Search PubMed⌕ Search

Biomedical subjects

Allan J Collins

Publications and source records attributed to Allan J Collins.

At least 37 records · Page 2Linked to original sources

Projecting the number of patients with end-stage renal disease in the United States to the year 2015.

The size of the prevalent ESRD population in the United States increased dramatically during the 1990s, from 196,000 in 1991 to 382,000 in 2000. Incidence also increased considerably during the same period, from 53,000 to 93,000 per year. If previous trends in ESRD incidence and prevalence continue, then current levels of health care resources that are devoted to the care of these patients will eventually be unable to meet the demand. This study discusses a Markov model developed to predict ESRD incidence, prevalence, and mortality to the year 2015 and incorporating expected changes in age/race distributions, diabetes prevalence, ESRD incidence, and probability of death. The model predicted that by 2015 there will be 136,166 incident ESRD patients per year (lower/upper limits 110,989 to 164,550), 712,290 prevalent patients (595,046 to 842,761), and 107,760 ESRD deaths annually (96,068 to 118,220). Incidence and prevalence counts are expected to increase by 44 and 85%, respectively, from 2000 to 2015 and incidence and prevalence rates per million population by 32 and 70%, respectively. The financial and human resources that will be needed to care for these patients in 2015 will be considerably greater than in 2005.

Age Distribution↗

Glycosylated hemoglobin and mortality in patients with nondiabetic chronic kidney disease.

In the general population, hyperglycemia in the absence of diabetes may be associated with increased risk for mortality. Hyperglycemia is prevalent in chronic kidney disease; however, the relationship between glycosylated hemoglobin (HbA(1c)) as a marker of chronic hyperglycemia and outcomes has not been studied in nondiabetic chronic kidney disease. HbA(1c) was measured at baseline in the randomized cohort of the Modification of Diet in Renal Disease Study (n = 840). Participants with diabetes (n = 43), fasting glucose levels >126 mg/dl (n = 20), or missing HbA(1c) levels (n = 9) were excluded. Survival status until December 2000 was obtained from the National Death Index. Death was classified as cardiovascular (CVD) when the primary cause was International Classification of Disease, Ninth Revision codes 390 to 459. Cox models were performed to assess the relationship of HbA(1c) with all-cause and CVD mortality. Mean (SD) age was 52 (12) years, and mean (SD) GFR was 32 (12) ml/min per 1.73 m(2). Eighty-six percent of participants were white, and 61% were male. Mean (SD) HbA(1c) was 5.6% (0.5). A total of 169 (22%) patients died, 96 (13%) from CVD. After adjustment for randomization assignments and demographic, CVD, and kidney disease factors, HbA(1c) was a predictor of all-cause mortality (hazard ratio per 1% increase 1.73; 95% confidence interval 1.24 to 2.41; P = 0.001). There was a trend toward statistical significance in the relationship between HbA(1c) and CVD mortality (hazard ratio per 1% increase 1.53; 95% confidence interval 0.96 to 2.43; P = 0.07). HbA(1c) is associated with increased mortality in nondiabetic kidney disease. Hyperglycemia may be a potential therapeutic target and HbA(1c) may be important as a risk stratification tool in this high-risk population.

Adult↗

General medical care among patients with chronic kidney disease: opportunities for improving outcomes.

Suboptimal health care during advancing chronic kidney disease (CKD) may result in greater morbidity and cost once dialysis is started and may preclude future transplantation. Medicare data were examined for the prevalence of selected general health, diabetes, and CKD interventions in a national cohort of patients in the 2 yr before dialysis initiation and compared with a contemporaneous non-CKD cohort. A total of 24,778 individuals who were aged > or =67 yr composed the CKD cohort, and 1,046,136 individuals who were aged > or =67 yr did not have CKD. Among patients with diabetes and CKD, fewer than two thirds had claims for eye examinations, 75% for HbA(1C) testing, and 68% for lipid testing, with similar proportions in the non-CKD cohort. Among those without diabetes, 47 and 54% of the CKD and non-CKD cohorts, respectively, had claims for lipid testing. Fewer than 50 and 15% had claims for influenza and pneumococcal vaccination, respectively, with slightly lower proportions among patients with CKD. Claims for cancer tests were found for 14 to 41% and 29 to 52% of individuals with and without CKD, respectively, depending on the type of cancer. A greater proportion of patients with diabetes tended to have claims for tests in both cohorts. In the CKD cohort, claims for anemia testing and parathyroid hormone levels were available in fewer than 50 and 15%, respectively, and claims for permanent vascular access were found for only 30% of hemodialysis patients. This study provides further evidence that patients with CKD may not be receiving general health and CKD care according to current recommendations.

