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Hemodialysis (HEMO) Study Group

Publications and source records attributed to Hemodialysis (HEMO) Study Group.

8 recordsLinked to original sources

Cerebrovascular disease in maintenance hemodialysis patients: results of the HEMO Study.

BACKGROUND: Cerebrovascular disease (CBVD) in hemodialysis patients is associated with significant morbidity and mortality. A secondary analysis of CBVD in the Hemodialysis (HEMO) Study was performed. Specific objectives were to: (1) determine risk factors for the presence of CBVD at baseline, (2) assess risk factors for the subsequent occurrence of cerebrovascular deaths, and (3) analyze the effects of dose and flux on cerebrovascular mortality. METHODS: The HEMO Study was a randomized multicenter study evaluating the effects of high-dose versus standard-dose and high-flux versus low-flux hemodialysis. There were 1,846 patients enrolled, with a mean follow-up of 2.84 years. RESULTS: Factors associated with the baseline presence of CBVD included age (P < 0.0001), presence of any cardiac disease (P < 0.0001), and diabetes mellitus (P < 0.0001). There were 65 deaths caused by CBVD (event rate, 1.2/100 patient-years). Multivariate Cox regression using a backward-variables selection procedure showed that diabetes, lower albumin level, greater hematocrit, and lower body mass index at baseline were associated significantly with subsequent CBVD death. There was no effect of flux or dose on overall rate of CBVD deaths. However, an interaction was found between baseline CBVD status and flux intervention on CBVD death (P = 0.016). In the subgroup of patients without the baseline presence of CBVD, high-flux dialysis was associated with a lower risk for death caused by CBVD (P = 0.016). A borderline interaction between years of dialysis therapy and flux on subsequent CBVD death was detected (P = 0.05). The beneficial effect of high flux was evident in those on hemodialysis therapy for longer than 3.7 years (P = 0.012). CONCLUSION: High flux was associated with decreased CBVD mortality in those without known CBVD at baseline and those on hemodialysis therapy for longer than 3.7 years. This secondary analysis strengthens, but does not prove, the hypothesis that high-flux treatment may attenuate the death rate from vascular disease.

Aged↗

Self-reported appetite, hospitalization and death in haemodialysis patients: findings from the Hemodialysis (HEMO) Study.

BACKGROUND: Anorexia is an important cause of protein-energy malnutrition (PEM) in haemodialysis patients. We investigated whether self-reported appetite was associated with death and hospitalization in subjects enrolled in the Hemodialysis (HEMO) Study. METHODS: The HEMO Study was a 7-year, multicentre, randomized trial (N = 1846), which examined the effects of dialysis dose and membrane flux on mortality and morbidity. Three questions from the Appetite and Diet Assessment Tool (ADAT) were used to determine whether appetite had changed over time in the randomized treatment groups. The relations among ADAT scores, dietary protein and energy intakes, biochemical and anthropometric measures, and quality of life were assessed. We used Cox proportional hazards models to evaluate the relative risks of death and hospitalization associated with static and dynamic ADAT scores, adjusted for demographic factors, dose and flux assignments, and co-morbidity. RESULTS: The average length of follow-up was 2.84 years. After adjusting for demographic factors and randomized treatment assignments, there was a significant association between poorer self-reported appetite and death (RR 1.52, 95% CI 1.16-1.98); however, the association became non-significant with further adjustment for co-morbidity (RR 1.23, 95% CI 0.94-1.62). Poorer appetite was unequivocally associated with increased hospitalization rates (multivariable RR 1.35, 95% CI 1.13-1.61). The longitudinal effect of worsening appetite from baseline to 1 year was not associated with mortality or hospitalization rate after adjusting for co-morbidity. CONCLUSIONS: The association between appetite and death was confounded by co-morbidity. Self-reported appetite was associated with hospitalization rate in haemodialysis patients and, thus, it may be a useful screening tool for this outcome. Patients who report poor or very poor appetites should be monitored, and they should receive more comprehensive nutritional assessments.

Adolescent↗

Effects of dietary intake, appetite, and eating habits on dialysis and non-dialysis treatment days in hemodialysis patients: cross-sectional results from the HEMO study.

