Background There is limited information about the clinical and prognostic significance of patient-reported recovery time. Study Design Prospective cohort study. Setting & Participants 6,040 patients in the DOPPS. Predictor Answer to question, “How long does it take you to recover from a dialysis session?” categorized as follows: <2, 2–6, 7–12, or >12 hours. Outcomes & Measurements Cross-sectional and longitudinal associations between recovery time and patient characteristics, hemodialysis treatment variables, health-related quality of life (HRQoL) and hospitalization and mortality. Results 32% reported recovery time <2 hours; 41%, 2–6 hours; 17%, 7–12 hours; and 10%, >12 hours. Using proportional odds (ordinal) logistic regression, shorter recovery time was associated with male sex, full-time employment, and higher serum albumin. Longer recovery time was associated with older age, dialysis vintage, body mass index, diabetes, and psychiatric disorder. Greater intradialytic weight loss, longer dialysis session length, and lower dialysate sodium concentration were associated with longer recovery time. In facilities that used uniform dialysate sodium concentration for ≥90% of patients, the adjusted OR of longer recovery time, comparing dialysate sodium concentration <140 vs 140 mEq/L, was 1.72 (95% CI, 1.37–2.16). Recovery time was positively correlated with symptoms of kidney failure and kidney disease burden score, and inversely correlated with HRQoL mental and physical component summary scores. Using Cox regression, adjusting for potential confounders not influenced by recovery time, it was positively associated with first hospitalization and mortality (adjusted HRs for recovery time >12 vs. 2–6 hours of 1.22 [95% CI, 1.09–1.37] and 1.47 [95% CI, 1.19–1.83], respectively). Limitations Answers are subjective and not supported by physiological measurements. Conclusions Recovery time can be used to identify patients with poorer HRQoL and higher risks of hospitalization and mortality. Interventions to reduce recovery time and possibly to improve clinical outcomes, such as increasing dialysate sodium concentration, need to be tested in randomized trials.

Background and objectives Elevated parathyroid hormone levels may be associated with adverse clinical outcomes in patients on dialysis. After the introduction of practice guidelines suggesting higher parathyroid hormone targets than those previously recommended, changes in parathyroid hormone levels and treatment regimens over time have not been well documented.Design, setting, participants, & measurements Using data from the international Dialysis Outcomes and Practice Patterns Study, trends in parathyroid hormone levels and secondary hyperparathyroidism therapies over the past 15 years and the associations between parathyroid hormone and clinical outcomes are reported; 35,655 participants from the Dialysis Outcomes and Practice Patterns Study phases 1-4 (1996-2011) were included.Results Median parathyroid hormone increased from phase 1 to phase 4 in all regions except for Japan, where it remained stable. Prescriptions of intravenous vitamin D analogs and cinacalcet increased and parathyroidectomy rates decreased in all regions over time. Compared with 150-300 pg/ml, in adjusted models, all-cause mortality risk was higher for parathyroid hormone=301-450 (hazard ratio, 1.09; 95% confidence interval, 1.01 to 1.18) and .600 pg/ml (hazard ratio, 1.23; 95% confidence interval, 1.12 to 1.34). Parathyroid hormone .600 pg/ml was also associated with higher risk of cardiovascular mortality as well as all-cause and cardiovascular hospitalizations. In a subgroup analysis of 5387 patients not receiving vitamin D analogs or cinacalcet and with no prior parathyroidectomy, very low parathyroid hormone (,50 pg/ml) was associated with mortality (hazard ratio, 1.25; 95% confidence interval, 1.04 to 1.51). ConclusionsIn a large international sample of patients on hemodialysis, parathyroid hormone levels increased in most countries, and secondary hyperparathyroidism treatments changed over time. Very low and very high parathyroid hormone levels were associated with adverse outcomes. In the absence of definitive evidence in support of a specific parathyroid hormone target, there is an urgent need for additional research to inform clinical practice.

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. 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 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 US. Prescription of high dialysate bicarbonate (≥38 mEq/L) was most common in the US (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 positively associated 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 with mortality was stronger in patients with longer dialysis vintage. Limitations Due to the observational nature of the current study, we cannot rule out that the reported associations may be biased by unmeasured confounders. Conclusions High dialysate bicarbonate, especially prolonged exposure, may contribute to adverse outcomes, likely through development of post-dialysis metabolic alkalosis. Additional studies are warranted to identify the optimal dialysate bicarbonate concentration.

