Microbiology and outcomes of polymicrobial peritonitis associated with peritoneal dialysis: a register-based cohort study from the French Language Peritoneal Dialysis Registry.

BACKGROUND: Previous studies have reported that polymicrobial peritonitis in peritoneal dialysis (PD) is associated with poor outcomes, but recent data from European cohorts are scarce. METHODS: We included from the French Language Peritoneal Dialysis Registry all patients ≥18 years of age who started PD between January 2014 and November 2020. We compared microbiology and patient characteristics associated with mono- and polymicrobial peritonitis. We assessed patient outcomes after a first polymicrobial peritonitis using survival analysis with competing events. We differentiated microorganisms isolated from dialysis effluent as enteric or non-enteric pathogens. RESULTS: A total of 8848 patients contributed 13 023 patient-years of follow-up and 3348 culture-positive peritonitis episodes, including 251 polymicrobial ones. This corresponded to rates of 0.32 and 0.02 episodes/patient-year, respectively. For most patients (72%) who experienced polymicrobial peritonitis, this was their first peritonitis episode. Enteric pathogens were more frequently isolated in polymicrobial than in monomicrobial peritonitis (57 versus 44%; P < .001). In both cases of peritonitis with and without enteric pathogens, the polymicrobial versus monomicrobial character of the peritonitis was not associated with mortality in patients who did not switch to haemodialysis {adjusted cause-specific hazard ratio [acsHR] 1.2 [95% confidence interval (CI) 0.3-5.0], P = .78 and 1.1 [95% CI 0.7-1.8], P = .73, respectively}. However, the risks of death and switch to haemodialysis were higher for monomicrobial peritonitis with enteric pathogens compared with those without [acsHR 1.3 (95% CI 1.1-1.7), P = .02 and 1.9 (95% CI 1.5-2.4), P < .0001, respectively]. CONCLUSION: Isolation of enteric pathogens, rather than the polymicrobial character of the peritonitis, is associated with poorer outcomes.

Trends in Peritoneal Dialysis Technique Survival, Death, and Transfer to Hemodialysis: A Decade of Data from the RDPLF.

INTRODUCTION: There is limited information on the trends of peritoneal dialysis (PD) technique survival over time. This study aimed to estimate the effect of calendar time on technique survival, transfer to hemodialysis (HD) (and the individual causes of transfer), and patient survival. METHODS: This retrospective, multicenter study, based on data from the French Language Peritoneal Dialysis Registry, analyzed 14,673 patients who initiated PD in France between January 1, 2005, and December 31, 2016. Adjusted Cox regressions with robust variance were used to examine the probability of a composite end point of either death or transfer to HD, death, and transfer to HD, accounting for the nonlinear impact of PD start time. RESULTS: There were 10,201 (69.5%) cases of PD cessation over the study period: 5,495 (37.4%) deaths and 4,706 (32.1%) transfers to HD. The rate of PD cessation due to death or transfer to HD decreased over time (PR 0.96, 95% CI: 0.95-0.97). Compared to 2009-2010, starting PD between 2005 and 2008 or 2011 and 2016 was strongly associated with a lower rate of transfer to HD (PR 0.88, 95% CI: 0.81-0.96, and PR 0.91, 95% CI: 0.84-0.99, respectively), mostly due to a decline in the rate of infection-related transfers to HD (PR 0.96, 95% CI: 0.94-0.98). CONCLUSIONS: Rates of the composite end point of either death or transfer to HD, death, and transfer to HD have decreased in recent decades. The decline in transfers to HD rates, observed since 2011, is mainly the result of a significant decline in infection-related transfers.

Unilateral nephrectomy versus renal arterial embolization and technique survival in peritoneal dialysis patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disorder associated with progressive enlargement of the kidneys and liver. ADPKD patients may require renal volume reduction, especially before renal transplantation. The standard treatment is unilateral nephrectomy. However, surgery incurs a risk of blood transfusion and alloimmunization. Furthermore, when patients are treated with peritoneal dialysis (PD), surgery is associated with an increased risk of temporary or definitive switch to haemodialysis (HD). Unilateral renal arterial embolization can be used as an alternative approach to nephrectomy. METHODS: We performed a multicentre retrospective study to compare the technique of survival of PD after transcatheter renal artery embolization with that of nephrectomy in an ADPKD population. We included ADPKD patients treated with PD submitted to renal volume reduction by either surgery or arterial embolization. Secondary objectives were to compare the frequency and duration of a temporary switch to HD in both groups and the impact of the procedure on PD adequacy parameters. RESULTS: More than 700 patient files from 12 centres were screened. Only 37 patients met the inclusion criteria (i.e. treated with PD at the time of renal volume reduction) and were included in the study (21 embolized and 16 nephrectomized). Permanent switch to HD was observed in 6 embolized patients (28.6%) versus 11 nephrectomized patients (68.8%) (P = 0.0001). Renal artery embolization was associated with better technique survival: subdistribution hazard ratio (SHR) 0.29 [95% confidence interval (CI) 0.12-0.75; P = 0.01]. By multivariate analysis, renal volume reduction by embolization and male gender were associated with a decreased risk of switching to HD. After embolization, a decrease in PD adequacy parameters was observed but no embolized patients required temporary HD; the duration of hospitalization was significantly lower [5 days [interquartile range (IQR) 4.0-6.0] in the embolization group versus 8.5 days (IQR 6.0-11.0) in the surgery group. CONCLUSIONS: Transcatheter renal artery embolization yields better technique survival of PD in ADPKD patients requiring renal volume reduction.