OBJECTIVE: To evaluate differences between dietary energy intake (DEI), dietary protein intake (DPI), appetite, dietary patterns, and eating habits during dialysis treatment days (DD) and non-dialysis treatment days (NDD) in 1,901 adults receiving maintenance hemodialysis who were enrolled in the baseline phase of the National Institutes of Health-sponsored Hemodialysis (HEMO) study. DESIGN: A cross-sectional analysis of participants at baseline (before randomization). SETTING: Fifteen clinical centers across the United States. MEASUREMENTS: DEI, DPI, and self-reported assessment of appetite, dietary patterns, and eating habits. RESULTS: For the entire study cohort, total mean (+/- SD) DEI (1,566 +/- 636 kcal/day) and weight-adjusted DEI (23.2 +/- 9.5 kcal/kg/day) were significantly higher (P <.0001) on NDD than on DD (1,488 +/- 620 kcal/day and 22.2 +/- 9.6 kcal/kg/day), respectively. Similarly, DPI was significantly higher (P <.0001) on NDD (65.0 +/- 29.0 g/day and 0.96 +/- 0.43 g/kg/day) than on DD (60.2 +/- 26.5 g/day and 0.90 +/- 0.41 g/kg/day). On DD and NDD, the mean weight-adjusted DEI for the entire cohort was less than the HEMO study standard of care (SOC) of > or =28 kcal/kg/day, whereas on NDD, several subgroups reported dietary protein intakes that were closer to the study's SOC. These included men, patients under 50 years of age, nonblack participants, those without diabetes, those with a normal or mild Index of Co-Existing Disease score, and those on dialysis for more than 5 years. Protein and energy intakes declined with worsening self-reported appetites in both DD and NDD after adjusting for other subgroup effects. CONCLUSION: Dietary energy and protein intakes of HEMO study participants were lower on DD than on NDD, and also lower than the SOC on both days, particularly with regard to energy intake. People receiving maintenance hemodialysis should be counseled to consume adequate amounts of energy and protein daily, especially on DD. Practitioners should monitor closely those patients who report poor appetite and should intervene appropriately.

Adult↗

Anthropometrically estimated total body water volumes are larger than modeled urea volume in chronic hemodialysis patients: effects of age, race, and gender.

BACKGROUND: The modeled volume of urea distribution (Vm) in intermittently hemodialyzed patients is often compared with total body water (TBW) volume predicted from population studies of patient anthropometrics (Vant). METHODS: Using data from the HEMO Study, we compared Vm determined by both blood-side and dialysate-side urea kinetic models with Vant as calculated by the Watson, Hume-Weyers, and Chertow anthropometric equations. RESULTS: Median levels of dialysate-based Vm and blood-based Vm agreed (43% and 44% of body weight, respectively). These volumes were lower than anthropometric estimates of TBW, which had median values of 52% to 55% of body weight for the three formulas evaluated. The difference between the Watson equation for TBW and modeled urea volume was greater in Caucasians (19%) than in African Americans (13%). Correlations between Vm and Vant determined by each of the three anthropometric estimation equations were similar; but Vant derived from the Watson formula had a slightly higher correlation with Vm. The difference between Vm and the anthropometric formulas was greatest with the Chertow equation, less with the Hume-Weyers formula, and least with the Watson estimate. The age term in the Watson equation for men that adjusts Vant downward with increasing age reduced an age effect on the difference between Vant and Vm in men. CONCLUSION: The findings show that kinetically derived values for V from blood-side and dialysate-side modeling are similar, and that these modeled urea volumes are lower by a substantial amount than anthropometric estimates of TBW. The higher values for anthropometry-derived TBW in hemodialyzed patients could be due to measurement errors. However, the possibility exists that TBW space is contracted in patients with end-stage renal disease (ESRD) or that the TBW space and the urea distribution space are not identical.

Black or African American↗

Effect of dialysis dose and membrane flux in maintenance hemodialysis.

BACKGROUND: The effects of the dose of dialysis and the level of flux of the dialyzer membrane on mortality and morbidity among patients undergoing maintenance hemodialysis are uncertain. METHODS: We undertook a randomized clinical trial in 1846 patients undergoing thrice-weekly dialysis, using a two-by-two factorial design to assign patients randomly to a standard or high dose of dialysis and to a low-flux or high-flux dialyzer. RESULTS: In the standard-dose group, the mean (+/-SD) urea-reduction ratio was 66.3+/-2.5 percent, the single-pool Kt/V was 1.32+/-0.09, and the equilibrated Kt/V was 1.16+/-0.08; in the high-dose group, the values were 75.2+/-2.5 percent, 1.71+/-0.11, and 1.53+/-0.09, respectively. Flux, estimated on the basis of beta2-microglobulin clearance, was 3+/-7 ml per minute in the low-flux group and 34+/-11 ml per minute in the high-flux group. The primary outcome, death from any cause, was not significantly influenced by the dose or flux assignment: the relative risk of death in the high-dose group as compared with the standard-dose group was 0.96 (95 percent confidence interval, 0.84 to 1.10; P=0.53), and the relative risk of death in the high-flux group as compared with the low-flux group was 0.92 (95 percent confidence interval, 0.81 to 1.05; P=0.23). The main secondary outcomes (first hospitalization for cardiac causes or death from any cause, first hospitalization for infection or death from any cause, first 15 percent decrease in the serum albumin level or death from any cause, and all hospitalizations not related to vascular access) also did not differ significantly between either the dose groups or the flux groups. Possible benefits of the dose or flux interventions were suggested in two of seven prespecified subgroups of patients. CONCLUSIONS: Patients undergoing hemodialysis thrice weekly appear to have no major benefit from a higher dialysis dose than that recommended by current U.S. guidelines or from the use of a high-flux membrane.

