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1.  Pre-end-stage renal disease care not associated with dialysis facility neighborhood poverty in the United States 
American journal of nephrology  2014;39(1):50-58.
Receipt of nephrology care prior to end-stage renal disease (ESRD) is a strong predictor of decreased mortality and morbidity, and neighborhood poverty may influence access to care. Our objective was to examine whether neighborhood poverty is associated with lack of pre-ESRD care at dialysis facilities.
In a multi-level ecological study using geospatially linked 2007-2010 Dialysis Facility Report and 2006-2010 American Community Survey data, we examined whether high neighborhood poverty (≥20% of households in census tract living below poverty) was associated with dialysis facility-level lack of pre-ESRD care (percentage of patients with no nephrology care prior to dialysis start) in mixed-effects models, adjusting for facility and neighborhood confounders and allowing for neighborhood and regional random effects.
Among the 5184 facilities examined, 1778 (34.3%) were located in a high poverty area. Lack of pre-ESRD care was similar in poverty areas (30.8%) and other neighborhoods (29.6%). With adjustment, the absolute increase in percentage of patients at a facility with no pre-ESRD care associated with facility location in a poverty area vs. other neighborhood was only 0.08% (95% CI: -1.32%, 1.47%; P=0.9). Potential effect modification by race and income inequality was detected.
Despite previously reported detrimental effects of neighborhood poverty on health, facility neighborhood poverty was not associated with receipt of pre-ESRD care, suggesting no need to target interventions to increase access to pre-ESRD care at facilities in poorer geographic areas.
PMCID: PMC3958935  PMID: 24434854
neighborhood; poverty; end-stage renal disease; access to care
2.  Serum Fructosamine and Glycated Albumin and Risk of Mortality and Clinical Outcomes in Hemodialysis Patients 
Diabetes Care  2013;36(6):1522-1533.
Assays for serum total glycated proteins (fructosamine) and the more specific glycated albumin may be useful indicators of hyperglycemia in dialysis patients, either as substitutes or adjuncts to standard markers such as hemoglobin A1c, as they are not affected by erythrocyte turnover. However, their relationship with long-term outcomes in dialysis patients is not well described.
We measured fructosamine and glycated albumin in baseline samples from 503 incident hemodialysis participants of a national prospective cohort study, with enrollment from 1995–1998 and median follow-up of 3.5 years. Outcomes were all-cause and cardiovascular disease (CVD) mortality and morbidity (first CVD event and first sepsis hospitalization) analyzed using Cox regression adjusted for demographic and clinical characteristics, and comorbidities.
Mean age was 58 years, 64% were white, 54% were male, and 57% had diabetes. There were 354 deaths (159 from CVD), 302 CVD events, and 118 sepsis hospitalizations over follow-up. Both fructosamine and glycated albumin were associated with all-cause mortality; adjusted HR per doubling of the biomarker was 1.96 (95% CI 1.38–2.79) for fructosamine and 1.40 (1.09–1.80) for glycated albumin. Both markers were also associated with CVD mortality [fructosamine 2.13 (1.28–3.54); glycated albumin 1.55 (1.09–2.21)]. Higher values of both markers were associated with trends toward a higher risk of hospitalization with sepsis [fructosamine 1.75 (1.01–3.02); glycated albumin 1.39 (0.94–2.06)].
Serum fructosamine and glycated albumin are risk factors for mortality and morbidity in hemodialysis patients.
PMCID: PMC3661814  PMID: 23250799
3.  Americans’ Use of Dietary Supplements That Are Potentially Harmful in CKD 
The prevalence in the United States of dietary supplement use that may be harmful to those with chronic kidney disease (CKD) is unknown. We sought to characterize potentially harmful supplement use by individual CKD status.
Study Design
Cross-sectional national survey (National Health and Nutrition Examination Survey, 1999-2008)
Setting & Participants
Community-based survey of 21,169 non-pregnant, non-institutionalized U.S. civilian adults (≥20 years)
CKD status (no CKD, at risk for CKD [presence of diabetes, hypertension and/or cardiovascular disease], stage 1/2 [albuminuria only (albumin-creatinine ratio ≥30 mg/g)], or stage 3/4 [estimated glomerular filtration rate of 15-59 ml/min/1.73 m2]).
Self-reported use of dietary supplements containing any of 37 herbs the National Kidney Foundation identified as potentially harmful in the setting of CKD.
Albuminuria and estimated glomerular filtration rate assessed from urine and blood samples; demographics and comorbid conditions assessed by standardized questionnaire.
An estimated 8.0% of U.S. adults reported potentially harmful supplement use within the last 30 days. Lower crude estimated prevalence of potentially harmful supplement use was associated with higher CKD severity (no CKD, 8.5%; at risk, 8.0%; stage 1/2, 6.1%; and stage 3/4, 6.2%; p<0.001). However, after adjustment for confounders, those with or at risk for CKD were as likely to use a potentially harmful supplement as those without CKD: at-risk OR, 0.93 (95% CI, 0.79 -1.09); stage 1/2 OR, 0.83 (95% CI, 0.64 -1.08); stage 3/4 OR, 0.87 (95% CI, 0.63 -1.18); all vs. no CKD.
