Clinical factors influencing the decision to order red blood cell transfusions for a sample of US dialysis patients
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AIM: To characterize the clinical context for the decision to order red blood cell (RBC) transfusions in dialysis patients. MATERIALS AND METHODS: Retrospective review of medical records from three integrated health systems serving chronic dialysis patients. Subjects were randomly selected from all patients who received at least one transfusion between January 2009 and December 2013. Data abstracted included transfusion setting, prescribing clinician type, patient demographics and hemoglobin (Hb) concentration prior to transfusion, and cataloguing and prioritizing of clinical factors for their contribution to the decision to transfuse. Data from one system were stratified between transfusions before and after the 2011 dialysis payment reform and anemia drug label changes. RESULTS: Charts for 590 patients were reviewed. The primary reason for transfusion was low Hb (51%), medical conditions (22%), symptoms of anemia (18%), surgery-related (6%), and undetermined (3%). In 93% of cases, multiple factors were cited as contributors to the transfusion decision. Mean Hb prior to transfusion was 7.2 g/dL in patients where low Hb was the primary reason for transfusion (range: 4.0 - 9.9 g/dL). CONCLUSIONS: The decision to transfuse dialysis patients is influenced by multiple patient factors and medical conditions, of which low Hb is the main contributor to this decision about half of the time.
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Serum Phosphorus Levels, Race, and Socioeconomic Status in Incident Hemodialysis Patients.

OBJECTIVE: We sought to examine the relationship between race, socioeconomic status, and serum phosphorus levels in patients with end-stage renal disease incident to hemodialysis (HD) at a large, integrated health-care delivery system in Southern California. DESIGN: Retrospective cohort study. SUBJECTS: A total of 5,778 adult patients who initiated HD at our institution between January 1, 2007 and June 30, 2013. MAIN OUTCOME MEASURES: Unadjusted and adjusted time-averaged serum phosphorus levels and actual phosphorus levels over time. Phosphorus levels were also analyzed by repeated measures as a continuous measure and by phosphorus category. Baseline patient covariates included age, self-reported race, gender, cause of end-stage renal disease, and Charlson comorbidity index scores. Education and income level were estimated using geocoded data. RESULTS: A total of 68,372 phosphorus levels were available for 4,862 patients. Estimated annual family income fell below $40,001 in 66.1% of African Americans (AAs) and 62.7% of Hispanics compared with 43.5% of Asians and 43.7% of whites, P < .0001. Educational level fell into the highest category for whites (70.8%) compared with AA (44.8%) or Hispanic (30.5%) patients, P < .0001. Adjusted time-averaged phosphorus levels were lower among Hispanics (4.33 mg/dL, 95% confidence interval [CI] 4.27-4.40) compared with Asian (4.54 mg/dL, 95% CI 4.45-4.64, P < .001) and white patients (4.48 mg/dL, 95% CI 4.43-4.54, P < .001) but similar to AA patients. Asian patients experienced a significant increase in phosphorus levels over time (0.11 mg/dL per year, P < .0001). There were no significant effects of race, time, or race by time interactions in the unadjusted and adjusted categorical analyses of phosphorus levels. CONCLUSIONS: Our findings suggest that serum phosphorus levels are similar among HD patients, irrespective of race or socioeconomic status.

Survival of propensity matched incident peritoneal and hemodialysis patients in a United States health care system.

We sought to compare survival among incident peritoneal dialysis (PD) patients to matched hemodialysis (HD) patients who received pre-dialysis care, including permanent dialysis access placement. Patients starting PD were propensity matched to those starting HD. HD patients who used a central venous catheter during the first 90 days of dialysis were excluded. Stratified Cox proportional hazards models were used to compare patient survival using both intent-to-treat and as-treated analyses. In the intent-to-treat analysis, patients were followed from the date of first dialysis until death and censored at the earliest of the following: renal transplantation, death, renal recovery, loss to follow-up or study end. In the as-treated analysis, patients were also censored at the time of modality change. A total of 1003 matched pairs were obtained from 11,301 incident patients (10,298 HD and 1003 PD). The cumulative hazard ratio for death at one year was 2.38 (95% CI 1.68-3.40) and 2.10 (1.50-2.94) for HD relative to PD patients in the as-treated and intent-to-treat analyses, respectively. The cumulative risk of death, as estimated by the cumulative hazard ratio, favored PD for almost up to 3 years of follow-up in the as-treated analysis and nearly 2 years of follow-up in the intent-to-treat analysis with no differences thereafter. The higher adjusted rate of death observed for HD patients cannot be attributed to initial use of central venous catheters or lack of pre-dialysis care.

