successful use.

RESULTS

An arteriovenous fistula was placed within 6 months of dialysis initiation in 37% of patients initiating dialysis with a catheter. Among the patients with arteriovenous fistula placement, the arteriovenous fistula was successfully used for dialysis within 6 months in 48% of patients. Among patients with successful arteriovenous fistula use, 21% maintained primary arteriovenous fistula patency at 3 years. After adjusting for competing risks, Black patients on hemodialysis were 10% less likely to undergo arteriovenous fistula placement (adjusted subdistribution hazard ratio, 0.90; 95% confidence interval, 0.87 to 0.94); 12% less likely to have successful arteriovenous fistula use after placement (adjusted subdistribution hazard ratio, 0.88; 95% confidence interval, 0.83 to 0.93); and 22% less likely to maintain primary arteriovenous fistula patency after successful use (subdistribution hazard ratio, 0.78; 95% confidence interval, 0.74 to 0.84).

CONCLUSIONS

Lower arteriovenous fistula use among Blacks older than 67 years of age treated with hemodialysis was attributable to each step along the continuum of arteriovenous fistula processes of care.

Vascular Access and Risk of Bloodstream Infection Among Older Incident Hemodialysis Patients

Rationale & Objective

Most new patients with end-stage renal disease (ESRD) initiate hemodialysis (HD) with a central venous catheter (CVC) and later transition to a permanent vascular access with lower infection risk. The benefit of early fistula use in preventing severe infections is incompletely understood. We examined patients' first access and subsequent transitions between accesses during the first year of HD to estimate the risk for bloodstream infection (BSI) associated with incident and time-dependent use of HD access.

Study Design

A retrospective cohort study using enhanced 5% Medicare claims data.

Setting & Participants

New patients with ESRD initiating HD between January 1, 2011, and December 31, 2012, and having complete pre-ESRD Medicare fee-for-service coverage for 2 years.

Exposure

The incident and prevalent use of CVC, graft, or fistula as determined from monthly reports to the Centers for Medicare & Medicaid Services by HD providers.

Outcome

Incident hospitalization with a primary/secondary diagnosis of BSI (International Classification of Diseases, Ninth Revision, Clinical Modification code 038.xx or 790.7).

Analytical Approach

Extended survival analysis accounting for patient confounders.

Results

Of 2,352 study participants, 1,870 (79.5%), 77 (3.3%), and 405 (17.2%) initiated HD with a CVC, graft, and fistula, respectively. During the first year, the incident BSI hospitalization rates per 1,000 person-days were 1.3, 0.8, and 0.3 (P<0.001) in patients initiating with a CVC, graft, and fistula, respectively. After adjusting for confounders, incident fistula use was associated with 61% lower risk for BSI (HR, 0.39; 95% CI, 0.28-0.54; P<0.001) compared with incident CVC or graft use. The prevalent fistula or graft use was associated with lower risk for BSI compared with prevalent CVC use (HRs of 0.30 [95% CI, 0.22-0.42] and 0.47 [95% CI, 0.31-0.73], respectively).

Limitations

Restricted to an elderly population; potential residual confounding.

Conclusions

Incident fistula use was associated with lowest rates of BSI, but the majority of beneficiaries with pre-ESRD insurance initiated HD with a CVC. Strategies are needed to improve pre-ESRD fistula placement.

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.

Evaluation of upper limb superficial venous percussion as a sign of anatomical location and venous permeability. A comparative study of superficial venous percussion to ultrasound findings on non-renal patients and on chronic kidney disease patients

METHODS

An analytical cross-sectional study with 70 individuals divided into two groups. Group A consisted of 35 volunteers who were being preoperatively prepared for the construction of arteriovenous fistula. Group B consisted of 35 non-renal patients selected by convenience. Each participant underwent physical examination, including venous percussion, of the dominant upper limb and then ultrasound. Interobserver agreement was assessed between a trained vascular surgeon performing percussion and fourth-year medical student. Accuracy, sensitivity, specificity, positive predictive value and negative predictive value of percussion were determined in relation to ultrasound. The agreement between the methods, venous percussion and venous duplex ultrasound was also evaluated by the Kappa index.