Herb content was not available and the list of potentially harmful supplements examined is unlikely to be exhaustive.
The use of dietary supplements potentially harmful to people with CKD is common, regardless of CKD status. Healthcare providers should discuss the use and potential risks of supplements with patients with and at risk for CKD.
PMCID: PMC3628413  PMID: 23415417
4.  Healthy Behaviors, Risk Factor Control and Awareness of Chronic Kidney Disease 
American journal of nephrology  2013;37(2):135-143.
The association between chronic kidney disease (CKD) awareness and healthy behaviors is unknown. We examined whether CKD self-recognition is associated with healthy behaviors and achieving risk-reduction targets known to decrease risk of cardiovascular morbidity and CKD progression.
CKD awareness, defined as a “yes” response to “Has a doctor or other health professional ever told you that you had kidney disease?”, was examined among adults with CKD (eGFR < 60 ml/min/1.73 m2) who participated in the REasons for Geographic and Racial Differences in Stroke study. Odds of participation in healthy behaviors (tobacco avoidance, avoidance of regular NSAID use, physical activity) and achievement of risk reduction targets (ACEI/ARB use, systolic blood pressure (SBP) control and glycemic control among those with diabetes) among those aware vs. unaware of their CKD were determined by logistic regression, controlling for socio-demographics, access to care and co-morbid conditions. SBP control was defined as < 130 mmHg (primary definition) or < 140 mmHg (secondary definition).
Of 2,615 participants, only 6% (n=166) were aware of having CKD. Those who were aware had 82% higher odds of tobacco avoidance compared to those unaware [adjusted odds ratio =1.82, 95% CI (1.02–3.24)]. CKD awareness was not associated other healthy behaviors or achievement of risk-reduction targets.
Awareness of CKD was only associated with participation in one healthy behavior and was not associated with achievement of risk-reduction targets. To encourage adoption of healthy behaviors, a better understanding of barriers to participation in CKD-healthy behaviors is needed. Keywords: chronic kidney disease, awareness, behaviors, self-management
PMCID: PMC3649001  PMID: 23392070
Chronic kidney disease; awareness; self-management; behaviors
5.  Chronic Kidney Disease Identification in a High-Risk Urban Population: Does Automated eGFR Reporting Make a Difference? 
Whether automated estimated glomerular filtration rate (eGFR) reporting for patients is associated with improved provider recognition of chronic kidney disease (CKD), as measured by diagnostic coding of CKD in those with laboratory evidence of the disease, has not been explored in a poor, ethnically diverse, high-risk urban patient population. A retrospective cohort of 237 adult patients (≥20 years) with incident CKD (≥1 eGFR ≥60 ml/min/1.73 m2, followed by ≥2 eGFRs <60 ml/min/1.73 m2 ≥3 months apart)—pre- or postautomated eGFR reporting—was identified within the San Francisco Department of Public Health Community Health Network (January 2005–July 2009). Patients were considered coded if any ICD-9-CM diagnostic codes for CKD (585.x), other kidney disease (580.x–581.x, 586.x), or diabetes (250.4) or hypertension (403.x, 404.x) CKD were present in the medical record within 6 months of incident CKD. Multivariable logistic regression was used to obtain adjusted odds ratios (ORs) for CKD coding. We found that, pre-eGFR reporting, 42.5 % of incident CKD patients were coded for CKD. Female gender, increased age, and non-Black race were associated with lower serum creatinine and lower prevalence of coding but comparable eGFR. Prevalence of coding was not statistically significantly higher overall (49.6 %, P = 0.27) or in subgroups after the institution of automated eGFR reporting. However, gaps in coding by age and gender were narrowed post-eGFR, even after adjustment for sociodemographic and clinical characteristics: 47.9 % of those <65 and 30.3 % of those ≥65 were coded pre-eGFR, compared to 49.0 % and 52.0 % post-eGFR (OR = 0.43 and 1.16); similarly, 53.2 % of males and 25.4 % of females were coded pre-eGFR compared to 52.8 % and 44.0 % post-eGFR (OR 0.28 vs. 0.64). Blacks were more likely to be coded in the post-eGFR period: OR = 1.08 and 1.43 (Pinteraction > 0.05). Automated eGFR reporting may help improve CKD recognition, but it is not sufficient to resolve underidentification of CKD by safety net providers.
PMCID: PMC3531349  PMID: 22684427
Chronic kidney disease; Diagnostic coding; Estimated glomerular filtration rate; Female; African American
6.  Is Awareness of Chronic Kidney Disease Associated with Evidence-Based Guideline-Concordant Outcomes? 
American Journal of Nephrology  2012;35(2):191-197.
Awareness of chronic kidney disease (CKD) is low. Efforts are underway to increase recognition of CKD among patients, assuming that such an increase will lead to better outcomes through greater adherence to proven therapies. Few studies have tested this assumption.
CKD awareness, defined by a ‘yes’ answer to ‘Have you ever been told by a healthcare provider you have weak or failing kidneys?’, was assessed among 2,404 adults with CKD stages 1–4, who participated in the 2003–2008 National Health and Nutrition Examination Surveys. Odds of blood pressure (BP) control, self-reported use of angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB), and glycemic control, were determined among those aware vs. unaware of their CKD.
