Association of U.S. Dialysis facility neighborhood characteristics with facility-level kidney transplantation.

BACKGROUND: Improving access to optimal healthcare may depend on the attributes of neighborhoods where patients receive healthcare services. We investigated whether the characteristics of dialysis facility neighborhoods--where most patients with end-stage renal disease are treated--were associated with facility-level kidney transplantation. METHODS: We examined the association between census tract (neighborhood)-level sociodemographic factors and facility-level kidney transplantation rate in 3,983 U.S. dialysis facilities where kidney transplantation rates were high. Number of kidney transplants and total person-years contributed at the facility level in 2007-2010 were obtained from the Dialysis Facility Report and linked to the census tract data on sociodemographic characteristics from the American Community Survey 2006-2010 by dialysis facility location. We used multivariable Poisson models with generalized estimating equations to estimate the link between the neighborhood characteristics and transplant incidence. RESULTS: Dialysis facilities in the United States were located in neighborhoods with substantially greater proportions of black and poor residents, relative to the national average. Most facility neighborhood characteristics were associated with transplant, with incidence rate ratios (95% CI) for standardized increments (in percentage) of neighborhood exposures of: living in poverty, 0.88 (0.84-0.92), black race, 0.83 (0.78-0.89); high school graduates, 1.22 (1.17-1.26); and unemployed, 0.90 (0.85-0.95). CONCLUSION: Dialysis facility neighborhood characteristics may be modestly associated with facility rates of kidney transplantation. The success of dialysis facility interventions to improve access to kidney transplantation may partially depend on reducing neighborhood-level barriers.

High one year mortality in adults with sickle cell disease and end-stage renal disease.

Adequate pre-dialysis care reduces mortality among end-stage renal disease (ESRD) patients. We tested the hypothesis that individuals with ESRD due to sickle cell disease (SCD-ESRD) receiving pre-ESRD care have lower mortality compared to individuals without pre-ESRD care. We examined the association between mortality and pre-ESRD care in incident SCD-ESRD patients who started haemodialysis between 1 June, 2005 and 31 May, 2009 using data provided by the Centers for Medicare and Medicaid Services (CMS). SCD-ESRD was reported for 410 (0·1%) of 442 017 patients. One year after starting dialysis, 108 (26·3%) patients with incident ESRD attributed to SCD died; the hazard ratio (HR) for mortality among patients with SCD-ESRD compared to those without SCD as the primary cause of renal failure was 2·80 (95% confidence interval [CI] 2·31-3·38). Patients with SCD-ESRD receiving pre-dialysis nephrology care had a lower death rate than those with SCD-ESRD who did not receive pre-dialysis nephrology care (HR = 0·67, 95% CI 0·45-0·99). The one-year mortality rate following an ESRD diagnosis was almost three times higher in individuals with SCD when compared to those without SCD but with ESRD and could be attenuated by pre-dialysis nephrology care.

Epidemiology, geography and chronic kidney disease.

PURPOSE OF REVIEW: Geographic variation in the occurrence and outcomes of chronic kidney disease (CKD) is major area of study in epidemiology and health services and outcomes research. Geographic attributes may be as diverse as the physical, socioeconomic, and medical care characteristics of an environment. This review summarizes the recent literature pertaining to geographic risk factors and CKD. RECENT FINDINGS: Studies have reported on the association between CKD and physical attributes of place (ambient temperature and altitude), the impact of disasters on CKD populations, new diseases characterized by regional localization, national variations in CKD incidence and prevalence, regional variation in end-stage renal disease incidence, residential mobility and CKD risk factors, and geographic variations in CKD care. The emerging role of tools for geospatial studies - including multilevel analytical designs, which reduce the likelihood of an ecologically biased inference, and geographic information systems, which allow the simultaneous linkage, analysis, and mapping of geospatial data - is illustrated by these studies. SUMMARY: Our understanding of the occurrence and outcomes of CKD will continue to be expanded and deepened by the explicit study of attributes associated with place as a potential risk factor. Many of the studies reviewed are largely hypothesis generating, and a better understanding of the role of geography in the study of CKD awaits investigations that probe the mechanisms that link attributes of place to disease processes.

Geographic concentration of poverty and arteriovenous fistula use among ESRD patients.