Aged↗

Health status and quality of life reported by incident patients after 1 year on haemodialysis or peritoneal dialysis.

BACKGROUND: It has been suggested that there are no large differences in the quality of life of incident patients starting on haemodialysis (HD) and peritoneal dialysis (PD), but few studies have addressed this issue. METHODS: Association of modality with incident patients' health status and quality of life scores was investigated with propensity score (PS) analysis and also with traditional multivariable regression analyses. We compared patient reported health status and quality of life scores after 1 year of therapy in 455 HD and 413 PD patients who participated in a national study, stayed on the same modality and had complete socio-demographic and clinical information needed to create a PS indicating their expected probability of starting on PD. RESULTS: One year scores on the majority of health status and quality of life measures were not significantly different for HD and PD patients within propensity-matched quintiles. PD patients' scores were higher than HD patients' scores on effects of kidney disease, burden of kidney disease, staff encouragement and satisfaction with care in some quintiles, and traditional regression analyses confirmed that dialysis modality was associated with patients' scores on these variables. CONCLUSIONS: This study provides support for making the choice of PD more widely available as an option to patients initiating chronic dialysis therapy. Patient lifestyle opportunities associated with use of PD, a home-based and self-care therapy, may also apply to home-based HD or in-centre self-care HD. Patients' expectations regarding treatment and their attitudes toward management of their health may interact with treatment modality to shape patient-reported experience on dialysis; this is an important focus for future studies.

Adult↗

Calcium, phosphorus, parathyroid hormone, and cardiovascular disease in hemodialysis patients: the USRDS waves 1, 3, and 4 study.

Animal studies suggest that calcium-phosphorus homeostatic abnormalities cause cardiovascular disease in uremia; few observational studies in humans have explored this. Associations in the retrospective United States Renal Data System Waves 1, 3, and 4 Study of 14,829 patients who were on hemodialysis on December 31, 1993, were examined. Mean age and duration of renal replacement therapy were 60.0 and 3.2 yr, respectively; 40.7% had diabetes. Quintiles (Q(1) to Q(5)) of (albumin-adjusted) calcium were </=8.7, 8.8 to 9.2, 9.3 to 9.6, 9.7 to 10.2, and >10.2 mg/dl; phosphorus, </=4.4, 4.5 to 5.3, 5.4 to 6.3, 6.4 to 7.5, and >7.5 mg/dl; calcium-phosphorus product, </=40.9, 41.0 to 50.1, 50.2 to 59.2, 59.3 to 71.0, and >71.0 mg(2)/dl(2); and parathyroid hormone (PTH), </=37, 38 to 99, 100 to 210, 211 to 480, and >480 pg/ml. Higher calcium levels were associated with fatal or nonfatal cardiovascular events (adjusted hazards ratio, 1.08 for Q(5), versus Q(1)) and all-cause mortality (Q(2), 1.07; Q(4), 1.11; Q(5), 1.14). Phosphorus levels were associated with cardiovascular events (Q(2), 1.06; Q(3), 1.13; Q(4), 1.14; Q(5), 1.25) and mortality (Q(4), 1.10; Q(5), 1.19), calcium-phosphorus product was associated with cardiovascular events (Q(3), 1.09; Q(4), 1.14; Q(5), 1.24) and mortality (Q(4), 1.09; Q(5), 1.19), and PTH levels were associated with cardiovascular events (Q(5), 1.12) and mortality (Q(5), 1.17). Despite limitations (including retrospective design; noncurrent study era; and lack of serial calcium, phosphorus, and PTH measurements), this study suggests that disorders of calcium homeostasis are associated with fatal and nonfatal cardiovascular events and all-cause mortality in hemodialysis patients.