Optimal BP control, ACEI/ARB use and glycemic control were low in the US adult population with CKD, although there was a recent increase in attainment of guideline-concordant BP control. Odds of BP control and ACEI/ARB use were not different among individuals aware of their CKD compared to those unaware (adjusted odds ratio (AOR) 0.91; 95% CI 0.52–1.58 and AOR 0.75; 0.44–1.30, respectively). CKD awareness among diabetic participants was not associated with glycemic control (AOR 0.41; 95% CI 0.14–1.18).
Awareness of CKD is not associated with more optimal BP control, ACEI/ARB use or glycemic control. Future efforts in this area should further explore the measurement of CKD awareness and behaviors associated with CKD awareness.
PMCID: PMC3326277  PMID: 22286715
Chronic kidney disease; Awareness; National Health And Nutrition Examination Survey (NHANES); Guidelines
7.  Medicare immunosuppressant coverage and access to kidney transplantation: a retrospective national cohort study 
In December 2000, Medicare eliminated time limitations in immunosuppressant coverage after kidney transplant for beneficiaries age ≥65 and those who were disabled. This change did not apply to younger non-disabled beneficiaries who qualified for Medicare only because of their end-stage renal disease (ESRD). We sought to examine access to waitlisting for kidney transplantation in a cohort spanning this policy change.
This was a retrospective cohort analysis of 241,150 Medicare beneficiaries in the United States Renal Data System who initiated chronic dialysis between 1/1/96 and 11/30/03. We fit interrupted time series Cox proportional hazard models to compare access to kidney transplant waitlist within 12 months of initiating chronic dialysis by age/disability status, accounting for secular trends.
Beneficiaries age <65 who were not disabled were less likely to be waitlisted after the policy change (hazard ratio (HR) for the later vs. earlier period, 0.93, p = 0.002), after adjusting for sociodemographic factors, co-morbid conditions, income, and ESRD network. There was no evidence of secular trend in this group (HR per year, 1.00, p = 0.989). Likelihood of being waitlisted among those age ≥65 or disabled increased steadily throughout the study period (HR per year, 1.04, p < 0.001), but was not clearly affected by the policy change (HR for the immediate effect of policy change, 0.93, p = 0.135).
The most recent extension in Medicare immunosuppressant coverage appears to have had little impact on the already increasing access to waitlisting among ≥65/ disabled beneficiaries eligible for the benefit but may have decreased access for younger, non-disabled beneficiaries who were not. The potential ramifications of policies on candidacy appeal for access to kidney transplantation should be considered.
PMCID: PMC3470983  PMID: 22894737
8.  Chronic kidney disease and use of dental services in a united states public healthcare system: a retrospective cohort study 
BMC Nephrology  2012;13:16.
As several studies have shown an association between periodontal disease and chronic kidney disease (CKD), regular dental care may be an important strategy for reducing the burden of CKD. Access to dental care may be limited in the US public health system.
In this retrospective cohort study of 6,498 adult patients with (n = 2,235) and without (n = 4,263) CKD and at least 12 months of follow-up within the San Francisco Department of Public Health Community Health Network clinical databases, we examined the likelihood of having a dental visit within the observation period (2005-2010) using Cox proportional hazards models. To determine whether dental visits reflected a uniform approach to preventive service use in this setting, we similarly examined the likelihood of having an eye visit among those with diabetes, for whom regular retinopathy screening is recommended. We defined CKD status by average estimated glomerular filtration rate based on two or more creatinine measurements ≥ 3 months apart (no CKD, ≥ 60 ml/min/1.73 m2; CKD, < 60 ml/min/1.73 m2).
Only 11.0% and 17.4% of patients with and without CKD, respectively, had at least one dental visit. Those with CKD had a 25% lower likelihood of having a dental visit [HR = 0.75, 95% CI (0.64-0.88)] than those without CKD after adjustment for confounders. Among the subgroup of patients with diabetes, 11.8% vs. 17.2% of those with and without CKD had a dental visit, while 58.8% vs. 57.8% had an eye visit.
Dental visits, but not eye visits, in a US public healthcare setting are extremely low, particularly among patients with CKD. Given the emerging association between oral health and CKD, addressing factors that impede dental access may be important for reducing the disparate burden of CKD in this population.
PMCID: PMC3368751  PMID: 22471751
9.  Soluble P-Selectin Levels Are Associated with Cardiovascular Mortality and Sudden Cardiac Death in Male Dialysis Patients 
American Journal of Nephrology  2011;33(3):224-230.
P-selectin is released by activated platelets and endothelium contributing to inflammation and thrombosis. We evaluated the association between soluble P-selectin and atherosclerotic cardiovascular disease (ASCVD) in dialysis patients.
We measured soluble P-selectin in serum from 824 incident dialysis patients. Using Cox proportional hazards models, we modeled the association of P-selectin levels with ASCVD events, cardiovascular mortality and sudden cardiac death.
