Pruritus in haemodialysis patients: International results from the Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: Pruritus affects many haemodialysis (HD) patients. In this study, pruritus and its relationship to morbidity, mortality, quality of life (QoL), sleep quality and patient laboratory measures were analysed in >300 dialysis units in 12 countries. METHODS: Pruritus data were collected from 18 801 HD patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) (1996-2004). Analyses were adjusted for age, gender, black race, Kt/V, haemoglobin, serum albumin, albumin-corrected serum calcium, serum phosphorus, 13 comorbidities, depression, years on dialysis, country and facility clustering effects. RESULTS: Moderate to extreme pruritus was experienced by 42% of prevalent HD patients in DOPPS during 2002/2003. Many patient characteristics were significantly associated with pruritus, but this did not explain the large differences in pruritus between countries (ranging from 36% in France to 50% in the UK) and between facilities (5-75%). Pruritus was slightly less common in patients starting HD than in patients on dialysis >3 months. Pruritus in new end-stage renal disease (ESRD) patients likely results from pre-existing conditions and not haemodialysis per se, indicating the need to understand development of pruritus before ESRD. Patients with moderate to extreme pruritus were more likely to feel drained [adjusted odds ratio (AOR) = 2.3-5.2, P < 0.0001] and to have poor sleep quality (AOR = 1.9-4.1, P < or = 0.0002), physician-diagnosed depression (AOR = 1.3-1.7, P < or = 0.004), and QoL mental and physical composite scores 3.1-8.6 points lower (P < 0.0001) than patients with no/mild pruritus. Pruritus in HD patients was associated with a 17% higher mortality risk (P < 0.0001), which was no longer significant after adjusting for sleep quality measures. CONCLUSIONS: The pruritus/mortality relationship may be substantially attributed to poor sleep quality. The many poor outcomes associated with pruritus underscore the need for better therapeutic agents to provide relief for the 40-50% of HD patients affected by pruritus.     

Body mass index and mortality in 'healthier' as compared with 'sicker' haemodialysis patients: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: Haemodialysis (HD) patients with lower body mass index (BMI) have a higher relative mortality risk (RR), irrespective of race. However, only Asian Americans treated with HD have been found to have an elevated RR with higher BMI. Asian Americans on HD are 'healthier' than other race groups (i.e. have better overall survival). We hypothesized that an increased mortality risk might be associated with high BMI in a variety of other 'healthier' subgroups of HD patients. METHODS: The prospective Dialysis Outcomes and Practice Patterns Study (DOPPS) provided baseline demographic, comorbidity and BMI data on 9714 HD patients in the US and Europe (France, Germany, Italy, Spain, and the UK) from 1996-2000. Using multivariate survival analyses, we evaluated BMI-mortality relationships in HD subpopulations defined by continent, race (black and white), gender, tertiles of severity of illness (based on a score derived from comorbid conditions and serum albumin concentration), age (<45, 45-64, >or=65), smoking, and diabetic status. RESULTS: Relative mortality risk decreased with increasing BMI. This was statistically significant (P<0.007) except for the smallest subgroup of patients who were <45 years old and were also in the healthiest tertile of comorbidity. All else equal, BMI <20 was consistently associated with the highest relative mortality risk. Overall a lower relative mortality risk (RR) as compared with BMI 23-24.9, was found for overweight (BMI 25-29.9; RR 0.84, P=0.008), for mild obesity (BMI 30-34.9; RR 0.73, P=0.0003), and for moderate obesity (BMI 35-39.9; RR 0.76, P=0.02). CONCLUSION: In a wide variety of HD patient subgroups, differing with respect to their baseline health status, increasing body size correlates with a decreased mortality risk. This contrasts with the association between BMI and mortality in the general population, and deserves further study.     