There is substantial geographic variability in both incident and prevalent arteriovenous fistula (AVF) use among patients with ESRD. This study examined the degree to which these variations associate with poverty in the county of a patient's treatment center. We performed a cross-sectional study including 28,135 patients treated by 1127 hemodialysis centers in five ESRD networks (16 states) between June 1, 2005 and May 31, 2006. We used the 2000 U.S. Census to categorize county-level poverty and ascertained incident AVF use from the Medicare CMS 2728 form. We calculated the 30-month slope of change in AVF prevalence from monthly facility reports collected between 2003 and 2005. More than 33% of treatment centers were located in high-poverty counties. County poverty inversely associated with incident AVF use (P for trend = 0.001). In contrast, substantial increases in prevalent AVF rates from 30.9 to 38.6% (P < 0.001) among treatment centers did not associate with county poverty (P = 0.9519). In conclusion, the concentration of poverty in the county where a treatment is located associates with incident AVF use by patients with ESRD but not with subsequent improvement in AVF use among prevalent patients. These results suggest that the Medicare ESRD program may mitigate poverty effects on AVF use.

Treatment center and geographic variability in pre-ESRD care associate with increased mortality.

Late referral of patients with chronic kidney disease is associated with increased morbidity and mortality, but the contribution of center-to-center and geographic variability of pre-ESRD nephrology care to mortality of patients with ESRD is unknown. We evaluated the pre-ESRD care of > 30,000 incident hemodialysis patients, 5088 (17.8%) of whom died during follow-up (median 365 d). Approximately half (51.3%) of incident patients had received at least 6 mo of pre-ESRD nephrology care, as reported by attending physicians. Pre-ESRD nephrology care was independently associated with survival (odds ratio 1.54; 95% confidence interval 1.45 to 1.64). There was substantial center-to-center variability in pre-ESRD care, which was associated with increased facility-specific death rates. As the proportion of patients who were in a treatment center and receiving pre-ESRD nephrology care increased from lowest to highest quintile, the mortality rate decreased from 19.6 to 16.1% (P = 0.0031). In addition, treatment centers in the lowest quintile of pre-ESRD care were clustered geographically. In conclusion, pre-ESRD nephrology care is highly variable among treatment centers and geographic regions. Targeting these disparities could have substantial clinical impact, because the absence of > or = 6 mo of pre-ESRD care by a nephrologist is associated with a higher risk for death.

Effect of community characteristics on familial clustering of end-stage renal disease.

BACKGROUND: Lower socioeconomic status is generally associated with an increased risk of end-stage renal disease (ESRD). The relationship between community characteristics reflecting socioeconomic status and familial aggregation of common forms of ESRD has not been studied. METHODS: Demographic data and family history of ESRD were collected from 23,880 incident dialysis patients in ESRD Network 6 between 1995 and 2003. Addresses were geocoded and linked to the 2000 census 5-digit zip code-level database that includes community demographic, social and economic characteristics. Clustering of patients having a family history of ESRD at the community level was accounted for using a generalized estimating equations (GEE) model. Multivariate analysis estimated associations between family history of ESRD and community-level characteristics. RESULTS: Twenty-three percent of patients reported a family history of ESRD. After adjusting for individual demographic characteristics, multivariate analyses failed to reveal statistically significant relationships between a family history of ESRD and indicators of community socioeconomic status such as median household income, percentage high school graduates, percentage vacant housing units or ethnic composition. CONCLUSIONS: Although select community measures of lower socioeconomic status may contribute to the familial clustering of ESRD, non-socioeconomic factors, potentially inherited, appear to be more important contributors to familial aggregation of the common forms of ESRD.

Geographic region and racial variations in polypharmacy in the United States.

PURPOSE: Medications can have unintended effects. High medication use populations may benefit from increased regimen oversight. Limited knowledge exists concerning racial and regional polypharmacy variation. We estimated total medication distributions (excluding supplements) of American black and white adults and assessed racial and regional polypharmacy variation. METHODS: REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort data (n = 30,239 U.S. blacks and whites aged ≥45 years) were analyzed. Home pill bottle inspections assessed the last two weeks' medications. Polypharmacy (≥8 medications) was determined by summing prescription and/or over-the-counter ingredients. Population-weighted logistic regression assessed polypharmacy's association with census region, race, and sex. RESULTS: The mean ingredient number was 4.12 (standard error = 0.039), with 15.7% of REGARDS using 8 ingredients or more. In crude comparisons, women used more medications than men, and blacks and whites reported similar mean ingredients. A cross-sectional, logistic model adjusting for demographics, socioeconomics, and comorbidities showed increased polypharmacy prevalence in whites versus blacks (OR [95% CI]: 0.63, [0.55-0.72]), women (1.94 [1.68-2.23]), and Southerners (broadly Southeasterners and Texans; 1.48 [1.17-1.87]) versus Northeasterners (broadly New England and upper Mid-Atlantic). Possible limitations include polypharmacy misclassification and model misspecification. CONCLUSION: Polypharmacy is common. Race and geography are associated with polypharmacy variation. Further study of underlying factors explaining these differences is warranted.

