United States Renal Data System assessment of the impact of the National Kidney Foundation-Dialysis Outcomes Quality Initiative guidelines.

Since 1989, significant efforts have focused on improving the care of dialysis patients in the United States. Numerous organizations have developed clinical practice guidelines; however, few guidelines have received the broad support given to the National Kidney Foundation-Dialysis Outcomes Quality Initiative (DOQI). These guidelines, independently developed from an extensive review of the literature, include sections on dialysis adequacy, anemia treatment, and vascular access. To assess the impact of these guidelines on clinical practice, we evaluated data on hematocrits, recombinant human erythropoietin dosing, hemodialysis adequacy, and simple fistula and dialysis catheter utilization using Medicare dialysis provider claims and Medicare Part B physician services. Hematocrits have increased steadily, with the exception of the period when the Hematocrit Measurement Audit was in effect. After cancellation of the policy, hematocrits increased to the midpoint of the DOQI target range (34.4%). Although the level of dialysis therapy has stabilized, with the average urea reduction rate of 68% to 69.9% in 1997 to 1999 being slightly greater than the DOQI target of 65% or greater, geographic variability is apparent. Simple fistula placement rates increased by 45% during the pre-DOQI and post-DOQI period from 1994 to 1999. The use of temporary catheters decreased, whereas placement of permanent catheters has increased, which may reflect recommended practice guidelines. Although it appears that clinical practice guidelines have improved the clinical care of dialysis patients, considerable regional variations in care across the country should be given significant attention.

Peritoneal and hemodialysis: I. Differences in patient characteristics at initiation.

BACKGROUND: Comparisons of mortality outcomes between peritoneal dialysis (PD) and hemodialysis (HD) patients have shown varying results, which may be caused by the unequally distributed clinical conditions of patients at initiation. To address this issue, we evaluated the clinical characteristics of 105,954 patients at the initiation of PD and HD, using the U.S. national incidence data on treated end-stage renal disease from the Medical Evidence Form, 1995 to 1997. METHODS: A general linear model was used to analyze differences of age, albumin, creatinine, blood urea nitrogen (BUN), and hematocrit; categorical data analysis to evaluate body mass index (BMI), grouped into four categories: < 19, 19-25 (< 25), 25-30 (< 30), and 30+; and logistic regression to assess the likelihood of initiating PD versus HD. Diabetics (DM) were analyzed separately from non-diabetics (NDM). Explanatory variables in the logistic regression included incidence year, race, gender, age, BMI, albumin, creatinine, BUN, and hematocrit. Race included white and black. Age was categorized into four groups: 20-44, 45-64, 65-74, and 75+. RESULTS: At the initiation of dialysis PD patients were approximately 6 years younger (P < 0.0001) than HD patients. PD patients also had higher (P < 0.0001) albumin (+0.35 g/dL for DM and +0.23 g/dL for NDM) and hematocrit (+1.64% for DM and +1.71% for NDM) levels, and lower (P < 0.04) BUN (-8.75 mg/dL for DM and -5.24 mg/dL for NDM) and creatinine (-0.51 mg/dL for DM and -0.23 mg/dL for NDM) levels than HD patients. Whites had a higher (P < 0.0001) likelihood of starting PD than blacks, and patients with BMI <19 had a lower (P < 0.0001) chance of beginning on PD. CONCLUSION: PD patients had favorable clinical conditions at the initiation of dialysis, which should be taken into consideration when comparing dialysis outcomes between the two modalities.

Peritoneal and hemodialysis: II. Mortality risk associated with initial patient characteristics.

BACKGROUND: Patients initiating with peritoneal dialysis (PD) have favorable clinical conditions compared with hemodialysis (HD) patients, which may contribute to the varying results found in studies of mortality across the two therapies. METHODS: National incidence data of end-stage renal disease patients from 1995 to 1997 were used, excluding the first 90 days of treatment and including all patients who were on either PD or HD on day 91. Patients were then followed for a one-year period. A Cox proportional hazards regression analysis was used, separating diabetics and non-diabetics, and two statistical models were applied. Model 1 included race, gender, age, initial modality, and incidence year as explanatory variables. Model 2 added body mass index (BMI), initial levels of serum albumin, creatinine, and blood urea nitrogen. RESULTS: Age was most highly associated with mortality, followed by biochemical variables, BMI, gender, and dialysis modality. In diabetics, the hazard ratio (HR) from Model 1 indicated no difference [1.046, 95% confidence limits (CL) 0.989-1.105; P> 0.1, HD was the reference] in mortality between PD and HD, while Model 2 demonstrated that PD patients had a 13.4% (1.134, CL 1.072-1.100, P < 0.0001) higher chance of death. In non-diabetics, hazard ratios (HRs) from Models 1 and 2 indicated that PD patients had a 23.5% (0.765, 0.722-0.812, P < 0.0001) and 11.9% (0.881, 0.30-0.935, P < 0.0001), respectively, lower likelihood of death than HD patients. CONCLUSION: Our study indicates that the results changed depending on the analytical methods used. We recommend that, due to the unequally distributed clinical conditions of patients at initiation, comparisons of mortality outcomes between dialysis modalities should be made with caution.