Hugh Rayner

Association of Comorbid Conditions and Mortality in Hemodialysis Patients in Europe, Japan, and the United States: The Dialysis Outcomes and Practice Patterns Study (DOPPS)

Mortality rates among hemodialysis patients vary greatly across regions. Representative databases containing extensive profiles of patient characteristics and outcomes are lacking. The Dialysis Outcomes and Practice Patterns Study (DOPPS) is a prospective, observational study of representative samples of hemodialysis patients in France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States (US) that captures extensive data relating to patient characteristics, prescriptions, laboratory values, practice patterns, and outcomes. This report describes the case-mix features and mortality among 16,720 patients followed up to 5 yr. The crude 1-yr mortality rates were 6.6% in Japan, 15.6% in Europe, and 21.7% in the US. After adjusting for age, gender, race, and 25 comorbid conditions, the relative risk (RR) of mortality was 2.84 (P < 0.0001) for Europe compared with Japan (reference group) and was 3.78 (P < 0.0001) for the US compared with Japan. The adjusted RR of mortality for the US versus Europe was 1.33 (P < 0.0001). For most comorbid diseases, prevalence was highest in the US, where the mean age (60.5 +/- 15.5 yr) was also highest. Older age and comorbidities were associated with increased risk of death (except for hypertension, which carried a multivariate RR of mortality of 0.74 [P < 0.0001]). Variability in demographic and comorbid conditions (as identified by dialysis facilities) explains only part of the differences in mortality between dialysis centers, both for comparisons made across continents and within the US. Adjustments for the observed variability will allow study of association between practice patterns and outcomes.

Facility Hemodialysis Vascular Access Use and Mortality in Countries Participating in DOPPS: An Instrumental Variable Analysis

BACKGROUND Previously, the Dialysis Outcomes and Practice Patterns Study (DOPPS) has shown large international variations in vascular access practice. Greater mortality risks have been seen for hemodialysis (HD) patients dialyzing with a catheter or graft versus a native arteriovenous fistula (AVF). To further understand the relationship between vascular access practice and outcomes, we have applied practice-based analyses (using an instrumental variable approach) to decrease the treatment-by-indication bias of prior patient-level analyses. STUDY DESIGN A prospective observational study of HD practices. SETTING & PARTICIPANTS Data collected from 1996 to 2004 from 28,196 HD patients from more than 300 dialysis units participating in the DOPPS in 12 countries. PREDICTOR OR FACTOR Patient-level or case-mix-adjusted facility-level vascular access use. OUTCOMES/MEASUREMENTS: Mortality and hospitalization risks. RESULTS After adjusting for demographics, comorbid conditions, and laboratory values, greater mortality risk was seen for patients using a catheter (relative risk, 1.32; 95% confidence interval, 1.22 to 1.42; P < 0.001) or graft (relative risk, 1.15; 95% confidence interval, 1.06 to 1.25; P < 0.001) versus an AVF. Every 20% greater case-mix-adjusted catheter use within a facility was associated with 20% greater mortality risk (versus facility AVF use, P < 0.001); and every 20% greater facility graft use was associated with 9% greater mortality risk (P < 0.001). Greater facility catheter and graft use were both associated with greater all-cause and infection-related hospitalization. Catheter and graft use were greater in the United States than in Japan and many European countries. More than half the 36% to 43% greater case-mix-adjusted mortality risk for HD patients in the United States versus the 5 European countries from the DOPPS I and II was attributable to differences in vascular access practice, even after adjusting for other HD practices. Vascular access practice differences accounted for nearly 30% of the greater US mortality compared with Japan. LIMITATIONS Possible existence of unmeasured facility- and patient-level confounders that could impact the relationship of vascular access use with outcomes. CONCLUSIONS Facility-based analyses diminish treatment-by-indication bias and suggest that less catheter and graft use improves patient survival.