Adult↗

The effect of a lower target blood pressure on the progression of kidney disease: long-term follow-up of the modification of diet in renal disease study.

BACKGROUND: Hypertension is a risk factor for progression of chronic kidney disease. The optimal blood pressure to slow progression is unknown. OBJECTIVE: To evaluate the effects of a low target blood pressure on kidney failure and all-cause mortality. DESIGN: Long-term follow-up of the Modification of Diet in Renal Disease Study, a randomized, controlled trial conducted from 1989 to 1993. SETTING: 15 outpatient nephrology practices. PARTICIPANTS: 840 persons with predominantly nondiabetic kidney disease and a glomerular filtration rate of 13 to 55 mL/min per 1.73 m2. INTERVENTION: A low target blood pressure (mean arterial pressure < 92 mm Hg) or a usual target blood pressure (mean arterial pressure < 107 mm Hg). MEASUREMENTS: After the randomized trial was completed, kidney failure (defined as initiation of dialysis or kidney transplantation) and a composite outcome of kidney failure or all-cause mortality were ascertained through 31 December 2000. RESULTS: Kidney failure occurred in 554 participants (66%), and the composite outcome occurred in 624 participants (74%). After Cox proportional hazards modeling and intention-to-treat analysis, the adjusted hazard ratios were 0.68 (95% CI, 0.57 to 0.82; P < 0.001) for kidney failure and 0.77 (CI, 0.65 to 0.91; P = 0.0024) for the composite outcome in the low target blood pressure group compared with the usual target blood pressure group. Evidence was insufficient to conclude that the benefit of a low target blood pressure differed according to the cause of kidney disease, baseline glomerular filtration rate, or degree of proteinuria. LIMITATIONS: The exact mechanism underlying the benefit of a low target blood pressure is unknown. CONCLUSIONS: Assignment to a low target blood pressure slowed the progression of nondiabetic kidney disease in patients with a moderately to severely decreased glomerular filtration rate.

Adolescent↗

Angiotensin-converting enzyme inhibitor as a risk factor for the development of anemia, and the impact of incident anemia on mortality in patients with left ventricular dysfunction.

OBJECTIVES: We aimed to investigate the impact of angiotensin-converting enzyme inhibitors (ACEIs) on hematocrit values in those with heart failure, and the relationship between incident anemia and mortality. BACKGROUND: Prevalent anemia is an independent risk factor for morbidity and mortality in those with heart failure. Studies in patients with polycythemia have demonstrated that ACEIs are effective in lowering hematocrit values. METHODS: We used the Studies Of Left Ventricular Dysfunction (SOLVD) database to compare the odds of developing new anemia at one year in patients who were not anemic at entry and who were randomized to enalapril or placebo. Cox proportional hazards models were utilized to determine the impact of incident and prevalent anemia on subsequent mortality. RESULTS: Enalapril increased the odds of incident anemia (hematocrit < or =39% in men or < or =36% in women) at one year by 48% (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.20 to 1.82) in unadjusted and 56% (OR 1.56, 95% CI 1.26 to 1.93) in adjusted models. With multivariate analysis, prevalent anemia at randomization was associated with a 44% (hazard ratio [HR] 1.44, 95% CI 1.31 to 1.66) increase in all-cause mortality, whereas incident anemia after randomization was associated with a 108% increase (HR 2.08, 95% CI 1.82 to 2.38). After adjusting for incident and prevalent anemia, use of enalapril was associated with a survival benefit. CONCLUSIONS: Enalapril was associated with increased odds of developing anemia at one year. Those with periods of time with incident anemia had the poorest survival, followed by those with prevalent anemia, then those without anemia. Enalapril was protective of overall mortality after adjusting for incident anemia and in those with prevalent anemia.

Aged↗

Anemia and cardiovascular disease, hospitalization, end stage renal disease, and death in older patients with chronic kidney disease.