After adjustment for demographics, comorbidity and traditional cardiovascular risk factors, higher P-selectin levels were associated with increased risk of ASCVD and cardiovascular mortality among males (p = 0.02 and p = 0.01, respectively), but not females (p = 0.52 and p = 0.31, respectively; p interaction = 0.003), over a median of 38.2 months. Higher P-selectin was associated with a greater risk of sudden cardiac death among males (p = 0.05). The associations between increasing P-selectin and cardiovascular mortality as well as sudden cardiac death in males persisted after adjustment for C-reactive protein, interleukin-6, serum albumin and platelet count (p = 0.01 and p = 0.03, respectively). The risk for sudden cardiac death was more than 3 times greater for males in the highest tertile of soluble P-selectin compared with the lowest tertile after adjustment (HR: 3.19; 95% CI: 1.18 – 8.62; p = 0.02).
P-selectin is associated with ASCVD, cardiovascular mortality and sudden cardiac death among male dialysis patients.
PMCID: PMC3064942  PMID: 21346329
Cardiovascular disease; Dialysis; End-stage renal disease; Inflammation; Sudden cardiac death; P-selectin
10.  Association of CKD with Disability in the United States 
Little is known about disability in early-stage chronic kidney disease (CKD).
Study Design
Cross-sectional national survey (National Health and Nutrition Examination Survey 1999–2006).
Setting and Participants
Community-based survey of 16,011 non-institutionalized U.S. civilian adults (≥20 years).
CKD, categorized as: no CKD, stages 1 and 2 [albuminuria and estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2], and stages 3 and 4 (eGFR 15–59).
Self-reported disability, defined by limitations in working, walking, and cognition; and difficulties in activities of daily living (ADL), instrumental ADL, leisure and social activities, lower extremity mobility, and general physical activity.
Albuminuria and eGFR assessed from urine and blood samples; disability, demographics, access to care, and comorbid conditions assessed by standardized questionnaire.
Age-adjusted prevalence of reported limitations was generally significantly greater with CKD: e.g., difficulty with ADLs was reported by 17.6%, 24.7%, and 23.9% of older (≥65 years) and 6.8%, 11.9%, and 11.0% of younger (20–64 years) adults with no CKD, stages 1 and 2, and stages 3 and 4, respectively. CKD was also associated with greater reported limitations and difficulty in other activities after age adjustment, including instrumental ADL, leisure and social activities, lower extremity mobility, and general physical activity. Other demographics, socioeconomic status, and access to care generally only slightly attenuated the observed associations, particularly among older individuals; adjustment for cardiovascular disease, arthritis, and cancer attenuated most associations such that statistical significance was no longer achieved.
Inability to establish causality and possible unmeasured confounding.
CKD is associated with higher prevalence of disability in the United States. Age and other comorbid conditions account for most, but not all, of this association.
PMCID: PMC3025052  PMID: 21036441
chronic kidney disease; disability; activities of daily living; limitations; employment; physical functioning; cognitive functioning
11.  Validation of CKD and Related Conditions in Existing Datasets: A Systematic Review 
Accurate classification of individuals with kidney disease is vital to research and public health efforts aimed at improving health outcomes. Our objective was to identify and synthesize published literature evaluating the accuracy of existing data sources related to kidney disease.
Study design
A systematic review of studies seeking to validate the accuracy of the underlying data relevant to kidney disease.
Setting & Population
U.S.-based and international studies covering a wide range of both outpatient and inpatient study populations.
Selection Criteria for Studies
Any English-language study investigating the prevalence or etiology of kidney disease, the existence of co-morbid conditions, or the cause of death in those with CKD. All definitions and stages of CKD, including end-stage renal disease (ESRD), were accepted.
Index Tests
Presence of a kidney disease-related variable in existing datasets, including administrative datasets and disease registries.
Reference Tests
Presence of a kidney disease-related variable defined by laboratory criteria or medical record review.
Thirty studies were identified. Most studies investigated the accuracy of kidney disease reporting, comparing coded renal disease to that defined by estimated glomerular filtration rate (eGFR). Sensitivity of coded renal disease varied widely (0.08–0.83). Specificity was higher, with all studies reporting values of ≥0.90. The studies evaluating the etiology of CKD, comorbidities, and the cause of death in CKD all used ESRD or transplant populations exclusively, and accuracy was highly variable when compared to ESRD registry data.
Only English-language studies were evaluated.
Given the heterogeneous results of validation studies, a variety of attributes of existing data sources, including the accuracy of individual data items within these sources, should be carefully considered prior to use in research, quality improvement and public health efforts.
PMCID: PMC2978782  PMID: 20692079
12.  Association of Residual Urine Output with Mortality, Quality of Life, and Inflammation in Incident Hemodialysis Patients: The CHOICE (Choices for Healthy Outcomes in Caring for End-Stage Renal Disease) Study 
Residual kidney function (RKF) is associated with improved survival in peritoneal dialysis patients but its role in hemodialysis patients is less well known. Urine output may provide an estimate of RKF. The aim of our study was to determine the association of urine output with mortality, quality of life (QOL) and inflammation in incident hemodialysis patients.
Study Design
Nationally representative prospective cohort study
Setting & Participants
734 incident hemodialysis participants treated in 81 clinics; enrollment, 1995-1998, follow-up until December 2004.