RESULTS

The overall interobserver agreement for the percussion was 0.74 (95% CI 0.632 to 0.851). It was observed that the results were more favorable in the cephalic vein than in the basilic vein, emphasizing that the cephalic is more used in venous punctures, because of its anatomical location and visibility, and in fistula construction. The 35 percussions of the cephalic forearm vein in Group A resulted in a sensitivity of 1.0 (95% CI 0.63 to 1.00), specificity of 0.96 (95% CI 0.81 to 1.00), a positive predictive value of 0.89(95% CI 0.52 to 1.00) and a negative predictive value of 1.00 (95% CI 0.87 to 1.00), with an accuracy of 0.97 (95% CI 0.85 to 1.00) and Kappa index of 0.92 (95% CI 0.77 to 1.00) in relation to ultrasound. Overall, when all venous segments were analyzed in group A, the Kappa index of agreement between the percussion and the ultrasonography reached 0.56 (95% CI 0.401 to 0.72). All venous segments in Group A had a sensitivity of 0.54 (95% CI 0.37 to 0.70) and a specificity of 0.96 (95% CI 0.90 to 0.99). When all venous segments were analyzed in group B, the Kappa index of agreement between the percussion and the ultrasonography reached 0.48 (95% CI 0.34 to 0.62). All venous segments in Group B had a sensitivity of 0.70 (95% CI 0.59 to 0.79) and a specificity of 0.82 (95% CI 0.69 to 0.91).

CONCLUSION

Venous percussion of the upper limbs has a high positive predictive value and high specificity, when compared to ultrasound as a way to evaluate the patency and adequacy of the cephalic vein. Although there is not enough evidence to preclude ultrasound, percussion should definitely be included in the traditional physical exam evaluation of upper limbs superficial veins.

Infrainguinal bypass surgery outcomes are worse in hemodialysis patients compared with patients with renal transplants

OBJECTIVE

Studies of infrainguinal bypass surgery (IBS) in patients with end-stage renal disease have focused on hemodialysis (HD) patients. Little is known of the applicability of their outcomes to patients with renal transplants (RTs). In this study, we sought to compare perioperative and long-term outcomes of IBS in a large population-based cohort of HD and RT patients.

METHODS

A retrospective review of all HD and RT patients who underwent IBS between January 2007 and December 2011 in the U.S. Renal Data System was performed. Univariable, Kaplan-Meier, multivariable logistic, and Cox regression analyses were employed to evaluate 30-day postoperative (graft failure, limb loss, conduit infection, death) and long-term (primary patency [PP], primary assisted patency [PAP], secondary patency [SP], limb salvage, mortality) outcomes.

RESULTS

There were 10,787 IBSs performed in 9739 (90%) HD patients and 1048 (10%) RT patients who presented predominantly with critical limb ischemia (72%). Bypass configurations were femoral-popliteal (48%), femoral-tibial (34%), and popliteal-tibial (18%). Comparing HD vs RT patients, PP, PAP, and SP were 18% vs 33%, 23% vs 38%, and 30% vs 48%, respectively, at 5 years among autogenous conduit recipients (all P < .001) and 20% vs 28% (P = .02), 23% vs 31% (P = .02), and 33% vs 53% (P < .001) among prosthetic conduit recipients. Limb salvage and patient survival were 39% vs 56% and 19% vs 48%, respectively, at 5 years (all P < .001). Risk-adjusted analyses demonstrated higher PP (adjusted hazard ratio [aHR], 1.32; 95% confidence interval [CI], 1.20-1.45; P < .001), PAP (aHR, 1.32; 95% CI, 1.19-1.45; P < .001), SP (aHR, 1.47; 95% CI, 1.31-1.65; P < .001), limb salvage (aHR, 1.48; 95% CI, 1.30-1.67; P < .001), and patient survival (aHR, 2.42; 95% CI, 2.17-2.71; P < .001) for RT compared with HD patients.