BACKGROUND: Large observational studies examining the association between anemia and "hard" clinical outcomes are rare in patients with chronic kidney disease (CKD). METHODS: We used the General Medicare 5% Denominator Files to identify patients aged 67 years or more with CKD on December 31, 1999. Outcomes in the ensuing 2 years were compared in patients with and those without anemia (entry period, 1998-1999; follow-up period, 2000-2001). RESULTS: Of 41,522 CKD patients identified, 49.0% had claims of anemia diagnosis. The factors associated (p< 0.0001) with anemia included older age, female gender, black race, and all 10 comorbid conditions studied; adjusted odds ratios (ORs) exceeded 1.5 for age 80 years old or older (OR, 1.54 compared to <70 years), for black race (OR, 1.52), and for co-existing diagnoses of congestive heart failure (OR, 1.64), gastrointestinal bleeding (OR, 3.65), and liver disease (OR, 2.16). During the follow-up period, outcome event rates (expressed per 1000 patient-years) were as follows: renal replacement therapy, 23.5; death, 186.4; congestive heart failure, 390.0; atherosclerotic vascular disease, 410.5; and first hospitalization, 552.6. Using proportional hazards modeling, the presence of anemia was associated (p < 0.0001) with the following adjusted hazards ratios: atherosclerotic vascular disease, 1.09; congestive heart failure, 1.14; renal replacement therapy, 2.61 and death, 1.40. CONCLUSION: A diagnosis of anemia is present in nearly half of all patients with CKD, aged 67 years or more, a group at very high risk of cardiovascular disease, hospitalization, end-stage renal disease, and death. Anemia is associated with each of these events.

Aged↗

Anemia and new-onset congestive heart failure in the general Medicare population.

BACKGROUND: Anemia is associated with disease severity and prognosis for patients with congestive heart failure (CHF). It is unknown whether anemia is associated with the development of new-onset CHF in the elderly. METHODS AND RESULTS: This retrospective longitudinal cohort study used the Medicare 5% database. In the incident analysis, the study sample comprised subjects without CHF in 1999 (n = 1,063,495); the main exposure variable evaluated was the presence or absence of anemia in 1999; and the primary study outcome was the occurrence of new-onset CHF. The prevalence of chronic anemia and CHF in 1999 was 5.0% and 9.9%, respectively. The incidence of new-onset CHF in 2000 in those with and those without anemia in 1999 was 12.3% and 5.9%, respectively, corresponding to an adjusted hazard ratio of 1.29 ( P < .001), a value intermediate between the hazard ratios of 1.13 ( P < .001), and 1.76 ( P < .001) associated with hypertension and atherosclerotic heart disease, respectively. Anemia also was associated with death in the year after new-onset CHF (adjusted hazard ratio, 1.28; P < .001). CONCLUSION: Anemia in the Medicare population is associated with the diagnosis and prognosis of new-onset CHF.

Age Factors↗

Intractable anemia among hemodialysis patients: a sign of suboptimal management or a marker of disease?

BACKGROUND: Most incident hemodialysis (HD) patients who initiate dialysis therapy with anemia usually can achieve a hemoglobin (Hb) level of 11 g/dL or greater (> or =110 g/L) within a few months of the initiation of recombinant human erythropoietin (EPO) therapy. However, patients unable to achieve this level may be at greater risk for adverse outcomes. Whether intractable anemia is a modifiable problem or a marker for other conditions is unclear. This question was addressed in a cohort of 130,544 incident HD patients from 1996 to 2000 who were administered EPO regularly. METHODS: Medicare claims data were used to determine demographic characteristics, comorbidities, hospitalizations, and related events. Patients who did not achieve an Hb level of 11 g/dL or greater (> or =110 g/L; n = 19,096; 14.6%) during months 4 to 9 after dialysis therapy initiation were compared with those who did. RESULTS: Patients unable to achieve an Hb level of 11 g/dL (110 g/L) were younger and more often of nonwhite race. In addition, these patients had more comorbid conditions; experienced more hospitalizations with longer stays, more infectious hospitalizations, and more catheter insertions; and were administered more blood transfusions. EPO was administered in higher and increasing doses during the years of study among patients with intractable anemia compared with those with an Hb level of 11 g/dL or greater (> or =110 g/L), likely denoting increasing attempts to correct anemia over the years. CONCLUSION: It is apparent that incident HD patients unable to achieve an Hb level of 11 g/dL or greater (> or =110 g/L) have a greater disease burden. The independent association of intractable anemia with such future outcomes as cardiovascular events and hospitalizations remains to be determined.