Vitamin D deficiency and anemia: a cross-sectional study.

Vitamin D has been suggested to have an effect on erythropoiesis. We sought to evaluate the prevalence of anemia in a population of individuals with vitamin D deficiency compared with those with normal levels in a population of a large integrated healthplan. A cross-sectional analysis in the period 1 January 2004 through 31 December 2006 of subjects with documented concurrent levels of 25-hydroxyvitamin D and hemoglobin were evaluated. Vitamin D deficiency was defined as <30 ng/mL and anemia was defined as a hemoglobin <11 g/dL. A total of 554 subjects were included in the analysis. Anemia was present in 49% of 25-hydroxyvitamin D-deficient subjects compared with 36% with normal 25-hydroxyvitamin D levels (p < 0.01). Odds ratio for anemia in subjects with 25-hydroxyvitamin D deficiency using logistic regressions and controlling for age, gender, and chronic kidney disease was 1.9 (95% CI 1.3-2.7). 25-hydroxyvitamin D-deficient subjects had a lower mean Hb (11.0 vs. 11.7; p = 0.12 ) and a higher prevalence of erythrocyte stimulating agent use (47% vs. 24%; p < 0.05). This study demonstrates an association of vitamin D deficiency and a greater risk of anemia, lower mean hemoglobin, and higher usage of erythrocyte-stimulating agents. Future randomized studies are warranted to examine whether vitamin D directly affects erythropoiesis.

Hospitalization rates in daily home hemodialysis versus peritoneal dialysis patients in the United States.

BACKGROUND: Daily hemodialysis (DHD) is associated with improvements in hypertension, left ventricular hypertrophy, mineral metabolism, nutrition, and quality of life, but efficacy is uncertain because of potential selection bias. To reduce the influence of selection bias, we sought to compare hospital admissions for our population of DHD patients with peritoneal dialysis (PD) patients who initiated training during the same period. We also compared our hospital data with the US Renal Data Service database. STUDY DESIGN: Prospective nonrandomized cohort study. SETTING & PARTICIPANTS: 22 (16 male) DHD and 64 (33 male) PD patients who initiated training between March 2003 and September 2007 at our center and remained in our program for at least 6 months. PREDICTORS: Dialysis modality (DHD or PD). OUTCOMES: Number of hospital admissions and length of stay. RESULTS: Median age at initiation of training was 52 years (range, 33 to 76 years) for DHD patients versus 54 years (range, 21 to 82 years) for PD patients (P = 0.5), and median vintage was 23 months (range, 0 to 145 months) for DHD patients versus 0 month (range, 0 to 244 months) for PD patients (P < 0.001). Fifty percent of DHD and 56% of PD patients had a diagnosis of diabetes mellitus (P = 0.8). We observed 27 DHD and 82 PD admissions (0.68 and 0.76 admissions/patient-year, respectively) during the study period (P = 0.5). We also observed 130 DHD and 605 PD hospital days (3.3 and 5.6 days/patient-year, respectively; P < 0.001). LIMITATIONS: Patients were not randomly assigned between the study group and control group; study group was small. CONCLUSIONS: Our study suggests that despite similar patient demographics, patients treated with DHD spend fewer days in the hospital than PD patients in the United States. Although selection bias could partially explain our lower hospitalization rate, other factors, including improvements in blood pressure control, nutrition, and fewer fluctuations in dry weight, probably contributed to the stability of our patients.

Prevalence of nondiabetic renal disease in diabetic patients.