Effects of educational practices on the peritonitis risk in peritoneal dialysis: a retrospective cohort study with data from the French peritoneal Dialysis registry (RDPLF).

BACKGROUND: Peritoneal dialysis (PD) is a home-based therapy performed by patients or their relatives in numerous cases, and the role of patients' educational practices in the risk of peritonitis is not well assessed. Our aim was to evaluate the effect of PD learning methods on the risk of peritonitis. METHODS: This was a retrospective multicentric study based on data from a French registry. All incident adults assisted by family or autonomous for PD exchanges in France between 2012 and 2015 were included. The event of interest was the occurrence of peritonitis. Cox and hurdle regression models were used for statistical analysis to asses for the survival free of peritonitis, and the risk of first and subsequent peritonitis. RESULTS: 1035 patients were included. 967 (93%) received education from a specialized nurse. Written support was used for the PD learning in 907 (87%) patients, audio support in 221 (21%) patients, and an evaluation grid was used to assess the comprehension in 625 (60%) patients. In the "zero" part of the hurdle model, the use of a written support and starting PD learning with hands-on training alone were associated with a lower survival free of peritonitis (respectively HR 1.59, 95%CI 1.01-2.5 and HR 1.94, 95%CI 1.08-3.49), whereas in the "count" part, the use of an audio support and starting of PD learning with hands-on training in combination with theory were associated with a lower risk of presenting further episodes of peritonitis after a first episode (respectively HR 0.55, 95%CI 0.31-0.98 and HR 0.57, 95%CI 0.33-0.96). CONCLUSIONS: The various PD education modalities were associated with differences in the risk of peritonitis. Prospective randomized trials are necessary to confirm causal effect. Caregivers should assess the patient's preferred learning style and their literacy level and adjust the PD learning method to each individual.

Impact of Assisted Peritoneal Dialysis Modality on Outcomes: A Cohort Study of the French Language Peritoneal Dialysis Registry.

BACKGROUND: Patients on peritoneal dialysis (PD) can be assisted by a nurse or a family member and treated either by automated PD (APD) or continuous ambulatory PD (CAPD). The aim of this study was to evaluate the effect of PD modality and type of assistance on the risk of transfer to haemodialysis (HD) and on the peritonitis risk in assisted PD patients. METHOD: This was a retrospective study based on data from the French Language PD Registry. All adults starting assisted PD in France between 2006 and 2015 were included. Events of interest were transfer to HD, peritonitis and death. Cox regression models were used for statistical analysis. RESULTS: Among the 12,144 incident patients who started PD in France during the study period, 6,167 were assisted. There were 5,060 nurse-assisted and 1,095 family-assisted PD patients. Overall, 5,171 were treated by CAPD and 996 by APD. In multivariate analysis, CAPD, compared to APD, was not associated with the risk of transfer to HD (cause specific hazard ratios [cs-HR] 0.96 [95% CI 0.84-1.09]). Patients on nurse-assisted PD had a lower risk of transfer to HD than family assisted PD patients (cs-HR 0.85 [95% CI 0.75-0.97]). Neither PD modality nor type of assistance were associated with peritonitis risk. CONCLUSIONS: In assisted PD, technique survival was not associated with PD modality. Nurse-assisted patients had a lower risk of transfer to HD than family assisted patients. Peritonitis risk was not influenced either by PD modality, or by type of assistance. Both APD and CAPD should be offered to assisted-PD patients.

Factors associated with nurse assistance among peritoneal dialysis patients: a cohort study from the French Language Peritoneal Dialysis Registry.

Background: No information is available regarding nurse-assisted peritoneal dialysis (PD) in non-elderly subjects. This study was carried out to estimate the rate of nurse-assisted PD among non-elderly patients and to assess which individual and centre factors were associated with nurse-assisted PD. The other objective was to estimate the magnitude of the centre effect on the utilization of nurse-assisted PD using hierarchical modelling. Methods: This was a retrospective study based on data from the French Language Peritoneal Dialysis Registry. Patients incident on PD > 18 and < 65 years of age were included. Results: There were 2269 incidents of PD initiation between January 2008 and December 2012 in 127 PD centres with 114 (5%) on family-assisted PD and 272 (12%) on nurse-assisted PD. At the individual level, compared with autonomous patients, nurse assistance was associated with age {odds ratio [OR] 1.79 [95% confidence interval (CI) 1.51-2.13]}, gender [OR 0.47 (95% CI 0.35-0.64)], comorbidities and underlying nephropathy. There was significant heterogeneity between centres in the nurse assistance utilization (variance of random effect 0.12). At the centre level, the type of centre, centre experience, centre organization and private nurse density were not associated with nurse-assisted PD. Conclusions: The rate of nurse-assisted PD among non-elderly patients was 12%. There was a significant centre effect in the utilization of nurse assistance that was not explained by the centres' characteristics. Nurse-assisted PD utilization in non-elderly patients is associated with patient characteristics and also with centre practices.