Adult↗

A comparison of peritonitis rates from the United States Renal Data System database: CAPD versus continuous cycling peritoneal dialysis patients.

BACKGROUND: Previous comparisons of peritonitis rates between continuous ambulatory peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD) have produced varying results. METHODS: Using United States Renal Data System data, the authors evaluated peritonitis rates in 1994 through 1997 incident CAPD (n = 9,190) and CCPD (n = 2,785) Medicare patients. Patients were characterized during a 6-month entry period (months 4 through 9) and followed for a maximum of 2 years (months 10 through 33). Medicare claims data provided the date of the first peritonitis episode during the follow-up period. The time to first peritonitis after 9 months of PD was compared by the log-rank test, and then by Cox regression with adjustment for peritoneal dialysis modality, age, sex, race, primary end-stage renal disease (ESRD) diagnosis, number of entry-period hospital days, peritonitis during the entry period, hematocrit value, and congestive heart failure. RESULTS: For CAPD and CCPD, the adjusted average months to first peritonitis after 9 months of PD were 17.1 and 16.1, respectively. The probabilities of remaining without a peritonitis episode after 1 year of follow-up were 0.53 and 0.50, respectively ( P = 0.008). The risk of peritonitis was lower for CAPD than for CCPD (relative risk, 0.939; 95% confidence interval, 0.883 to 0.998). Other significant risk factors included age or=36% had lower risk of peritonitis. CONCLUSION: Compared with CCPD, CAPD is associated with a slightly but significantly lower risk for development of a first peritonitis episode after 9 months of peritoneal dialysis therapy.

Adolescent↗

Association of heart disease with diabetes and hypertension in patients with ESRD.

BACKGROUND: No published study has reported the combined effect of diabetes and hypertension on heart disease in patients with renal failure. We determined this effect by using data for all US adults who started renal replacement therapy from 1995 to 1999. METHODS: Data for patient characteristics, diabetes, hypertension, and heart disease were collected from the Medical Evidence Report, on which 6 cardiac conditions were recorded: congestive heart failure, ischemic heart disease, myocardial infarction, cardiac arrest, cardiac arrhythmia, and pericarditis. On the basis of diabetic-hypertensive status, we categorized patients into 4 groups: diabetes only, hypertension only, both diabetes and hypertension, and neither diabetes nor hypertension. Adjusting for age, sex, race-ethnicity, and incidence year with logistic regression, we estimated the likelihood of heart disease according to diabetic-hypertensive status. RESULTS: Of 373,539 patients, 49.8% had diabetes and 75.8% had hypertension; 11.4% had diabetes only, 37.4% had hypertension only, 38.4% had both diabetes and hypertension, and 12.8% had neither diabetes nor hypertension. Approximately 44% of patients (n = 163,570) had at least 1 condition, 19.4% had at least 2 conditions, and 6.5% had at least 3 of the 6 cardiac conditions. Logistic regression indicated that patients with diabetes only and hypertension only were 3.1 and 2.8 times more likely ( P < 0.0001) to have heart disease than those without diabetes and hypertension, respectively. Patients with both diabetes and hypertension were 5.9, 5.0, and 4.8 times more likely (P < 0.0001) to have at least 1, at least 2, and at least 3 cardiac conditions than those with neither diabetes nor hypertension, respectively. CONCLUSION: Patients with renal failure with both diabetes and hypertension are more likely to have heart disease than those with diabetes only and hypertension only.

Adolescent↗

Epoetin alfa use in patients with ESRD: an analysis of recent US prescribing patterns and hemoglobin outcomes.