CONCLUSIONS

The HD-dependent state is associated with elevated bypass and patient-level risks after IBS compared with patients with RTs. These results show that the benefits of renal transplantation likely extend to infrainguinal bypass-specific outcomes. The estimates of risk reported herein should inform the patient's and provider's expectations at the point of care.

Association of Medicaid Expansion With 1-Year Mortality Among Patients With End-Stage Renal Disease

IMPORTANCE

The Affordable Care Act Medicaid expansion may be associated with reduced mortality, but evidence to date is limited. Patients with end-stage renal disease (ESRD) are a high-risk group that may be particularly affected by Medicaid expansion.

OBJECTIVE

To examine the association of Medicaid expansion with 1-year mortality among nonelderly patients with ESRD initiating dialysis.

DESIGN, SETTING, AND PARTICIPANTS

Difference-in-differences analysis of nonelderly patients initiating dialysis in Medicaid expansion and nonexpansion states from January 2011 to March 2017.

EXPOSURE

Living in a Medicaid expansion state.

MAIN OUTCOMES AND MEASURES

The primary outcome was 1-year mortality. Secondary outcomes were insurance, predialysis nephrology care, and type of vascular access for hemodialysis.

RESULTS

A total of 142 724 patients in expansion states (mean age, 50.2 years; 40.2% women) and 93 522 patients in nonexpansion states (mean age, 49.7; 42.4% women) were included. In Medicaid expansion states, 1-year mortality following dialysis initiation declined from 6.9% in the preexpansion period to 6.1% after expansion (change, -0.8 percentage points; 95% CI, -1.1 to -0.5). In nonexpansion states, mortality rates were 7.0% before expansion and 6.8% after expansion (change, -0.2 percentage points; 95% CI, -0.5 to 0.2), yielding an adjusted absolute reduction in mortality in expansion states of -0.6 percentage points (95% CI, -1.0 to -0.2). Mortality reductions were largest for black patients (-1.4 percentage points; 95% CI, -2.2, -0.7; P=.04 for interaction) and patients aged 19 to 44 years (-1.1 percentage points; 95% CI, -2.1 to -0.3; P=.01 for interaction). Expansion was associated with a 10.5-percentage-point (95% CI, 7.7-13.2) increase in Medicaid coverage at dialysis initiation, a -4.2-percentage-point (95% CI, -6.0 to -2.3) decrease in being uninsured, and a 2.3-percentage-point (95% CI, 0.6-4.1) increase in the presence of an arteriovenous fistula or graft. Changes in predialysis nephrology care were not significant.

CONCLUSIONS AND RELEVANCE

Among patients with ESRD initiating dialysis, living in a state that expanded Medicaid under the Affordable Care Act was associated with lower 1-year mortality. If this association is causal, further research is needed to understand what factors may have contributed to this finding.

Data concordance between ESRD Medical Evidence Report and Medicare claims: is there any improvement?

BACKGROUND

Medicare is one of the world's largest health insurance programs. It provides health insurance to nearly 44 million beneficiaries whose entitlements are based on age, disability, or end-stage renal disease (ESRD). Data of these ESRD beneficiaries are collected in the US Renal Data System (USRDS), which includes comorbidity information entered at the time of dialysis initiation (medical evidence data), and are used to shape health care policy. One limitation of USRDS data is the lack of validation of these medical evidence comorbidities against other comorbidity data sources, such as medical claims data.

METHODS

We examined the potential for discordance between USRDS Medical Evidence and medical claims data for 11 comorbid conditions amongst Medicare beneficiaries in 2011-2013 via sensitivity, specificity, kappa and hierarchical logistic regression.