Predicting a patient's choice of dialysis modality:Experience in a United Kingdom renal department

Education and counseling are important aspects of the management of patients starting dialysis. Free choice of modality may enhance patient well-being and, in the absence of clear survival benefits for either hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD), should have the major role in modality selection. This prospective study examines factors influencing this choice. Three hundred thirty-three new patients started renal replacement therapy at Birmingham Heartlands Hospital (Birmingham, UK) between August 1, 1992, and July 31, 1998. Data were incomplete for 14 patients, 11 patients were not counseled, and 54 patients had contraindications to a particular modality. The remaining 254 patients were offered a free choice. One hundred thirty-nine patients (55%) chose HD and 115 patients (45%) chose CAPD. Independent predictors for choosing CAPD rather than HD were being married (P = 0.004), being counseled before the start of dialysis (P = 0.019), and increased distance from the base unit (P < 0.001). Independent predictors for choosing HD were increasing age (P = 0.030) and male sex (P = 0.041). Use of these data should enhance planning of dialysis services and bring nearer the goal that all new patients with ESRD are able to have the dialysis modality of their choice.

Worldwide, mortality risk is high soon after initiation of hemodialysis

Mortality rates for maintenance hemodialysis patients are much higher than the general population and are even greater soon after starting dialysis. Here we analyzed mortality patterns in 86,886 patients in 11 countries focusing on the early dialysis period using data from the Dialysis Outcomes and Practice Patterns Study; a prospective cohort study of in-center hemodialysis. The primary outcome was all-cause mortality, using time-dependent Cox regression, stratified by study phase adjusted for age, sex, race, and diabetes. The main predictor was time since dialysis start as divided into early (up to 120 days), intermediate (121–365 days), and late (over 365 days) periods. Mortality rates (deaths/100 patient-years) were 26.7 (95% confidence intervals 25.6, 27.9), 16.9 (16.2, 17.6), and 13.7 (13.5, 14.0) in the early, intermediate, and late periods, respectively. In each country, mortality was higher in the early compared to the intermediate period with an adjusted range from 3.10 (2.22, 4.32) in Japan to 1.15 (0.87, 1.53) in the United Kingdom. Adjusted mortality rates were similar for intermediate and late periods. The ratio of elevated mortality rates in the early to the intermediate period increased with age. Within each period, mortality was higher in the United States than in most other countries. Thus, internationally, the early hemodialysis period is a high-risk time for all countries studied, with substantial differences in mortality between countries. Efforts to improve outcomes should focus on the transition period and first few months of dialysis.

The Associations of Social Support and Other Psychosocial Factors with Mortality and Quality of Life in the Dialysis Outcomes and Practice Patterns Study

BACKGROUND AND OBJECTIVES This study aimed to investigate the influence of social support and other psychosocial factors on mortality, adherence to medical care recommendations, and physical quality of life among hemodialysis patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Data on 32,332 hemodialysis patients enrolled in the Dialysis Outcomes and Practice Patterns Study (1996 to 2008) in 12 countries were analyzed. Social support and other psychosocial factors related to ESRD and its treatment were measured by patient self-reports of health interference with social activities, isolation, feeling like a burden, and support from family and dialysis staff. Cox regression and logistic regression were used to examine associations of baseline social support and other psychosocial factors with all-cause mortality and with other measured outcomes at baseline, adjusting for potential confounders. RESULTS Mortality was higher among patients reporting that their health interfered with social activities, were isolated, felt like a burden, and were dissatisfied with family support. Poorer family support and several psychosocial measures also were associated with lower adherence to the prescribed hemodialysis length and the recommended weight gain between sessions. Some international differences were observed. Poorer self-reported social support and other psychosocial factors were associated with poor physical quality of life. CONCLUSIONS Poorer social support and other psychosocial factors are associated with higher mortality risk, lower adherence to medical care, and poorer physical quality of life in hemodialysis patients. More research is needed to assess whether interventions to improve social support and other psychosocial factors will lengthen survival and enhance quality of life.

Enhanced training in vascular access creation predicts arteriovenous fistula placement and patency in hemodialysis patients: results from the Dialysis Outcomes and Practice Patterns Study.