SummaryBackground and objectives Demand for hemodialysis among elderly patients is increasing worldwide. Although clinical care of this high-risk group is complex and challenging, no guidelines exist to inform hemodialysis practices. The Dialysis Outcomes and Practice Patterns Study (DOPPS) provides a unique opportunity to assess dialysis practices and associated outcomes among elderly versus younger patients on chronic in-center hemodialysis in 12 countries. Results Although participant mean age increased over time in all DOPPS countries, the percentage of elderly varied widely. Overall, comorbidities and malnutrition were more common in the elderly. Fistulae were used less frequently among elderly versus younger patients in Europe and North America but not in Australia, New Zealand, and Japan. No difference in treatment time was observed between elderly and younger patients after normalizing for body weight. In all regions, ultrafiltration rates were lower among elderly patients. Elderly patients reported poorer quality of life with respect to the physical but not mental component scores. Mortality risk was three-to sixfold higher in the elderly group, whereas causes of death overall were similar for elderly and younger patients. Design, setting, participants, & measurements ConclusionsElderly patients represent a different proportion of DOPPS participants across countries, possibly reflecting differences in policies and clinical practices. In general, hemodialysis practices in the elderly reflected each region's clinical patterns, with some variation by age group depending upon the practice.

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Background Sudden death is a leading cause of death in patients on maintenance hemodialysis (HD). During HD sessions, the gradient between serum and dialysate levels results in rapid electrolytes shifts, which may contribute to arrhythmias and sudden death. Controversies exist on the optimal electrolyte concentration in the dialysate; specifically, it is unclear whether patient outcomes differ among those treated with dialysate potassium (DK) concentration of 3 mEq/L compared to 2 mEq/L. Study Design Prospective cohort study Setting & Participants 55,183 patients from 20 countries in the Dialysis Outcomes and Practice Patterns Study phases 1–5 (1996–2015). Predictor DK at study entry. Outcomes Cox regression was used to estimate the association between DK and both all-cause mortality and an arrhythmia composite outcome (arrhythmia-related hospitalization or sudden death), adjusting for potential confounders. Results During a median follow-up of 16.5 months, 24% of patients died and 7% had an arrhythmia composite outcome. No meaningful difference in clinical outcomes were observed for patients treated with DK 3 vs. 2 mEq/L; the adjusted hazard ratio (95% CI) was 0.96 (0.91, 1.01) for mortality and 0.98 (0.88, 1.08) for the arrhythmia composite. Results were similar across pre-dialysis serum potassium (SK) levels. As in prior studies, higher SK was associated with adverse outcomes. However, DK only had minimal impact on SK measured pre-dialysis (+0.09 mEq/L SK per 1 mEq/L DK; 95% CI: 0.05, 0.14). Limitations Data were not available on delivered (vs. prescribed) DK and post-dialysis SK; possible unmeasured confounding. Conclusions In combination, these results suggest that approaches other than altering DK concentration (e.g., education on dietary K sources, prescription of K-binding medications) may merit further attention to reduce risks associated with high SK.

Favorable levels of a variety of clinical markers may contribute to the better survival of patients receiving longer TT. These findings support longer TT prescription in the setting of in-center, three times per week HD.

SummaryBackground and objectives Hyperuricemia is associated with hypertension, coronary artery disease, and chronic kidney disease. However, there are no specific data on the relationship of uric acid to cardiovascular disease in the chronic hemodialysis setting.Design, setting, participants, & measurements Data from 5827 patients on chronic hemodialysis from six countries affiliated with the Dialysis Outcomes and Practice Patterns Study (DOPPS) were analyzed. All laboratory data were based upon the initial cross-section of patients in DOPPS I and II. Cox regression was used to calculate the hazard ratio (HR) of all-cause and cardiovascular (CV) mortality with adjustments for case-mix including 14 classes of comorbidity.Results There were no clinically significant differences in baseline characteristics between those who had measured uric acid (n ϭ 4637) and those who did not (n ϭ 1190). Uric acid level was associated with lower all-cause mortality (HR: 0.95, 95% confidence interval [CI]: 0.90 to 1.00 per 1 mg/dl higher uric acid level) and CV mortality (HR: 0.92, 95% CI: 0.86 to 0.99). When analyzed as a dichotomous variable, the adjusted HR at uric acid Յ8.2 mg/dl compared with Ͼ8.2 mg/dl was 1.24 (95% CI: 1.03 to 1.49) for all-cause mortality and 1.54 (95% CI: 1.15 to 2.07) for CV mortality. ConclusionsHigher uric acid levels were associated with lower risk of all-cause and CV mortality in the hemodialysis population. These results are in contrast to the association of hyperuricemia with higher cardiovascular risk in the general population and should be the subject of further research.