RESULTS

Among 61,280 patients, most comorbid conditions recorded on the Medical Evidence forms showed high specificity (>0.9), compared to prior medical claims as reference standard. However, both sensitivity and kappa statistics varied greatly and tended to be low (most <0.5). Only diabetes appeared accurate, whereas tobacco use and drug dependence showed the poorest quality (sensitivity and kappa <0.1). Institutionalization and patient region of residency were associated with data discordance for six and five comorbidities out of 11, respectively, after conservative adjustment of multiple testing. Discordance appeared to be non-informative for congestive heart failure but was most varied for drug dependence.

CONCLUSIONS

We conclude that there is no improvement in comorbidity data quality in incident ESRD patients over the last two decades. Since these data are used in case-mix adjustment for outcome and quality of care metrics, the findings in this study should press regulators to implement measures to improve the accuracy of comorbidity data collection.

Tradeoffs in Vascular Access Selection in Elderly Patients Initiating Hemodialysis With a Catheter

RATIONALE & OBJECTIVE

National vascular access guidelines recommend placement of arteriovenous fistulas (AVFs) over grafts (AVGs) in hemodialysis patients, but have not been comprehensively assessed in the elderly. We evaluated clinically relevant vascular access outcomes in elderly patients receiving an AVF or AVG after hemodialysis therapy initiation.

STUDY DESIGN

Retrospective cohort study using national administrative data.

SETTINGS & PARTCIPANTS

Claims data from the US Renal Data System of 9,458 US patients 67 years and older who initiated hemodialysis therapy from July 1, 2010, to June 30, 2011, with a catheter and received an AVF (n=7,433) or AVG (n=2,025) within the ensuing 6 months.

PREDICTOR

Arteriovenous access subtype, AVF or AVG.

OUTCOMES

Successful use of vascular access, interventions to make vascular access functional, duration of catheter dependence before successful use of vascular access, frequency of interventions, and abandonment after successful use of vascular access.

ANALYTICAL APPROACH

Multivariable logistic regression analysis was used to compare the need for intervention before successful use of AVFs and AVGs, and negative bionomial regression was used to calculate the frequency of intervention after successful use of vascular access.

RESULTS

Unsuccessful use of vascular access within 6 months of creation was higher for AVFs versus AVGs (51% vs 45%; adjusted HR, 1.86; 95% CI, 1.73-1.99). Interventions to make vascular access functional were greater in AVFs versus AVGs (42% vs 23%; OR, 2.66; 95% CI, 2.26-3.12). AVFs had a lower 1-year abandonment rate after successful use compared with AVGs (OR, 0.71; 95% CI, 0.62-0.83) and required one-fourth fewer interventions after successful use (relative risk, 0.75; 95% CI, 0.69-0.81). Patients receiving an AVF had substantially longer catheter dependence before successful use than those receiving an AVG (median time, 3 vs 1 month; P<0.001).

LIMITATIONS

Residual confounding due to vascular access choice, restriction to an elderly population, and 1-year follow-up period.

CONCLUSIONS

In elderly hemodialysis patients initiating hemodialysis therapy with a catheter, the optimal vascular access selection depends on tradeoffs between shorter catheter dependence and less frequent interventions to make the vascular access (AVG) functional versus longer access patency and fewer interventions after successful use of the vascular access (AVF).

Medicare Costs Associated With Arteriovenous Fistulas Among US Hemodialysis Patients

BACKGROUND

An arteriovenous fistula (AVF) is the recommended vascular access for hemodialysis (HD). Previous studies have not examined the resources and costs associated with creating and maintaining AVFs.

STUDY DESIGN

Retrospective observational study.

SETTING & PARTICIPANTS

Elderly US Medicare patients initiating hemodialysis therapy during 2010 to 2011.

PREDICTOR

AVF primary and secondary patency and nonuse in the first year following AVF creation.

OUTCOMES

Annualized vascular access costs per patient per year.