Objective:To investigate whether intensity of surgical training influences type of vascular access placed and fistula survival. Summary Background Data:Wide variations in fistula placement and survival occur internationally. Underlying explanations are not well understood. Methods:Prospective data from 12 countries in the Dialysis Outcomes and Practice Patterns Study were analyzed; outcomes of interest were type of vascular access in use (fistula vs. graft) in hemodialysis patients at study entry and time from placement until primary and secondary access failures, as predicted by surgical training. Logistic and Cox regression models were adjusted for patient characteristics and time on hemodialysis. Results:During training, US surgeons created fewer fistulae (US mean = 16 vs. 39–426 in other countries) and noted less emphasis on vascular access placement compared with surgeons elsewhere. Significant predictors of fistula versus graft placement in hemodialysis patients included number of fistulae placed during training (adjusted odds ratio [AOR] = 2.2 for fistula placement, per 2 times greater number of fistulae placed during training, P < 0.0001) and degree of emphasis on vascular access creation during training (AOR = 2.4 for fistula placement, for much-to-extreme emphasis vs. no emphasis, P = 0.0008). Risk of primary fistula failure was 34% lower (relative risk = 0.66, P = 0.002) when placed by surgeons who created ≥25 (vs. <25) fistulae during training. Conclusions:Surgical training is key to both fistula placement and survival, yet US surgical programs seem to place less emphasis on fistula creation than those in other countries. Enhancing surgical training in fistula creation would help meet targets of the Fistula First Initiative.

Dialysate Sodium Concentration and the Association with Interdialytic Weight Gain, Hospitalization, and Mortality

BACKGROUND AND OBJECTIVES Recommendations to decrease the dialysate sodium (DNa) prescription demand analyses of patient outcomes. We analyzed morbidity and mortality at various levels of DNa, simultaneously accounting for interdialytic weight gain (IDWG) and for the mortality risk associated with lower predialysis serum sodium (SNa) levels. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We used multiply-adjusted linear mixed models to evaluate the magnitude of IDWG and Cox proportional hazards models to assess hospitalizations and deaths in 29,593 patients from the Dialysis Outcomes and Practice Patterns Study with baseline DNa and SNa as predictors, categorized according to lowest to highest levels. RESULTS IDWG increased with higher DNa across all SNa categories, by 0.17% of body weight per 2 mEq/L higher DNa; however, higher DNa was not associated with higher mortality in a fully adjusted model (also adjusted for SNa; hazard ratio [HR]=0.98 per 2 mEq/L higher DNa, 95% confidence interval [CI] 0.95-1.02). Instead, higher DNa was associated with lower hospitalization risk (HR=0.97 per 2 mEq/L higher DNa, 95% CI 0.95-1.00, P=0.04). Additional adjustments for IDWG did not change these results. In sensitivity analyses restricted to study facilities, in which 90%-100% of patients have the same DNa (56%), the adjusted HR for mortality was 0.88 per 2 mEq/L higher DNa (95% CI 0.83-0.94). These analyses represented a pseudo-randomized experiment in which the association between DNa and mortality is unlikely to have been confounded by indication. CONCLUSIONS In the absence of randomized prospective studies, the benefit of reducing IDWG by decreasing DNa prescriptions should be carefully weighed against an increased risk for adverse outcomes.

Travel Time to Dialysis as a Predictor of Health-Related Quality of Life, Adherence, and Mortality: The Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND Longer travel time to the dialysis unit creates a substantial burden for many patients. This study evaluated the effect of self-reported 1-way travel time to hemodialysis on mortality, health-related quality of life (HR-QOL), adherence, withdrawal from dialysis therapy, hospitalization, and transplantation. STUDY DESIGN Prospective observational cohort. SETTING & PARTICIPANTS Patients enrolled in the Dialysis Outcomes and Practices Patterns Study who completed a patient questionnaire (n = 20,994). PREDICTOR One-way travel time to hemodialysis treatment, categorized as 15 or less, 16 to 30, 31 to 60, and longer than 60 minutes. Covariates included demographics, comorbid conditions, serum albumin level, time on dialysis therapy, and country. OUTCOME & MEASUREMENT HR-QOL was examined by using a linear mixed model. Cox proportional hazards regression was used to examine associations with mortality, withdrawal from dialysis therapy, hospitalization, and transplantation. RESULTS Longer travel time was associated with greater adjusted relative risk (RR) of death (P = 0.05 for overall trend). Adjusted HR-QOL subscales were significantly lower for those with longer travel times compared with those traveling 15 minutes or less. There were no associations of travel time with withdrawal from dialysis therapy (P = 0.6), hospitalization (P = 0.4), or transplantation (P = 0.7). LIMITATIONS The questionnaire nonresponse rate was substantial, and nonresponders were older, with more comorbid conditions. Travel time was assessed by using a single nonvalidated question. CONCLUSIONS Longer travel time is associated significantly with greater mortality risk and decreased HR-QOL. Exploring opportunities to decrease travel time should be incorporated into the dialysis clinical routine.