BACKGROUND: Diabetic nephropathy is the leading cause of end-stage renal disease in the USA, yet most patients with type 2 diabetes mellitus are not formally evaluated with a renal biopsy. Our aim was to evaluate the prevalence of nondiabetic renal disease (NDRD) in patients with type 2 diabetes mellitus to determine common clinical indicators suggestive of NDRD. METHODS: A retrospective analysis was performed on biopsy reports of patients who had undergone native renal biopsy between January 1, 1995, and December 31, 2005. RESULTS: After exclusion of 57 patients, 233 patients with DM2 were included in our analysis. Mean age at the time of biopsy was 58.1 +/- 13.7 years, and 53.0% of the study population were male. There were 124 cases (53.2%) with a pathologic diagnosis of NDRD, 64 (27.5%) with pure diabetic glomerulosclerosis (DGS) and 45 (19.3%) with concurrent NDRD and DGS (CD). Patients with NDRD tended to be younger than those with DGS and had significantly less associated diabetic retinopathy. Focal segmental glomerulosclerosis was the most common lesion found in patients with NDRD and accounted for 21.0% of all NDRD, followed by minimal-change disease (15.3%). IgA nephropathy (15.6%) and membranous glomerulonephritis (13.3%) were the most prevalent lesions found in patients with CD. CONCLUSIONS: The high prevalence of NDRD found in our population underscores the need for clinicians to consider renal biopsy in diabetic patients with an atypical clinical course, since additional disease-specific therapies may be helpful for this subset of the population.

Daily home hemodialysis at a health maintenance organization: three-year experience.

Daily home hemodialysis (DHD), 5 to 7 short-duration hemodialysis treatments per week, promotes self-care and has beneficial effects on a number of clinical outcomes including blood pressure and volume control, electrolyte balance, uremic symptoms and sequelae, and quality of life. We sought to demonstrate that DHD is feasible and confers clinical benefits that permit savings in overall healthcare costs despite expenditures on program infrastructure and supplies. We examined the following outcomes monthly for all patients: laboratory values, dialysis adequacy, hospital admission records, surgical and interventional radiology records, and prescription medication usage. Twelve patients completed training in our home hemodialysis unit between April 2003 and April 2006. The mean age at the time of training was 58 years and mean vintage was 62 months. The mean treatment time was 147 min, and the mean number of treatments performed was 5.3 per week. When 1 patient with morbid obesity was excluded due to intentional weight loss, the mean dry weight at initiation of training was 71.9+/-12.4 kg and increased to 74.3+/-12.4 kg by the end of the study (p=0.66). The mean albumin increased from a baseline of 3.9+/-0.3 to 4.3+/-1.1 gm/dL during DHD (p=0.0015). The mean serum phosphorus levels were 5.4+/-1.4 mg/dL. Phosphate binder usage increased from a mean baseline of 2.6+/-1.4 to 4.2+/-2.6 tablets per meal during DHD (p=0.08). The mean delivered single pool Kt/V was 0.87 per treatment. During the 234 months studied, there were 11 hospital admissions (0.56 admissions per patient per year), with a mean length of stay of 3.7 days. Our results demonstrate that DHD improves nutritional status and decreases hospital admissions for dialysis-dependent patients.

Comparison and interpretation of urinalysis performed by a nephrologist versus a hospital-based clinical laboratory.