Mortality and hospitalization in haemodialysis patients in five European countries: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: Mortality and hospitalization rates are reported for nationally representative random samples of haemodialysis patients treated at randomly selected dialysis facilities in five European countries participating in the Dialysis Outcomes and Practice Pattern Study (DOPPS) (France, Germany, Italy, Spain and the UK). RESULTS: In the UK, 28.1% of haemodialysis patients received prior peritoneal dialysis treatment compared with 4.2-8.3% in other countries. Kidney transplantation rates ranged from 3.3 (per 100 patient years) in Italy to 11.6 in Spain. The relative risk (RR) of mortality, adjusted for age, sex and diabetes status was significantly higher in the UK (RR = 1.39, P = 0.02) compared with Italy (reference) and increased in association with age (RR = 1.60 for every 10 years older, P <0.001), diabetes as cause of end-stage renal disease (ESRD) (RR = 1.55, P < 0.001), male patients <65 years (RR = 1.29, P = 0.02) and peritoneal dialysis in the 12 months prior to starting haemodialysis (RR = 1.72, P = 0.06). Hospitalization for cardiovascular disease was highest in France and Germany (0.40 and 0.43 hospitalizations per patient year, respectively) and lowest in the UK (0.19), although cardiovascular comorbidity was similar in the UK and France. Hospitalization rates for vascular access-related infection ranged from 0.01 hospitalizations per patient year in Italy to 0.08 in the UK, consistent with the higher dialysis catheter use in the UK (25%) vs Italy (5%). Hospitalization risk was significantly higher in France than in other Euro-DOPPS countries and was significantly (P < 0.05) associated with prior peritoneal dialysis therapy, peripheral vascular disease, gastrointestinal bleeding in the prior 12 months, diabetes, cancer, cardiac disease, psychiatric disease and recent onset of ESRD (within 30 days of study entry). CONCLUSIONS: The large differences in haemodialysis practice and outcomes in the Euro-DOPPS countries suggest opportunities for improvement in patient care.     

Haemodialysis vascular access problems in Canada: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS II).

BACKGROUND: The optimal vascular access for chronic maintenance haemodialysis (HD) is the native arteriovenous fistula (AVF). Vascular access practice patterns are reported for a Canadian cohort of patients from the Dialysis Outcomes and Practice Patterns Study (DOPPS II). METHODS: DOPPS II is a prospective, observational study in 12 countries, including Canada. A representative random sample of 20 Canadian HD facilities and patients within those units were studied during 2002-2004. Canadian results were compared with those found in Europe and the USA. RESULTS: AVF use in Canadian prevalent (53%) and incident (26%) patients was lower than Canadian guidelines recommend (60%), and lower than in Europe [prevalent (74%), incident (50%)]. Despite 85% of Canadian HD patients having seen a nephrologist for > 1 month prior to starting dialysis, central venous catheter use in Canada (33% in prevalent patients, 70% in incident patients) was much higher than in Europe (prevalent 18%, incident 46%) and slightly higher than in the USA (prevalent 25%, incident 66%). This pattern is contrary to the preferences of Canadian medical directors and vascular access surgeons. The typical time from referral until permanent vascular access creation is substantially longer in Canada (61.7 days) than in Europe (29.4 days) or the USA (16 days). This longer delay time and higher catheter use in Canada may be a consequence of the significantly lower number of access surgeons per 100 HD patients in Canada (2.9) compared with the USA (8.1) and Europe (4.6). Furthermore, the median hours per week devoted to vascular access-related surgery per 100 patients is substantially lower in Canada (0.027 h) compared with the USA (0.082 h) and Europe (0.059 h). CONCLUSION: These findings suggest that Canadian chronic HD patients often rely on central venous catheters for vascular access, despite their known association with numerous detrimental outcomes in HD. Nephrologists, vascular access surgeons, interventional radiologists, other physicians and health care funding bodies must be more broadly educated about the priority of AVF creation as the preferred vascular access for chronic HD patients. They must work together to secure both the human and financial resources and other health care system enhancements to increase AVF creation rates in a timely manner.     