RESULTS

Among patients with only a catheter at HD therapy initiation, only 54% of AVFs were successfully used for HD, 10% were used but experienced secondary patency loss within 1 year of creation, and 83% experienced primary patency loss within 1 year of creation. Mean vascular access costs per patient per year in the 2.5 years after AVF creation were $7,871 for AVFs that maintained primary patency in year 1, $13,282 for AVFs that experienced primary patency loss in year 1, $17,808 for AVFs that experienced secondary patency loss in year 1, and $31,630 for AVFs that were not used. Similar patterns were seen among patients with a mature AVF at HD therapy initiation and patients with a catheter and maturing AVF at HD therapy initiation. Overall, in 2013, fee-for-service Medicare paid $2.8 billion for dialysis vascular access-related services, ∼12% of all end-stage renal disease payments.

LIMITATIONS

Lack of granularity with certain billing codes.

CONCLUSIONS

AVF failure in the first year after creation is common and results in substantially higher health care costs. Compared with patients whose AVFs maintained primary patency, vascular access costs were 2 to 3 times higher for patients whose AVFs experienced primary or secondary patency loss and 4 times higher for patients who never used their AVFs. There is a need to improve AVF outcomes and reduce costs after AVF creation.

Validity of administrative database code algorithms to identify vascular access placement, surgical revisions, and secondary patency

BACKGROUND:

We assessed the validity of physician billing codes and hospital admission using International Classification of Diseases 10th revision codes to identify vascular access placement, secondary patency, and surgical revisions in administrative data.

METHODS:

We included adults (≥18 years) with a vascular access placed between 1 April 2004 and 31 March 2013 at the University Health Network, Toronto. Our reference standard was a prospective vascular access database (VASPRO) that contains information on vascular access type and dates of placement, dates for failure, and any revisions. We used VASPRO to assess the validity of different administrative coding algorithms by calculating the sensitivity, specificity, and positive predictive values of vascular access events.

RESULTS:

The sensitivity (95% confidence interval) of the best performing algorithm to identify arteriovenous access placement was 86% (83%, 89%) and specificity was 92% (89%, 93%). The corresponding numbers to identify catheter insertion were 84% (82%, 86%) and 84% (80%, 87%), respectively. The sensitivity of the best performing coding algorithm to identify arteriovenous access surgical revisions was 81% (67%, 90%) and specificity was 89% (87%, 90%). The algorithm capturing arteriovenous access placement and catheter insertion had a positive predictive value greater than 90% and arteriovenous access surgical revisions had a positive predictive value of 20%. The duration of arteriovenous access secondary patency was on average 578 (553, 603) days in VASPRO and 555 (530, 580) days in administrative databases.

CONCLUSION:

Administrative data algorithms have fair to good operating characteristics to identify vascular access placement and arteriovenous access secondary patency. Low positive predictive values for surgical revisions algorithm suggest that administrative data should only be used to rule out the occurrence of an event.

Vascular Access Type and Clinical Outcomes among Elderly Patients on Hemodialysis

BACKGROUND AND OBJECTIVES

The optimal type of initial permanent access for hemodialysis among the elderly is controversial. Duration of central venous catheter dependence, patient comorbidities, and life expectancy are important considerations in whether to place an arteriovenous fistula or graft. We used an observational study design to compare clinical outcomes in elderly patients who initiated hemodialysis with a central venous catheter and subsequently had an arteriovenous fistula or graft placed.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We identified 9458 United States patients ages ≥67 years old who initiated hemodialysis from July 1, 2010 to June 30, 2011 with a central venous catheter and no secondary vascular access and then received an arteriovenous fistula (n=7433) or graft (n=2025) within 6 months. We evaluated key clinical outcomes during the 6 months after vascular access placement coincident with high rates of catheter use and used a matched propensity score analysis to examine patient survival.

RESULTS

Central venous catheter dependence was greater in every month during the 6-month period after arteriovenous fistula versus graft placement (P<0.001). However, rates of all-cause infection-related hospitalization (adjusted relative risk, 0.93; 95% confidence interval, 0.87 to 0.99; P=0.01) and bacteremia/septicemia-related hospitalization (adjusted relative risk, 0.90; 95% confidence interval, 0.82 to 0.98; P=0.02) were lower in the arteriovenous fistula versus graft group as was the adjusted risk of death (hazard ratio, 0.76; 95% confidence interval, 0.73 to 0.80; P<0.001).