BACKGROUND: Urinalysis (UA) is considered the most important laboratory test in evaluating patients with kidney disease. Anecdotally, we have observed differences between results of UA performed by nephrologists compared with those performed by certified medical technologists or clinical laboratory scientists that could affect a clinician's diagnosis. Whether there are differences between UA performed by the clinical laboratory and that performed by a nephrologist was determined, and accuracy of diagnosis based on interpretation of the UA was compared. METHODS: Urine samples were obtained from 26 patients with acute renal failure (ARF). An aliquot of urine was sent to the clinical laboratory for UA. Nephrologist A, blinded to the patient's clinical information, performed a UA on the other aliquot of urine, generated a report, and assigned the most likely diagnosis for ARF based on UA findings. Nephrologist B, also blinded to the clinical information, reviewed nephrologist A's UA reports and assigned a diagnosis for ARF to each report. Nephrologists A and B both assigned a diagnosis (or diagnoses) for the ARF based on laboratory UA results. These 4 sets of diagnoses were compared with those assigned by the consult nephrologists. RESULTS: Nephrologist A correctly diagnosed the cause of ARF in 24 of 26 samples (92.3% success rate) based on his performance of the UA. Diagnoses by nephrologists A and B, based on their review of the clinical laboratory UA report, were correct in only 23.1% and 19.2% of the samples, respectively. Accuracy of diagnosis for nephrologist B improved to 69.3% when she reviewed UA reports from nephrologist A. Nephrologist A's review of urine sediment was significantly more accurate than interpretations by nephrologist A or B of clinical laboratory reports (sign test, P < 0.001). Nephrologist A reported a greater number of renal tubular epithelial (RTE) cells (P < 0.0001), granular casts (P = 0.0017), hyaline casts (P = 0.0233), RTE casts (P = 0.0008), and dysmorphic red blood cells. The laboratory noted a greater number of squamous cells (P = 0.0034). CONCLUSION: A nephrologist is more likely to recognize the presence of RTE cells, granular casts, RTE casts, and dysmorphic red blood cells in urine. The laboratory may be reporting RTE cells incorrectly as squamous epithelial cells. Nephrologist-performed UA is superior to laboratory-performed UA in determining the correct diagnosis.

Predictors of peritonitis, hospital days, and technique survival for peritoneal dialysis patients in a managed care setting.

INTRODUCTION: Many clinicians perceive that peritoneal dialysis (PD) should be reserved for younger, healthier, more affluent patients. Our aim was to examine outcomes for PD patients in a managed care setting and to identify predictors of adverse outcomes. METHODS: We identified all patients who initiated PD at our institution between 1 January 2001 and 31 December 2010. Predictor variables studied included age, sex, race, PD modality, cause of end-stage renal disease (ESRD), dialysis vintage, Charlson comorbidity index (CCI) score, education, and income level. Poisson models were used to determine the relative risk (RR) of peritonitis and the number of hospital days per patient-year. The log-rank test was used to compare technique survival by patient strata. RESULTS: Among the 1378 patients who met the inclusion criteria, only female sex [RR: 0.85; 95% confidence interval (CI): 0.74 to 0.98; p = 0.02] and higher education (RR: 0.77; 95% CI: 0.60 to 0.98; p = 0.04) were associated with peritonitis. For hospital days, dialysis vintage (RR: 1.11; 95% CI: 1.04 to 1.18; p = 0.002), CCI score (RR: 1.06; 95% CI: 1.02 to 1.20; p = 0.002), and cause of ESRD (RR for glomerulonephritis: 0.59; 95% CI: 0.43 to 0.80; p = 0.0006; and RR for hypertension: 0.69; 95% CI: 0.55 to 0.88; p = 0.002) were associated with 1 extra hospital day per patient-year. The 2-year technique survival was 61% for patients who experienced at least 1 episode of peritonitis and 72% for those experiencing no peritonitis (p = 0.0001). Baseline patient age, primary cause of ESRD, and PD modality were the only other variables associated with technique survival in the study. CONCLUSIONS: Neither race nor socio-economic status predicted technique survival or hospital days in our study. Female sex and higher education were the only two variables studied that had an association with peritonitis.

Comparing cardiac surgery in peritoneal dialysis and hemodialysis patients: perioperative outcomes and two-year survival.

BACKGROUND: We sought to compare perioperative outcomes and 2-year survival in a cohort of peritoneal dialysis (PD) patients compared with matched hemodialysis (HD) patients who underwent cardiothoracic surgery at our institution. METHODS: We obtained a list of all dialysis-dependent patients who underwent cardiac surgery (coronary artery bypass grafting, valve replacement, or both) at our center between 1994 and 2008. All patients undergoing PD at the time of surgery were included in our analysis. Two HD patients matched for age, diabetes status, and Charleston comorbidity score were obtained for each PD patient. RESULTS: The analysis included 36 PD patients and 72 HD patients. Mean age, sex, diabetes status, cardiac unit stay, hospital stay, and operative mortality did not differ by dialysis modality. The incidence of 1 or more postoperative complications (infection, prolonged intubation, death) was higher for HD patients (50% vs. 28% for PD patients, p = 0.046). After surgery, 2 PD patients required conversion to HD. The 2-year survival was 69% for PD patients and 66% for HD patients (p = 0.73). CONCLUSIONS: Our findings suggest that, compared with HD patients, PD patients who require cardiac surgery do not experience more early complications or a lesser 2-year survival and that 2-year survival for dialysis patients after cardiac surgery is acceptable.