High Costs of Dialysis Transportation in the United States: Exploring Approaches to a More Cost-effective Delivery System.

Background: The costs of transporting end-stage renal disease (ESRD) patients to dialysis centers are high and growing rapidly. Research has suggested that substantial cost savings could be achieved if medically appropriate transport was made available and covered by Medicare. Objectives: To estimate US dialysis transportation costs from a purchaser's perspective, and to estimate cost savings that could be achieved if less expensive means of transport were utilized. Methods: Costs were estimated using an actuarial model. Travel distance estimates were calculated using GIS software from patient ZIP codes and dialysis facility addresses. Cost and utilization estimates were derived from fee schedules, government reports, transportation websites and peer-reviewed literature. Results: The estimated annual cost of dialysis transportation in the United States is $3.0 billion, half of which is for ambulances. Most other costs are due to transport via ambulettes, wheelchair vans and taxis. Approximately 5% of costs incurred are for private vehicle or public transportation use. If ambulance use dropped to 1% of trips from the current 5%, costs could be reduced by one-third. Conclusions: Decision-makers should consider policies to reduce ambulance use, while providing appropriate levels of care.

Geographic disparities in patient travel for dialysis in the United States.

PURPOSE: To estimate travel distance and time for US hemodialysis patients and to compare travel of rural versus urban patients. METHODS: Dialysis patient residences were estimated from ZIP code-level patient counts as of February 2011 allocated within the ZIP code proportional to census tract-level population, obtained from the 2010 U.S. Census. Dialysis facility addresses were obtained from Medicare public-use files. Patients were assigned to an "original" and "replacement" facility, assuming patients used the facility closest to home and would select the next closest facility as a replacement, if a replacement facility was required. Driving distances and times were calculated between patient residences and facility locations using GIS software. FINDINGS: The mean one-way driving distance to the original facility was 7.9 miles; for rural patients average distances were 2.5 times farther than for urban patients (15.9 vs. 6.2 miles). Mean driving distance to a replacement facility was 10.6 miles, with rural patients traveling on average 4 times farther than urban patients to a replacement facility (28.8 vs. 6.8 miles). CONCLUSION: Rural patients travel much longer distances for dialysis than urban patients. Accessing alternative facilities, if required, would greatly increase rural patient travel, while having little impact on urban patients. Increased travel could have clinical implications as longer travel is associated with increased mortality and decreased quality of life.

The universal data collection surveillance system for rare bleeding disorders.

Since 1998, the CDC has coordinated a national public health surveillance project-the Universal Data Collection (UDC) program-on chronic, rare, inherited bleeding disorders. In this program, uniform data are gathered through a network of 130 hemophilia treatment centers (HTCs) throughout the U.S. and its territories. Initially, the program was designed to address two primary goals: (1) establishment of a blood-safety monitoring system among people with bleeding disorders, and (2) collection of a uniform set of clinical outcomes data that could be used to monitor trends in the prevalence of infectious diseases and joint complications among this population. To this end, the program has been acquiring useful longitudinal data to monitor complications of bleeding disorders. For example, with the establishment of range-of-motion measurements for joints as required data elements, a large database has been developed for studies examining risk factors for joint-disease progression. The UDC program data have been used to provide evidence for a national prevention campaign to promote the need for patients with hemophilia to establish or maintain a healthy weight to help prevent joint disease. Risk factors leading to complications such as joint infection have also been identified. The application of geographic information systems technology to UDC program data has helped identify needs for outreach and availability of blood products and sources of care. Future analyses of data collected on babies, women, and individuals with rarer bleeding disorders than hemophilia will provide further information, leading to improved public health prevention strategies.