CONCLUSIONS

Despite extended central venous catheter dependence, elderly patients initiating hemodialysis with a central venous catheter who underwent arteriovenous fistula placement within 6 months had fewer hospitalizations due to infections and a lower likelihood of death than those receiving an arteriovenous graft.

Comparison of Post-Creation Procedures and Costs between Surgical and an Endovascular Approach to Arteriovenous Fistula Creation

Introduction

Due to early and late failures that may occur with surgically created hemodialysis arteriovenous fistulas (SAVF), post-creation procedures are commonly required to facilitate AVF maturation and maintain patency. This study compared AVF post-creation procedures and their associated costs in patients with SAVF to patients with a new endovascularly created AVF (endoAVF).

Methods

A 5% random sample from Medicare Standard Analytical Files was abstracted to determine post- creation procedures and associated costs for SAVF created from 2011 to 2013. Medicare enrollment during the 6 months prior to and after the AVF creation was required. Patients’ follow-up inpatient, outpatient, and physician claims were used to identify post-creation procedures and to estimate average procedure costs. Comparative procedural information on endoAVF was obtained from the Novel Endovascular Access Trial (NEAT).

Results

Of 3764 Medicare SAVF patients, 60 successfully matched to endoAVF patients using 1:1 propensity score matching of baseline demographic and clinical characteristics. The total post-creation procedural event rate within 1 year was lower for endoAVF patients (0.59 per patient-year) compared to the matched SAVF cohort (3.43 per patient-year; p<0.05). In the endoAVF cohort, event rates of angioplasty, thrombectomy, revision, catheter placement, subsequent arteriovenous graft (AVG), new SAVF, and vascular access-related infection were all significantly lower than in the SAVF cohort. The average first year cost per patient-year associated with post-creation procedures was estimated at US$11,240 USD lower for endoAVF than for SAVF.

Conclusions

Compared to patients with SAVF, patients with endoAVF required fewer post-creation procedures and had lower associated mean costs within the first year.

ESRD Databases, Public Policy, and Quality of Care: Translational Medicine and Nephrology

Efforts to improve care of patients with ESRD and the policies that guide those activities depend on evidence-based best practices derived from clinical trials and carefully conducted observational studies. Our review describes this process in the context of the translational research model (bench to bedside to populations), with a particular emphasis on bedside care. We illustrate some of its accomplishments and describe the limitations of the data and evidence supporting policy and practice.

The risk of bleeding with tunneled dialysis catheter placement

PURPOSE

The purpose of this study was to evaluate the risk of bleeding associated with tunneled dialysis catheter (TDC) placement in a large population of hemodialysis patients who were either anticoagulated or were taking antithrombotic medications.

METHODS

Medical records obtained over a two-year period were queried in order to select two groups of study cases. The first was a Med group (n = 458), cases which had a TDC placed while taking the antithrombotic medications (warfarin, clopidogrel or acetylsalicylic acid [ASA]) which were not discontinued or held. The second was a Declot Failure (DF) group (n = 941) and consisted of cases in which a TDC had been placed immediately following a failed arteriovenous access thrombectomy procedure in which they had been anticoagulated using unfractionated heparin. The results obtained in these two groups were compared to the incidence of bleeding observed in a cohort of 6555 TDC placements that had been performed previously referred to as the Control group.

RESULTS

The incidence of bleeding in the Control group was 0.46%. The incidence of bleeding in the DF group was 0.44% and in the Med group was 0.36%. No patient had bleeding that required transfusion, hospitalization, or catheter removal.

CONCLUSIONS

Based upon these data, it seems reasonable to classify the TDC placement procedure as having a very low risk of bleeding and to not require preprocedure laboratory testing. The value of suspending antithrombotic medications prior to TDC placement cannot be supported.