Vitamin D supplementation and recombinant human erythropoietin utilization in vitamin D-deficient hemodialysis patients.

INTRODUCTION: We sought to examine the impact of ergocalciferol (ERGO) on recombinant human erythropoietin (EPO) use in a cohort of 25-OH vitamin D (25-D)-deficient hemodialysis (HD) patients. METHODS: Baseline 25-D levels were obtained for all patients who received HD >6 months in our unit. Patients with levels between 10 and 30 ng/mL received ERGO 50,000 IU x 4 doses and patients with levels <10 ng/mL received 50,000 IU x 6 doses over a 4-month period. Monthly dose of EPO was recorded at baseline and after ERGO supplementation. RESULTS: Baseline 25-D levels were <30 ng/mL in 89% of tested patients. Eighty-one patients were included in this study. Mean baseline 25-D level was 15.3 ± 7.1 ng/mL and increased to 28.5 ± 8.6 ng/mL after ERGO (p<0.0001), and median baseline EPO dose was 21,933 U/month (interquartile range [IQR] 13,867-35,967) and decreased to 18,400 U/month (IQR 11,050-33,000) after ERGO (p=0.17). Forty-six patients (57%) required less EPO after ERGO compared with baseline: 15,450 U/month (IQR 10,056-23,575) vs. 26,242 U/month (IQR 15,717-40,167), respectively (p<0.0001). Thirty-five patients (43%) required a higher dose of EPO after ERGO, 26,350 U/month (IQR 15,875-46,075) vs. 17,667 U/month (IQR 12,021-23,392), respectively (p=0.016). Mean age, sex, vintage, diabetes status, race and 25-D levels did not differ in these 2 groups of patients, either at baseline or after ERGO. Monthly hemoglobin, iron saturation, albumin, intact parathyroid hormone, calcium and phosphorus were unchanged after ERGO in these 2 groups. CONCLUSIONS: ERGO use in 25-D-deficient HD patients may lessen the need for EPO. We recommend more aggressive supplementation with ERGO in future studies to achieve levels >30 ng/mL.

Sleep apnea in early and advanced chronic kidney disease: Kaiser Permanente Southern California cohort.

BACKGROUND: Sleep apnea (SA) has been reported to be highly prevalent in the dialysis population. The reported rates of SA in dialysis are severalfold greater than the 2 to 4% estimated in the general population. This study sought to determine whether an association exists between SA and early stages of chronic kidney disease (CKD) where SA may represent an important comorbidity and potential risk factor in kidney disease. METHODS: Cross-sectional study of adults from an integrated health plan with documented serum creatinine levels in the period January 1, 2002, through December 31, 2004. SA diagnosis determined by International Classification of Diseases, ninth revision, coding for SA and Current Procedural Terminology coding for positive airway pressure devices. Kidney function was determined by the estimated glomerular filtration rate (eGFR). Logistic was regression used to estimate the relative risk for SA. RESULTS: The overall prevalence of SA was 2.5% in the study population that included subjects with normal renal function and those with CKD. The odds ratios (ORs) for SA by eGFRs of 75 to 89, 60 to 74, 45 to 59, 30 to 44, and 15 to 29 mL/min per 1.73 m(2), respectively, compared to normal kidney function, after adjustment for age, sex, and number of visits, were as follows: 1.22 (95% confidence interval [CI], 1.18 to 1.25); 1.32 (95% CI, 1.27 to 1.37); 1.42 (95% CI, 1.35 to 1.50); 1.37 (95% CI, 1.25 to 1.50); and 1.32 (95% CI, 1.13 to 1.55). The increased ORs for eGFRs > 45 mL/min per 1.73 m(2) were sustained even after controlling for diabetes, heart failure, and hypertension. CONCLUSION: This study demonstrated an increased risk of SA in patients with early CKD. Further evidence of a causal relationship should be sought in the hope that the detection and management of SA may improve the course of CKD.