Urine output, defined as producing at least 250 mL (1 cup) of urine daily, ascertained by questionnaires at baseline and year 1.
Outcomes & Measurements
Primary outcomes were all-cause and cardiovascular (CVD) mortality, analyzed using Cox regression adjusted for demographic, clinical and treatment characteristics. Secondary outcomes were QOL, inflammation (CRP and interleukin-6 [IL-6] levels) and erythropoietin (EPO) requirements.
617/734 (84%) participants reported urine output at baseline and 163/579 (28%) at year 1. Baseline urine output was not associated with survival. Urine output at year 1, indicating preserved RKF, was independently associated with lower all-cause mortality (Hazard Ratio [HR], 0.70; 95% Confidence Interval [CI], 0.52-0.93; p=0.02) and a trend towards lower CVD mortality (HR, 0.69; 95% CI, 0.45-1.05; p=0.09). Participants with urine output at baseline reported better QOL and had lower CRP (p=0.02) and IL-6 (p=0.03) levels. Importantly, EPO dose was 12,000 units/week lower in those with urine output at year 1 compared with those without (p=0.001).
Urine volume was measured in only a subset of patients (42%) but was in agreement with self-report (p<0.001).
RKF in hemodialysis patients is associated with better survival and QOL, lower inflammation and significantly less EPO use. RKF should be monitored routinely in hemodialysis patients. Development of methods to assess and preserve RKF is important and may improve dialysis care.
PMCID: PMC2910835  PMID: 20605303
End-stage Renal Disease; Hemodialysis; Residual Kidney Function; Mortality; Quality of Life; Inflammation
13.  Awareness of Chronic Kidney Disease among Patients and Providers 
Earlier recognition of chronic kidney disease (CKD) could slow progression, prevent complications, and reduce cardiovascular-related outcomes. However, current estimates of CKD awareness indicate that both patient- and provider-level awareness remain unacceptably low. Many of the factors that are possibly associated with CKD awareness, which could help guide implementation of awareness efforts, have yet to be fully examined. Also, little is known regarding whether increased patient or provider awareness improves clinical outcomes or whether there are possible negative consequences of awareness for CKD patients. Further research is necessary to continue to design and refine awareness campaigns aimed at both patients and providers, but there is an immediate need for dissemination of basic CKD information, given both the high prevalence of CKD and its risk factors and the low estimated awareness of CKD.
PMCID: PMC2864779  PMID: 20439091
chronic kidney disease; awareness; knowledge; patient; provider; review
14.  Prevalence of Chronic Kidney Disease in Persons with Undiagnosed or Pre-Hypertension in the U.S 
Hypertension  2010;55(5):1102-1109.
Hypertension is both a cause and consequence of chronic kidney disease, but the prevalence of chronic kidney disease throughout the diagnostic spectrum of blood pressure has not been established. We determined the prevalence of chronic kidney disease within blood pressure categories in 17,794 adults surveyed by the National Health and Nutrition Examination Survey during 1999–2006. Diagnosed hypertension was defined as self-reported provider diagnosis (n=5,832); undiagnosed hypertension was defined as systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg, without report of provider diagnosis (n=3,046); pre-hypertension was defined as systolic blood pressure ≥120 and < 140 mmHg or diastolic blood pressure ≥80 and < 90 mmHg (n=3,719); and normal was defined as systolic blood pressure < 120 mmHg and diastolic blood pressure < 80 mmHg (n=5,197). Chronic kidney disease was defined as estimated glomerular filtration rate 15–60 ml/min/1.73m2 or urinary albumin-creatinine ratio > 30 mg/g. Prevalence of chronic kidney disease among those with pre- and undiagnosed hypertension was 17.3% and 22.0%, respectively, compared to 27.5% with diagnosed hypertension and 13.4% with normal blood pressure, after adjustment for age, gender and race in multivariable logistic regression. This pattern persisted with varying definitions of kidney disease; macro-albuminuria (urinary albumin-creatinine ratio > 300 mg/g) had the strongest association with increasing blood pressure category [odds ratio 2.37 (95% confidence interval, 2.00–2.81)]. Chronic kidney disease is prevalent in undiagnosed and pre-hypertension. Earlier identification and treatment of both these conditions may prevent or delay morbidity and mortality from chronic kidney disease.
PMCID: PMC2880533  PMID: 20308607
epidemiology; albuminuria; renal; prevention; awareness; surveillance
15.  Inpatient Hemodialysis Initiation: Reasons, Risk Factors and Outcomes 
Nephron. Clinical Practice  2009;114(1):c19-c28.
Inpatient initiation of chronic hemodialysis is considered undesirable because of cost and possible harms of hospitalization. We examined the patient characteristics and outcomes associated with inpatient initiation.
In a prospective cohort study of incident dialysis patients, the independent association of inpatient hemodialysis initiation with patient outcomes was assessed in multivariable analyses with adjustment for patient characteristics and propensity for inpatient initiation.