Anaemia in haemodialysis patients of five European countries: association with morbidity and mortality in the Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: The Dialysis Outcomes and Practice Patterns Study (DOPPS) is a prospective, observational study based on data collected from nationally representative samples of haemodialysis facilities. The burden of anaemia in haemodialysis patients is substantial, leading to considerable morbidity, mortality and reduced quality of life. This study examines anaemia management and outcomes based on data from five European countries participating in the DOPPS: France, Germany, Italy, Spain and the UK. METHODS: Baseline data on demographics, co-morbidities and anaemia management in 4591 haemodialysis patients from 101 nephrology facilities were collected in 1998-2000. Using multivariate Cox survival analyses to adjust for patient characteristics, relationships between haemoglobin concentration at study entry and rates of mortality and hospitalization were evaluated. RESULTS: For a year 2000 sample of prevalent patients on haemodialysis >180 days, mean haemoglobin concentration was 11.0 g/dl; 53% had a haemoglobin concentration > or = 11 g/dl [1998-1999 = 44% (P < 0.05)]. In 2000, 84% of prevalent patients were prescribed recombinant human erythropoietin (rHuEpo). Higher haemoglobin concentrations were associated with decreased relative risk (RR) for mortality (RR = 0.95 for every 1 g/dl higher haemoglobin, P = 0.03) and hospitalization (RR = 0.96, P = 0.02). Patients with haemoglobin <10 g/dl were 29% more likely to be hospitalized than patients with haemoglobin 11-12 g/dl (P < 0.001). CONCLUSION: Even after adjustment, lower haemoglobin concentrations were associated with higher morbidity and mortality in European haemodialysis patients. A trend to increased haemoglobin concentrations was observed following publication of the European Best Practice Guidelines (EBPG) on anaemia management for chronic kidney disease patients, but efforts must continue to achieve EBPG goals.     

Hypercalcaemia is associated with poor mental health in haemodialysis patients: results from Japan DOPPS.

BACKGROUND: The Dialysis Outcomes and Practice Patterns Study (DOPPS) reported high incidence of depression in haemodialysis patients. Hypercalcaemia and high parathyroid hormone (PTH) levels are aetiological factors of psychological disorders. We examined the association between mineral metabolism abnormalities and mental health in Japanese-DOPPS patients. METHODS: We used baseline data of Japan-DOPPS, Phase 1 (2755 patients, 1999-2001) and Phase 2 (2286 patients, 2002-03). The outcome variable was mental health using the mental health domain of SF-36. We examined the association between serum corrected calcium, phosphorus, calcium x phosphorus product and intact PTH concentrations, and mental health using analysis of covariance and also the associations between corrected calcium levels and current use of vitamin D and calcium-containing phosphate binder. RESULTS: There was a significant association between mental health and corrected calcium levels. A significantly lower mental health score was noted in patients with corrected calcium > or = 11 mg/dl than in <8.4 (P = 0.04), > or =8.4 to <10.2 (P = 0.009) and > or =10.2 to <11 mg/dl (P = 0.003). The association was significant even after adjustment for age, sex and other confounders. However, there was no relationship between intact PTH and mental health. High-corrected calcium levels were significantly associated with the use of intravenous active vitamin D and calcium-containing phosphate binder. CONCLUSIONS: Hypercalcaemia, but not high intact PTH, is associated with poor mental health in dialysis patients. While a cause-effect relationship between hypercalcaemia and deterioration of mental health needs further confirmation by longitudinal and prospective studies, our observational findings suggest the importance of control of serum calcium concentration in dialysis patients.     