A comparison between physicians and computer algorithms for form CMS-2728 data reporting

INTRODUCTION

CMS-2728 form (Medical Evidence Report) assesses 23 comorbidities chosen to reflect poor outcomes and increased mortality risk. Previous studies questioned the validity of physician reporting on forms CMS-2728. We hypothesize that reporting of comorbidities by computer algorithms identifies more comorbidities than physician completion, and, therefore, is more reflective of underlying disease burden.

METHODS

We collected data from CMS-2728 forms for all 296 patients who had incident ESRD diagnosis and received chronic dialysis from 2005 through 2014 at Indiana University outpatient dialysis centers. We analyzed patients' data from electronic medical records systems that collated information from multiple health care sources. Previously utilized algorithms or natural language processing was used to extract data on 10 comorbidities for a period of up to 10 years prior to ESRD incidence. These algorithms incorporate billing codes, prescriptions, and other relevant elements. We compared the presence or unchecked status of these comorbidities on the forms to the presence or absence according to the algorithms.

FINDINGS

Computer algorithms had higher reporting of comorbidities compared to forms completion by physicians. This remained true when decreasing data span to one year and using only a single health center source. The algorithms determination was well accepted by a physician panel. Importantly, algorithms use significantly increased the expected deaths and lowered the standardized mortality ratios.

DISCUSSION

Using computer algorithms showed superior identification of comorbidities for form CMS-2728 and altered standardized mortality ratios. Adapting similar algorithms in available EMR systems may offer more thorough evaluation of comorbidities and improve quality reporting.

Differences in Initial Hemodialysis Vascular Access Use Among Glomerulonephritis Subtypes in the United States

BACKGROUND

The type of vascular access used for hemodialysis affects patient morbidity and mortality. Whether vascular access types differ by glomerulonephritis (GN) subtype in the US hemodialysis population has not been investigated.

STUDY DESIGN

Cross-sectional observational study.

SETTING & PARTICIPANTS

We identified all adult (aged ≥ 18 years) patients within the US Renal Data System who initiated hemodialysis therapy from July 2005 through December 2011 with a diagnosis of end-stage renal disease attributed to any of 4 primary (focal segmental glomerulosclerosis, immunoglobulin A nephropathy [reference group], membranous nephropathy, and membranoproliferative GN) or 2 secondary (lupus nephritis and vasculitis) GN subtypes.

PREDICTOR

GN subtype.

OUTCOMES

ORs with 95% CIs for arteriovenous fistula versus central venous catheter (CVC) use and for arteriovenous graft versus CVC use were computed using multinomial logistic regression, with adjustment for demographic, socioeconomic, comorbidity, and duration of nephrology care covariates.

RESULTS

Among 29,015 patients, CVC use at initiation of hemodialysis therapy was substantially higher in patients with lupus nephritis (89.2%) or vasculitis (91.2%) compared with patients with primary GN subtypes (72.7%-79.8%). After adjustment and compared with patients with immunoglobulin A nephropathy, patients with lupus nephritis or vasculitis were as likely to have used an arteriovenous graft (ORs of 0.94 [95% CI, 0.70-1.27] and 0.80 [95% CI, 0.56-1.13], respectively) but significantly less likely to have used an arteriovenous fistula (ORs of 0.66 [95% CI, 0.57-0.76] and 0.54 [95% CI, 0.45-0.63], respectively), whereas patients with any comparator primary GN subtype were at least as likely to have used either of these 2 access types.

LIMITATIONS

Potential misclassification of exposure; residual confounding by unmeasured covariates; inability to determine causes of observed associations; lacking longitudinal data for vascular access use.

CONCLUSIONS

Significant differences in vascular access distributions at initiation of hemodialysis therapy are apparent among GN subtypes. The unacceptably high use of CVCs in patients with lupus nephritis and vasculitis is particularly concerning. Further studies are needed to identify any potentially modifiable factors underlying these findings.