BACKGROUND: It is unknown to what degree physicians adjust erythropoietin doses to achieve hemoglobin levels (11.0 to 12.0 g/dL [110 to 120 g/L]) recommended by the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-K/DOQI) for patients with end-stage renal disease receiving hemodialysis. Our objective is to examine epoetin alfa prescribing patterns for achieving the target hemoglobin level range in this population. METHODS: Monthly hemoglobin levels and epoetin alfa doses from 2 large databases were retrospectively analyzed. One data set comprised 31,267 patients from the Fresenius Medical Care-North America (FMC-NA) database, and the other comprised 128,761 patients based on claims for Medicare services. RESULTS: Longitudinal evaluation of the FMC-NA data set showed that hemoglobin levels in patients administered epoetin alfa cycled in and out of the NKF-K/DOQI hemoglobin target range, and doses were decreased in 98.8% of patients with persistent hemoglobin levels greater than 12.0 g/dL (> 120 g/L). Hemoglobin levels in patients from the Medicare data set that initially were outside the target range migrated into the range with epoetin alfa dose titration. FMC-NA patients with a 3-month average hemoglobin level less than 11.0 g/dL (< 110 g/L) were administered significantly greater epoetin alfa doses than those with average hemoglobin levels greater than 12.0 g/dL (> 120 g/L; 21,838 versus 13,503 U/wk; P < 0.0001). Less than 0.4% of patients administered epoetin alfa were persistently anemic (hemoglobin < 11.0 g/dL [< 110 g/L]) and were administered persistently high doses (> 30,000 U/wk), but failed to respond with a 0.5-g/dL or greater (> or = 5-g/L) increase in hemoglobin levels. CONCLUSION: In these analyses, few hemodialysis patients experienced persistent anemia while being administered high epoetin alfa doses. Physicians appeared to appropriately adjust doses to achieve hemoglobin levels recommended by the NKF-K/DOQI guidelines.

Anemia↗

Trends in intravenous iron use among dialysis patients in the United States (1994-2002).

BACKGROUND: Two new intravenous (IV) iron products, ferric gluconate and iron sucrose, recently were approved for use in the United States. We report trends in IV iron use in both incident (1994 to 2001) and prevalent (1994 to 2002) Medicare US dialysis patients. METHODS: Included patients had Medicare as a primary payer. Recombinant human erythropoietin doses, IV iron use, and hemoglobin data were obtained from Medicare outpatient files. The most recent cohorts included 241,770 prevalent hemodialysis (HD) patients in 2002 and 11,744 incident HD patients in 2001. RESULTS: For incident HD patients in the first 9 months of dialysis therapy, the percentage of patients administered IV iron increased sharply between 1994 and 1997 and then increased gradually between 1997 and 2001. In 2002, a total of 84.4% of HD and 19.3% of peritoneal dialysis (PD) patients were administered IV iron. Ferric gluconate use increased slowly in 2000, increased from 5.7% to 18.6% from December 2000 to January 2001, increased to 29.8% in April 2002, and was 23.3% in December 2002. Iron sucrose use increased to 26% by December 2002. The absolute monthly percentage of HD patients administered IV iron dextran decreased from 49.6% in January 2000 to 3.6% in December 2002. CONCLUSION: In US patients with end-stage renal disease, IV iron use has increased, although slowly, from 1997 to 2002. Ferric gluconate and iron sucrose have become the predominant form of therapy. IV iron therapy was used in a much smaller percentage of PD compared with HD patients, and racial and geographic variability was observed.

Adolescent↗

Reuse-associated mortality in incident hemodialysis patients in the United States, 2000 to 2001.

BACKGROUND: The impact of dialyzer reuse on the mortality of hemodialysis patients is debated. This study assesses reuse-associated mortality across US dialysis provider systems (for-profit, not-for-profit; hospital-based, and freestanding units) in incident patients. METHODS: Incident Medicare hemodialysis patients who initiated dialysis therapy from January 1, 2000, to December 31, 2001, were included and followed up to December 31, 2002. A 3-month entry period was used to determine comorbidity and disease severity. Applying various analytic approaches, mortality rates for patients treated with reused (or reprocessed) or single-use dialyzers were compared. Because of differences among dialysis units, facility clustering was addressed. RESULTS: Of 75,831 patients, 61,391 patients (81.0%) were classified as on reuse, and 14,440 patients (19.0%), as on single use, as of the start of follow-up. The overall mortality rate was 25.0/100 patient-years. No difference in mortality risk was found between patients treated with reuse compared with single use in an intent-to-treat approach (hazard ratio, 0.98; 95% confidence interval, 0.94 to 1.02; P = 0.266) after adjusting for chain affiliation, for-profit status, year of dialysis inception, age, sex, race, renal diagnosis, comorbidity, and hospitalization days. Findings were similar in an as-treated approach (hazard ratio, 0.97; 95% confidence interval, 0.93 to 1.01; P = 0.136). No survival advantage associated with single use was found for subgroups. CONCLUSION: No overall survival advantage or disadvantage is associated with dialyzer reuse compared with single use in incident hemodialysis patients in the United States; however, continued monitoring is advised.