Mineral metabolism and haemoglobin concentration among haemodialysis patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: Bone and mineral metabolism is abnormal in most chronic haemodialysis patients and is associated with a high mortality risk. Because of possible pathogenic links between anaemia and intact parathyroid hormone (iPTH), the present study evaluated associations of mineral metabolism indicators with haemoglobin (Hb). METHODS: Data were collected from 317 facilities (12 089 haemodialysis patients) in Australia, Belgium, Canada, France, Germany, Italy, Japan, New Zealand, Spain, Sweden, the United Kingdom and the United States by the Dialysis Outcomes and Practice Patterns Study (DOPPS). The major outcome studied was probability of haemodialysis patients having a target Hb, per guidelines, of >/=11 g/dl at baseline. Major predictor variables were patient characteristics and laboratory markers of mineral metabolism: albumin-corrected serum calcium (calcium(Alb)), serum phosphorus (PO(4)) and iPTH. Analyses were adjusted for demographics, 15 comorbidity classes, baseline laboratory values, body mass index, years on dialysis, erythropoietin dose, vitamin D and catheter use, cause of end-stage renal disease and country. RESULTS: The adjusted odds ratio (AOR) of having Hb >/=11 g/dl was significantly higher (P<0.0001) in patients with higher calcium(Alb) (AOR = 1.32 per 1 mg/dl), higher PO(4) (AOR = 1.08 per 1 mg/dl) and lower iPTH (AOR = 0.96 per 100 pg/ml). Furthermore, 4 month intrapatient changes in Hb concentration were significantly (P<0.0001) related to 4 month changes in calcium(Alb) (0.17 g/dl Hb rise per 1 mg/dl higher calcium(Alb)) and PO(4) (0.11 g/dl Hb rise per 1 mg/dl higher PO(4)). Mean weekly recombinant human erythropoietin (rHuEpo) doses were higher for patients with high PO(4) or iPTH levels, but lower for patients with calcium(Alb) >9.5 mg/dl, after patient mix and Hb concentration adjustments. CONCLUSIONS: The results of this study indicate that higher serum calcium(Alb) and PO(4) levels are each independently associated with better anaemia control. This relationship is independent of vitamin D use, PTH levels and prescribed rHuEpo dose. Despite this benefit of better anaemia control at higher serum calcium(Alb) and PO(4) concentrations, lower calcium and PO(4) levels, as recommended by the K/DOQI guidelines, should still serve as the long-term goal for HD patients in order to minimize tissue calcification and mortality risk.     

Starting and withdrawing haemodialysis--associations between nephrologists' opinions, patient characteristics and practice patterns (data from the Dialysis Outcomes and Practice Patterns Study).

BACKGROUND: The incidence and prevalence of haemodialysis vary widely across countries. The variation may be attributable to differences in the incidence of end-stage renal disease and/or in the availability of haemodialysis. Previous studies have identified differences in nephrologists' opinions about the availability of haemodialysis and its appropriateness for patients with comorbidities. We studied the associations between nephrologists' opinions, availability of haemodialysis, patient characteristics and comorbidities, and facilities' withdrawal rates. METHODS: Most of our analyses used data from 242 haemodialysis units in six countries (France, Germany, Italy, Spain, UK and the USA) in the first phase of the Dialysis Outcomes and Practice Patterns Study (DOPPS I). Opinions about access to and practice patterns in dialysis facilities, measured by the level of agreement with standardized statements, were collected from medical directors and nurse managers. A sub-analysis considered data from corresponding facilities in DOPPS II. RESULTS: We found wide variations in the prevalence of waiting lists for new dialysis patients (UK 60%; USA 25%; Germany 0%; P < 0.05), in agreement with starting haemodialysis for patients with advanced age, dementia and comorbidities (UK, France < USA < other countries; P < 0.05), and in agreement with withdrawing dialysis (other countries < UK/USA; P < 0.05). The estimated glomerular filtration rate at the start of dialysis was not significantly different in units with waiting lists. Significant associations were found between nephrologists' opinions and the odds of patients being > or =80 years old, and between opinions and the rate and relative risk of withdrawal of haemodialysis. No significant associations were found between opinions and patients' comorbidities or dependency. CONCLUSION: Differences within and across countries in nephrologists' opinions regarding starting and withdrawing haemodialysis reflect differences in access to haemodialysis and the practice of withdrawal of haemodialysis in their facilities.     