Adult↗

Association of nutritional markers with physical and mental health status in prevalent hemodialysis patients from the HEMO study.

OBJECTIVE: To determine associations of potentially modifiable nutritional factors with physical and mental health status after adjusting for sociodemographic and comorbid conditions. DESIGN: Cross-sectional multivariable analysis. SETTING: Fifteen dialysis centers across the United States participating in the Reduction of Morbidity and Mortality Among Hemodialysis Patients (HEMO) study. PATIENTS: Enrollment of 1,545 prevalent hemodialysis subjects in the HEMO study. INDEPENDENT (PREDICTOR) VARIABLES: The following nutritional markers were assessed in this analysis: serum albumin, energy intake, protein catabolic rate, serum creatinine, midarm muscle circumference, calf circumference, and smoking status. Smoking status, although not a nutritional factor per se, was also included because it is a modifiable lifestyle factor. MAIN OUTCOME MEASURES: Physical and mental health status were assessed using the medical staff-assessed Karnofsky Index and the patient self-assessed Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). RESULTS: After adjusting for sociodemographic factors and comorbid conditions, serum albumin, serum creatinine, and calf circumference were independently associated with Karnofsky Index scores. Similarly, serum creatinine and calf circumference were also independently associated with the Physical Component Summary (PCS) score of the SF-36. Of the nutritional variables selected, no variables were significantly associated with the Mental Component Summary (MCS) score of the SF-36. CONCLUSIONS: Markers of poor nutrition were associated with decreased physical functioning scores, independent of case mix. Measures that improve nutrition may therefore have wide-reaching effects to improve not only morbidity and mortality but also health-related quality of life for patients with end-stage renal disease.

Adolescent↗

Comorbidity assessment using the Index of Coexistent Diseases in a multicenter clinical trial.

BACKGROUND: The Hemodialysis (HEMO) Study is a multicenter trial designed to determine whether hemodialysis dose and membrane flux affect survival. Comorbid conditions are also important determinants of survival, and thus, an accurate and reliable method to assess comorbidity was required. Comorbidity was being assessed at baseline and annually in the HEMO Study using the Index of Coexistent Disease (ICED). We describe the instrument, its implementation in the HEMO Study, and the results of comorbidity assessment in the first 1000 randomized patients in the trial. METHODS: The ICED aggregated the presence and severity of 19 medical conditions and 11 physical impairments within two scales: the Index of Disease Severity (IDS) and the Index of Physical Impairment (IPI). The final ICED score was determined by an algorithm combining the peak scores for the IDS and IPI. The range of the ICED was from 0 to 3, reflecting increasing severity. RESULTS: Study personnel at 15 clinical centers were trained to update and abstract data from the dialysis medical records. Availability of data, measures of construct validity, and measures of reliability were adequate; 99.8% and 60.6% of patients had comorbid conditions in at least one IDS or IPI category, respectively. The distribution of patients by ICED level was 0 (0.2%), 1 (34.9%), 2 (31.2%), and 3 (33.7%). In multivariable analysis, the following factors were significantly associated with more severe comorbidity: older age, diabetes and other causes of renal disease, a lower level of education, employment status (unemployed and retired), longer duration of dialysis, and lower serum creatinine. There was a significant variation in the severity of comorbidity among clinical centers after adjustment for other factors. The R2 of the model was 25.3%, indicating that a substantial proportion of the variation in the ICED was not explained by these factors. CONCLUSIONS: We conclude that comorbidity assessment using the ICED is feasible in multicenter clinical trials of dialysis patients. There is a large burden of comorbidity in dialysis patients, which is not well explained by the cause of renal disease, demographic, and socioeconomic factors and common clinical and laboratory measurements. These variables should not be considered substitutes for comorbid conditions in case-mix adjustment. Comorbidity assessment is useful to describe the sample population, to improve the precision of the treatment effect, and to use possibly as an outcome measurement.

Comorbidity↗