Association of Dialysate Bicarbonate Concentration With Mortality in the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND Most hemodialysis patients worldwide are treated with bicarbonate dialysis using sodium bicarbonate as the base. Few studies have assessed outcomes of patients treated with different dialysate bicarbonate levels, and the optimal concentration remains uncertain. STUDY DESIGN The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective cohort study. SETTING & PARTICIPANTS This study included 17,031 patients receiving thrice-weekly in-center hemodialysis from 11 DOPPS countries (2002-2011). PREDICTOR Dialysate bicarbonate concentration. OUTCOMES All-cause and cause-specific mortality and first hospitalization, using Cox regression to estimate the effects of dialysate bicarbonate concentration, adjusting for potential confounders. MEASUREMENTS Demographics, comorbid conditions, laboratory values, and prescriptions were abstracted from medical records. RESULTS Mean dialysate bicarbonate concentration was 35.5 ± 2.7 (SD) mEq/L, ranging from 32.2 ± 2.3 mEq/L in Germany to 37.0 ± 2.6 mEq/L in the United States. Prescription of high dialysate bicarbonate concentration (≥38 mEq/L) was most common in the United States (45% of patients). Approximately 50% of DOPPS facilities used a single dialysate bicarbonate concentration. 3,913 patients (23%) died during follow-up. Dialysate bicarbonate concentration was associated positively with mortality (adjusted HR, 1.08 per 4 mEq/L higher [95% CI, 1.01-1.15]; HR for dialysate bicarbonate ≥38 vs 33-37 mEq/L, 1.07 [95% CI, 0.97-1.19]). Results were consistent across levels of pre-dialysis session serum bicarbonate and between facilities that used a single dialysate bicarbonate concentration and those that prescribed different concentrations to individual patients. The association of dialysis bicarbonate concentration with mortality was stronger in patients with longer dialysis vintage. LIMITATIONS Due to the observational nature of the present study, we cannot rule out that the reported associations may be biased by unmeasured confounders. CONCLUSIONS High dialysate bicarbonate concentrations, especially prolonged exposure, may contribute to adverse outcomes, likely through the development of postdialysis metabolic alkalosis. Additional studies are warranted to identify the optimal dialysate bicarbonate concentration.

Understanding by older patients of dialysis and conservative management for chronic kidney failure

Background Older adults with chronic kidney disease stage 5 may be offered a choice between dialysis and conservative management. Few studies have explored patients’ reasons for choosing conservative management and none have compared the views of those who have chosen different treatments across renal units. Study Design Qualitative study with semistructured interviews. Settings & Participants Patients 75 years or older recruited from 9 renal units. Units were chosen to reflect variation in the scale of delivery of conservative management. Methodology Semistructured interviews audiorecorded and transcribed verbatim. Analytical Approach Data were analyzed using thematic analysis. Results 42 interviews were completed, 4 to 6 per renal unit. Patients were sampled from those receiving dialysis, those preparing for dialysis, and those choosing conservative management. 14 patients in each group were interviewed. Patients who had chosen different treatments held varying beliefs about what dialysis could offer. The information that patients reported receiving from clinical staff differed between units. Patients from units with a more established conservative management pathway were more aware of conservative management, less often believed that dialysis would guarantee longevity, and more often had discussed the future with staff. Some patients receiving conservative management reported that they would have dialysis if they became unwell in the future, indicating the conditional nature of their decision. Limitations Recruitment of older adults with frailty and comorbid conditions was difficult and therefore transferability of findings to this population is limited. Conclusions Older adults with chronic kidney disease stage 5 who have chosen different treatment options have contrasting beliefs about the likely outcomes of dialysis for those who are influenced by information provided by renal units. Supporting renal staff in discussing conservative management as a valid alternative to dialysis for a subset of patients will aid informed decision making. There is a need for better evidence about conservative management to support shared decision making for older people with chronic kidney failure.