Health-related quality of life as a predictor of mortality and hospitalization: the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND: We investigated whether indicators of health-related quality of life (HRQOL) may predict the risk of death and hospitalization among hemodialysis patients treated in seven countries, taking into account serum albumin concentration and several other risk factors for death and hospitalization. We also compared HRQOL measures with serum albumin regarding their power to predict outcomes. METHODS: We analyzed data from the Dialysis Outcomes and Practice Patterns Study (DOPPS), an international, prospective, observational study of randomly selected hemodialysis patients in the United States (148 facilities), five European countries (101 facilities), and Japan (65 facilities). The total sample size was composed of 17,236 patients. Using the Kidney Disease Quality of Life Short Form (KDQOL-SFTM), we determined scores for three components of HRQOL: (1) physical component summary (PCS), (2) mental component summary (MCS), and (3) kidney disease component summary (KDCS). Complete responses on HRQOL measures were obtained from 10,030 patients. Cox models were used to assess associations between HRQOL and the risk of death and hospitalization, adjusted for multiple sociodemographic variables, comorbidities, and laboratory factors. RESULTS: For patients in the lowest quintile of PCS, the adjusted risk (RR) of death was 93% higher (RR = 1.93, P < 0.001) and the risk of hospitalization was 56% higher (RR = 1.56, P < 0.001) than it was for patients in the highest quintile level. The adjusted relative risk values of mortality per 10-point lower HRQOL score were 1.13 for MCS, 1.25 for PCS, and 1.11 for KDCS. The corresponding adjusted values for RR for first hospitalization were 1.06 for MCS, 1.15 for PCS, and 1.07 for KDCS. Each RR differed significantly from 1 (P < 0.001). For 1 g/dL lower serum albumin concentration, the RR of death adjusted for PCS, MCS, and KDCS and the other covariates was 1.17 (P < 0.01). Albumin was not significantly associated with hospitalization (RR = 1.03, P> 0.5). CONCLUSION: Lower scores for the three major components of HRQOL were strongly associated with higher risk of death and hospitalization in hemodialysis patients, independent of a series of demographic and comorbid factors. A 10-point lower PCS score was associated with higher elevation in the adjusted mortality risk, as was a 1 g/dL lower serum albumin level. More research is needed to assess whether interventions to improve quality of life lower these risks among hemodialysis patients.     

Anaemia in haemodialysis patients of five European countries: association with morbidity and mortality in the Dialysis Outcomes and Practice Patterns Study (DOPPS)

Nephrol Dial Transplant 2004; 19:     

Illness representations and quality of life scores in haemodialysis patients.

BACKGROUND: Health-related quality of life (QoL) in haemodialysis (HD) patients is a significant predictor of mortality and hospitalization. Patients' adaptation to a chronic disease is determined by their beliefs about illness and treatment. In this cross-sectional study we examined the impact of illness representations on QoL of HD patients and the influence of HD duration on this relationship. METHODS: Eighty-two clinically stable HD patients completed the Short Form-36 Health Survey (mean age 47.9+/-12.1, mean treatment duration 72+/-50.6, 53.6% males). Illness representations were assessed by a structured interview containing questions derived from The Revised Illness Perception Questionnaire. RESULTS: Our results indicate a relatively low QoL of HD patients, with an important proportion of patients scoring less than 43 for the physical component summary (65.9%) and less than 51 for the mental component summary (58.5%). HD patients consider their illness as having a chronic course, which they understand and control quite well. A higher personal control is associated with a lower emotional response and a better understanding of the disease. However, the perceived negative consequences of the disease upon patients' personal lives are considerable, as is their emotional response. Four of the six components of illness representations were strongly related to QoL parameters. On multiple regression analysis, between 15 and 31% in the variance of the physical and mental component of QoL was explained by three dimensions of illness representations: the perceived course of the disease, personal control and emotional response. Only the emotional response dimension of the illness representations is related to treatment duration (r = -0.48, P<0.01). CONCLUSION: Our study demonstrates important relationships between illness representations and QoL in end-stage renal disease patients treated by HD. Future research will have to plan for interventions that could alter illness representations in order to confirm the real impact of illness representations upon patients' QoL.