Adult↗

Effect of comorbidity on the increased mortality associated with early initiation of dialysis.

BACKGROUND: Current recommendations for initiating dialysis therapy are based on level of kidney function and clinical evidence of uremia. Several studies reported no benefit in patient survival from initiating dialysis therapy with a greater glomerular filtration rate (GFR). Whether this is explained by a greater comorbidity burden or detrimental effect of early initiation remains unclear. We thus undertook an evaluation of the impact of comorbidity on the association between GFR at initiation and death. METHODS: Data from the Center for Medicare & Medicaid Services were used to derive 3 incident dialysis populations: (1) general population aged 18+ years, (2) older patients aged 67+ years, and (3) a "low-risk" subgroup without diabetes, heart failure, or atherosclerotic heart disease. A Cox proportional hazard regression technique was used. RESULTS: Greater GFR at initiation of dialysis therapy was associated with a greater risk for death in all populations, and sequential adjustment for additional covariates attenuated the effect. Patients in the general dialysis population who initiated dialysis therapy at a GFR greater than 10 mL/min/1.73 m2 (>0.17 mL/s) had a 42% increased risk for death compared with patients with a GFR less than 5 mL/min/1.73 m2 (<0.08 mL/s) at initiation of dialysis therapy after adjusting for all covariates. In the older and healthier populations, adjusted increased risks were 25% and 39%, respectively. CONCLUSION: Patients initiating dialysis therapy at greater GFRs have an increased risk for death not fully explained by comorbidity. Additional research is required to determine the reasons for poor survival in patients who start dialysis therapy with significant residual renal function.

Adult↗

End stage renal disease in patients with Wilms tumor: results from the National Wilms Tumor Study Group and the United States Renal Data System.

PURPOSE: We sought to assess accurately the full spectrum of end stage renal disease (ESRD) in Wilms tumor survivors by combining the unique resources of the National Wilms Tumor Study Group (NWTSG) and the United States Renal Data System (USRDS), and to confirm preliminary reports of an increased incidence of ESRD in patients with the Wilms tumor-aniridia syndrome (WAGR). MATERIALS AND METHODS: ESRD was ascertained in 5,910 patients enrolled in NWTSG studies during 1969 to 1994 by record linkage to USRDS and by direct followup. Cumulative ESRD incidence was estimated accounting for intercurrent mortality. RESULTS: Of 115 cases of ESRD 10 (9%) were ascertained by the NWTSG alone, 13 (11%) by USRDS alone and 92 (80%) by both. Cumulative incidence of ESRD at 20 years from diagnosis of unilateral Wilms tumor was 74% for 17 patients with the Denys-Drash syndrome, 36% for 37 patients with WAGR, 7% for 125 male patients with hypospadias or cryptorchidism (genitourinary [GU] anomalies) and 0.6% for 5,347 patients with none of these conditions. The incidence of ESRD after diagnosis of bilateral Wilms tumor was 50% for the Denys-Drash syndrome (6 patients), 90% for WAGR (10), 25% for GU anomaly (25) and 12% for other (409). ESRD in patients with WAGR or GU anomalies tended to occur relatively late, often during or after adolescence. CONCLUSIONS: The risk of ESRD is remarkably low for the majority of patients with Wilms tumor. However, those with WAGR or associated GU anomalies are at higher risk and should be screened indefinitely to facilitate prospective treatment of impaired renal function.

Cause of Death↗