A total of 410 of 652 (63%) hemodialysis patients began as inpatients; uremia and volume overload were the most commonly documented reasons. Compared to outpatients, inpatients were more likely to be unmarried, report less social support, have multiple comorbidities and be referred to a nephrologist 4 months or less prior to initiation. Inpatient initiation was protective for subsequent all-cause hospitalization (incidence rate ratio (IRR) = 0.92, confidence interval (CI) 0.89–0.94); this was most pronounced among those who had the highest propensity for inpatient initiation (IRR = 0.66, CI 0.56–0.78), including those referred late to nephrology. Similar results were found for infectious hospitalization. Mortality [hazard ratio = 1.03, CI 0.82–1.30] and cardiovascular events were not significantly different for inpatients versus outpatients.
Inpatient hemodialysis initiation has a protective association with hospitalization among those patients referred late to nephrology, with multiple comorbidities and/or little social support.
PMCID: PMC2842162  PMID: 19816040
End-stage renal disease; Hospitalization; Late referral; Mortality; Social support
16.  Cerebrovascular Disease Incidence, Characteristics, and Outcomes in Patients Initiating Dialysis: The CHOICE (Choices for Healthy Outcomes in Caring for ESRD) Study 
Stroke is the third most common cause of cardiovascular disease death in patients on dialysis; however, characteristics of cerebrovascular disease, including clinical subtypes and subsequent consequences, have not been well described.
Study Design
Prospective national cohort study, the Choices for Healthy Outcomes in Caring for ESRD (CHOICE) study.
Settings & Participants
1,041 incident dialysis patients treated in 81 clinics, enrolled from 10/95–7/98, followed until 12/31/2004.
Time from dialysis initiation.
Outcomes & Measurements
Cerebrovascular disease events were defined as non-fatal (hospitalized stroke, carotid endarterectomy) and fatal (stroke death) events after dialysis initiation. Stroke subtypes were classified using standardized criteria from the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) system. Incidence of cerebrovascular event subtypes were analyzed using time-to-event analyses accounting for competing risk of death. Clinical outcomes after stroke were abstracted from medical records.
A total of 165 participants experienced a cerebrovascular event with an overall incidence of 4.9 per 100 person-years. Ischemic stroke was the most common (76% of all 200 events) with cardioembolism subtype accounting for 28% of the 95 abstracted ischemic events. The median time from onset of symptoms to first stroke evaluation was 8.5 hours (25th and 75th percentiles 1, 42 hours), with only 56% of patients successfully escaping death, nursing home, or a skilled nursing facility.
Relatively small sample size limits power to determine risk factors.
Cerebrovascular disease is common in dialysis patients, is identified late, and carries a significant risk of morbidity and mortality. Stroke etiologic subtypes on dialysis are multifactorial, suggesting risk factors may change the longer one has ESRD. Further studies are needed to address the poor prognosis through prevention, early identification, and treatment.
PMCID: PMC2744381  PMID: 19376618
Cerebrovascular disease; Stroke; Dialysis; Prognosis; Epidemiology
Hypertension  2009;54(1):47-56.
Recent guidelines recommending more aggressive blood pressure control in patients with chronic kidney disease have unknown impact. We assessed trends in and predictors of blood pressure control in 8,829 adult NHANES 1999–2006 participants with hypertension (self-report, measured blood pressure, or use of anti-hypertensive medications), without (n=7,178) and with (n=1,651) chronic kidney disease. Uncontrolled blood pressure was defined as: general definition, systolic blood pressure ≥140/diastolic blood pressure ≥90 mmHg; disease-specific definition, ≥130/≥85 (1999–2002) and ≥130/≥80 (2003–2006) mmHg for those with chronic kidney disease (estimated GFR <60 ml/min/1.73 m2) or diabetes (self-report). Proportions with uncontrolled blood pressure in 1999–2006 were greater in those with chronic kidney disease versus those without chronic kidney disease [51.5% vs. 48.7% (general definition, P=0.122) and 68.8% vs. 51.7% (disease-specific definition; P<0.001)]. In those with chronic kidney disease, there were significant decreases in uncontrolled blood pressure over time [55.9% to 47.8% (general definition, P=0.011)]. With adjustment for demographic, socioeconomic, and clinical variables, older age (P<0.001) and lack of anti-hypertensive treatment (P<0.001) were associated with uncontrolled blood pressure, regardless of chronic kidney disease status; non-white race (P=0.002) was associated in those without chronic kidney disease, whereas female sex (P=0.030) was associated in those with chronic kidney disease. Multiple medications (P<0.001) and angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (P=0.001) were associated with less uncontrolled blood pressure. Although some improvement has occurred over time, uncontrolled blood pressure remains highly prevalent, especially in chronic kidney disease and in non-whites, older persons, and females. Therapy appears suboptimal.
PMCID: PMC2720323  PMID: 19470881
blood pressure control; prevalence; trends; risk factors; treatment guidelines; chronic kidney disease
18.  Accuracy of Patients’ Reports of Comorbid Disease and Their Association with Mortality in End-Stage Renal Disease 
Patient awareness of chronic diseases is low. Unawareness may represent poor understanding of chronic illness and may be associated with poor outcomes in end-stage renal disease (ESRD) patients.
Study Design
Concurrent, prospective national cohort study.
Setting & Participants
Incident hemodialysis and peritoneal dialysis patients enrolled in the Choices for Healthy Outcomes In Caring for ESRD (CHOICE) Study and followed until 2004.