Outcomes of Elderly Patients after Predialysis Vascular Access Creation

Uniform vascular access guidelines for elderly patients may be inappropriate because of the competing risk of death, high rate of arteriovenous fistula (AVF) maturation failure, and poor vascular access outcomes in this population. However, the outcomes in elderly patients with advanced CKD who receive permanent vascular access before dialysis initiation are unclear. We identified a large nationally representative cohort of 3418 elderly patients (aged ≥ 70 years) with CKD undergoing predialysis AVF or arteriovenous graft (AVG) creation from 2004 to 2009, and assessed the frequencies of dialysis initiation, death before dialysis initiation, and dialysis-free survival for 2 years after vascular access creation. In all, 67% of patients with predialysis AVF and 71% of patients with predialysis AVG creation initiated dialysis within 2 years of access placement, but the overall risk of dialysis initiation was modified by patient age and race. Only one half of patients initiated dialysis with a functioning AVF or AVG; 46.8% of AVFs were created <90 days before dialysis initiation. Catheter dependence at dialysis initiation was more common in patients receiving predialysis AVF than in patients receiving AVG (46.0% versus 28.5%; P<0.001). In conclusion, most elderly patients with advanced CKD who received predialysis vascular access creation initiated dialysis within 2 years. As a consequence of late predialysis placement or maturation failure, almost one half of patients receiving AVFs initiated dialysis with a catheter. Insertion of an AVG closer to dialysis initiation may serve as a "catheter-sparing" approach and allow delay of permanent access placement in selected elderly patients with CKD.

Geographic variation and neighborhood factors are associated with low rates of pre-end-stage renal disease nephrology care

Geographic variation of pre-end-stage renal disease (pre-ESRD) nephrology care has not been studied across the United States. Here we sought to identify geographic differences in pre-ESRD care, assess for county-level geographic and sociodemographic risk factors, and correlate with patient outcomes using facility-level mortality. Patients from 5387 dialysis facilities across the United States from 2007 to 2010 were included from the Dialysis Facility Report. Marginal generalized estimating equations were used for modeling with geographic cluster analysis to detect clusters of facilities with low rates of pre-ESRD care. On average, 67% of patients received pre-ESRD care in the United States but with significant variability across regions ranging from 3 to 99%. Five geographic clusters of facilities with low rates of pre-ESRD care were the metropolitan areas of San Francisco, Los Angeles, Chicago, Miami, and Baltimore, along with Southern states along the Mississippi River. Dialysis facilities with the lowest rates of pre-ESRD care were more likely to be located in urban counties with high African-American populations and low educational attainment. A 10% higher proportion of patients receiving pre-ESRD care was associated with 1.3% lower patient mortality as reflected by facility-level mortality. Thus, geographic and sociodemographic factors can be used to design quality improvement initiatives to increase access to nephrology care nationwide and improve patient outcomes.

Association between non-matured arterio-venus fistula and blood pressure in hemodialysis patients

BACKGROUND

Chronic Kidney Disease (CKD) is a complicated kidney problem causing permanent renal failure in progressive stages. The final stage of CKD is called ESRD in which most accepted management is Hemodialysis (HD). Arterio-Venus Fistula (AVF) is the most practical way of making proper access to the blood circulatory system; however, maturation of the AVF is a challenge, since there are number of variables interfering with the whole process. The purpose of this study was to evaluate potentially modifiable factors associated with Maturation Time (MT) after creation of a Vascular Access (VA).

METHODS

In this cross-sectional study, a total of 87 patients referred to the Hasheminejad Kidney Center for AVF creation in 2010 were evaluated. Patients were evaluated before and after the AVF creation and risk factors such as history of blood pressure abnormalities, diabetes and congestive heart failure, as well as the successive development of AVF was studied and finally processed using 'data mining' technology.

RESULTS

The "Decision Trees" indicated the significant impact of the systolic blood pressure (SBP) in the delay of the patient's AVF maturation. Also, prediction of AVF maturation was made with 70.59% of precision in regard to their BP condition.

CONCLUSION

This study demonstrated that monitoring the SBP is one of the important steps in management of the cardiovascular variables producing any delay in the process of the patient's HD. Also the data mining method can discover the hidden relationship between the patient's medical conditions in order to predict the potential disorders.