Inaccurate patient self-report of eight comorbid diseases as compared to the medical record.
Outcomes & Measurements
All-cause mortality was the primary outcome. Cox proportional hazard models were used to assess the contribution of demographics and clinical measures in the relation of inaccurate self-report to mortality.
In 965 patients, the proportion of inaccurate self-reporters ranged from 3% for diabetes mellitus to 35% for congestive heart failure. Generally, inaccurate self-reporters were older and had more chronic diseases. A higher risk of death was found for inaccurate self-reporters of ischemic heart disease (Hazard Ratio (HR) [95% CI] =1.34 [1.12 –1.59]; p=0.001), coronary intervention (HR=1.46 [1.08 – 1.97]; p=0.01), and chronic obstructive pulmonary disease (COPD) (HR=1.40 [1.14–1.70]; p=0.001). The higher risk of death remained significant for COPD (HR=1.36 [1.11 – 1.66]; p=0.003) after adjustment for age, sex, and race. In patients receiving peritoneal dialysis, a higher risk of death (HR=2.06 [1.34 – 3.15]; p=0.001) was found for inaccurate self-reporters of ischemic heart disease.
Includes potential for residual confounding, medical record error, misclassification of patient accuracy of self-report, and low inaccurate self-report of some chronic diseases, reducing the power to measure associations.
Accuracy of self-report depends upon the specific comorbid disease. ESRD patients, especially those receiving peritoneal dialysis, who inaccurately report heart disease may be less aware of their chronic comorbid disease and may be at higher risk of mortality compared to those who accurately report their comorbid disease.
PMCID: PMC2587104  PMID: 18589216
End-stage renal disease (ESRD); mortality; self-report; awareness; comorbid disease; outcomes
19.  Phosphate Levels and Blood Pressure in Incident Hemodialysis Patients: A Longitudinal Study 
An elevated serum phosphate level in hemodialysis patients has been associated with mineral deposition in blood vessels. We studied a possible physiologic consequence of hyperphosphatemia by examining the relation between serum phosphate levels and blood pressure in 707 incident hemodialysis patients from 75 clinics who were enrolled in a prospective cohort study. We conducted cross-sectional and longitudinal multiple linear regression analyses, adjusting for demographics, medical history and laboratory factors. In cross-sectional analyses at baseline, elevated serum phosphate was associated with higher pre-dialysis systolic blood pressure (SBP) and pulse pressure (PP) at the start of dialysis; each 1 mg/dL higher phosphate level was associated with 1.77 mmHg higher SBP. In multivariable adjusted longitudinal analyses, for each 1 mg/dL higher serum phosphate at baseline, SBP was higher at: 3 months, 1.36 mmHg (p=0.005); 6 months, 1.13 mmHg (p=0.035); 12 months, 1.65 mmHg (p=0.008); 18 months, 1.44 mmHg (p=0.031); and 27 months, 2.54 mmHg (p=0.002); and PP was higher at: 3 months, 0.80 mmHg (p=0.027); 6 months, 0.91 mmHg (p=0.022); 12 months, 1.45 mmHg (p<0.001); 18 months, 1.06 mmHg (p=0.026); and 27 months, 1.37 mmHg (p=0.020). This study suggests that serum phosphate level is strongly and independently associated with blood pressure in hemodialysis patients. The effect of rigorous control of serum phosphate levels on arterial stiffness and blood pressure should be studied in clinical trials.
PMCID: PMC2529257  PMID: 18565483
phosphate; blood pressure; hemodialysis
20.  Association of Peritoneal Dialysis Clinic Size with Clinical Outcomes 
Very few studies have addressed the relationship between number of peritoneal dialysis (PD) patients treated at a clinic (PD clinic size) and clinical outcomes. In a national prospective cohort study of incident PD patients (n=236, from 26 clinics), we examined whether being treated at a larger PD clinic [≥50 PD patients (n=3 clinics) vs. <50 PD patients (n=23 clinics)] was associated with better patient outcomes, including fewer switches to hemodialysis, fewer cardiovascular events, lower cardiovascular mortality, and lower all-cause mortality.
Multivariable Cox models were used to assess relative hazards (RHs) for modality switches, cardiovascular events, cardiovascular deaths, and all-cause deaths by PD clinic size. All models were adjusted for demographics, comorbidities, laboratory values, and clinic years in operation.
Being treated at a clinic with ≥50 patients was associated with fewer switches to hemodialysis (RH=0.13, 95% CI, 0.06-0.31) and fewer cardiovascular events (RH=0.62, 95% CI, 0.06-0.98). No associations of PD clinic size with cardiovascular or all-cause mortality were seen.
PD patients that are treated at clinics with greater numbers of PD patients may have better outcomes in terms of technique failure and cardiovascular morbidity. PD clinic size may act as a proxy of greater PD experience, more focus on the modality, and better PD practices at the clinic, resulting in better outcomes.
PMCID: PMC2686121  PMID: 19458300
peritoneal dialysis; clinic size; technique failure; cardiovascular morbidity; mortality
21.  Patient Awareness in Chronic Kidney Disease: Trends and Predictors 
Archives of internal medicine  2008;168(20):2268-2275.
The impact of recent guidelines for early detection and prevention of chronic kidney disease (CKD) on patient awareness of disease and factors that might be associated with awareness have not been well-described.
Awareness rates were assessed in 2992 adults (≥20 years) with CKD stages 1-4 from a nationally representative, cross-sectional survey (National Health and Nutrition Examination Survey 1999-2004). Awareness of CKD was defined by an answer of yes to: “Have you ever been told you have weak or failing kidneys?” Potential predictors of awareness included demographic, access to care, clinical, and lifestyle factors, which were assessed by standardized interviewer-administered questionnaires and physical exams. We examined independent associations of patient characteristics with awareness in those with CKD stage 3 (N=1314) over 6 years using multivariable logistic regression.
Awareness improved over time in stage 3 only [4.7% (95% CI, 2.6-8.5%), 8.9% (7.1-11.2%), and 9.2% (6.1-13.8%) for 1999-2000, 2001-2002, and 2003-2004, respectively; P = 0.037, adjusted for age, sex, race]. Having proteinuria [OR=3.04 (1.62-5.70)], diabetes [OR=2.19 (1.03-4.64)], and hypertension [OR=2.92 (1.57-5.42)] and being male [OR=2.06 (1.15-3.69)] were all statistically significantly associated with greater awareness among persons with CKD stage 3 after adjustment. CKD awareness increased almost 2-fold for CKD stage 3 over recent years but remains quite low. Persons with risk factors for CKD (proteinuria, diabetes, hypertension, male sex) were more likely to be aware of their stage 3 disease.
Renewed and innovative efforts should be made to increase CKD awareness among patients and providers.
PMCID: PMC2652122  PMID: 19001205
22.  Timing, causes, predictors and prognosis of switching from peritoneal dialysis to hemodialysis: a prospective study 
BMC Nephrology  2009;10:3.
The use of peritoneal dialysis (PD) has declined in the United States over the past decade and technique failure is also reportedly higher in PD compared to hemodialysis (HD), but there are little data in the United States addressing the factors and outcomes associated with switching modalities from PD to HD.
In a prospective cohort study of 262 PD patients enrolled from 28 peritoneal dialysis clinics in 13 U.S. states, we examined potential predictors of switching from PD to HD (including demographics, clinical factors, and laboratory values) and the association of switching with mortality. Cox proportional hazards regression was used to assess relative hazards (RH) of switching and of mortality in PD patients who switched to HD.
Among 262 PD patients, 24.8% switched to HD; with more than 70% switching within the first 2 years. Infectious peritonitis was the leading cause of switching. Patients of black race and with higher body mass index were significantly more likely to switch from PD to HD, RH (95% CI) of 5.01 (1.15–21.8) for black versus white and 1.09 (1.03–1.16) per 1 kg/m2 increase in BMI, respectively. There was no difference in survival between switchers and non-switchers, RH (95% CI) of 0.89 (0.41–1.93).
Switching from PD to HD occurs early and the rate is high, threatening long-term viability of PD programs. Several patient characteristics were associated with the risk of switching. However, there was no survival difference between switchers and non-switchers, reassuring providers and patients that PD technique failure is not necessarily associated with poor prognosis.
PMCID: PMC2649113  PMID: 19200383
23.  Attainment of clinical performance targets and improvement in clinical outcomes and resource use in hemodialysis care: a prospective cohort study 
Clinical performance targets are intended to improve patient outcomes in chronic disease through quality improvement, but evidence of an association between multiple target attainment and patient outcomes in routine clinical practice is often lacking.
In a national prospective cohort study (ESRD Quality, or EQUAL), we examined whether attainment of multiple targets in 668 incident hemodialysis patients from 74 U.S. not-for-profit dialysis clinics was associated with better outcomes. We measured whether the following accepted clinical performance targets were met at 6 months after study enrollment: albumin (≥4.0 g/dl), hemoglobin (≥11 g/dl), calcium-phosphate product (<55 mg2/dl2), dialysis dose (Kt/V≥1.2), and vascular access type (fistula). Outcomes included mortality, hospital admissions, hospital days, and hospital costs.
Attainment of each of the five targets was associated individually with better outcomes; e.g., patients who attained the albumin target had decreased mortality [relative hazard (RH) = 0.55, 95% confidence interval (CI), 0.41–0.75], hospital admissions [incidence rate ratio (IRR) = 0.67, 95% CI, 0.62–0.73], hospital days (IRR = 0.61, 95% CI, 0.58–0.63), and hospital costs (average annual cost reduction = $3,282, P = 0.002), relative to those who did not. Increasing numbers of targets attained were also associated, in a graded fashion, with decreased mortality (P = 0.030), fewer hospital admissions and days (P < 0.001 for both), and lower costs (P = 0.029); these trends remained statistically significant for all outcomes after adjustment (P < 0.001), except cost, which was marginally significant (P = 0.052).
Attainment of more clinical performance targets, regardless of which targets, was strongly associated with decreased mortality, hospital admissions, and resource use in hemodialysis patients.
PMCID: PMC1783649  PMID: 17212829

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