Outcome of autosomal dominant polycystic kidney disease patients on peritoneal dialysis: a national retrospective study based on two French registries (the French Language Peritoneal Dialysis Registry and the French Renal Epidemiology and Information Network).

Background: Pathological features of autosomal dominant polycystic kidney disease (ADPKD) include enlarged kidney volume, higher frequency of digestive diverticulitis and abdominal wall hernias. Therefore, many nephrologists have concerns about the use of peritoneal dialysis (PD) in ADPKD patients. We aimed to analyse survival and technique failure in ADPKD patients treated with PD. Methods: We conducted two retrospective studies on patients starting dialysis between 2000 and 2010. We used two French registries: the French Renal Epidemiology and Information Network (REIN) and the French language Peritoneal Dialysis Registry (RDPLF). Using the REIN registry, we compared the clinical features and outcomes of ADPKD patients on PD (n = 638) with those of ADPKD patients on haemodialysis (HD) (n = 4653); with the RDPLF registry, those same parameters were determined for ADPKD patients on PD (n = 797) and compared with those of non-ADPKD patients on PD (n = 12 059). Results: A total of 5291 ADPKD patients and 12 059 non-ADPKD patients were included. Analysis of the REIN registry found that ADPKD patients treated with PD represented 10.91% of the ADPKD population. During the study period, PD was used for 11.2% of the non-ADPKD population. Compared with ADPKD patients on HD, ADPKD patients on PD had higher serum albumin levels (38.8 ± 5.3 versus 36.8 ± 5.7 g/dL, P < 0.0001) and were less frequently diabetic (5.31 versus 7.71%, P < 0.03). The use of PD in ADPKD patients was positively associated with the occurrence of a kidney transplantation but not with death [hazard ratio 1.15 (95% confidence interval 0.84-1.58)]. Analysis of the RDPLF registry found that compared with non-ADPKD patients on PD, ADPKD patients on PD were younger and had fewer comorbidities and better survival. ADPKD status was not associated with an increased risk of technique failure or an increased risk of peritonitis. Conclusions: According to our results, PD is proposed to a selected population of ADPKD patients, PD does not have a negative impact on ADPKD patients' overall survival and PD technique failure is not influenced by ADPKD status. Therefore PD is a reasonable option for ADPKD patients.

Centre characteristics associated with the risk of peritonitis in peritoneal dialysis: a hierarchical modelling approach based on the data of the French Language Peritoneal Dialysis Registry.

BACKGROUND.: This study investigated the centre effect on the risk of peritonitis in peritoneal dialysis (PD) patients. METHODS.: This was a retrospective cohort study based on data from the French Language Peritoneal Dialysis Registry. We analysed 5017 incident patients starting PD between January 2008 and December 2012 in 127 PD centres. The end of the observation period was 1 January 2014. The event of interest was the first peritonitis episode. The analysis was performed with a multilevel Cox model and a Fine and Gray model. RESULTS.: Among the 5017 patients, 3190 peritonitis episodes occurred in 1796 patients. There was significant heterogeneity between centres (variance of the random effect: 0.11). The variance of the centre effect was reduced by 9% after adjusting for patient characteristics and by 35% after adjusting on centre covariate. In the multivariate analysis with a multilevel Cox model, centre with a nurse specialized in PD or centre providing home visits before dialysis initiation decreased the centre effect on peritonitis. Patients treated in centres with a nurse specialized in PD or in centres providing home visits before dialysis initiation had a lower risk of peritonitis [cause-specific hazard ratio (cs-HR): 0.75 (95% confidence interval, CI, 0.67-0.83) and cs-HR: 0.87 (95% CI 0.76-0.97), respectively]. The data show that neither centre type nor centre volume influenced peritonitis risk. In the competing risk analysis, centre with a nurse specialized in PD and centre with home visits had a protective effect on peritonitis [sub-distribution HR (sd-HR): 0.77 (95% CI 0.70-0.85) and sd-HR: 0.85 (95% CI 0.77-0.94), respectively]. CONCLUSION.: There is a significant centre effect on the risk of peritonitis that can be decreased by home visits before dialysis initiation and by the presence of a nurse specialized in PD.

Efficacy of Prophylactic Antibiotics at Peritoneal Catheter Insertion on Early Peritonitis: Data from the Catheter Section of the French Language Peritoneal Dialysis Registry.

BACKGROUND: International guidelines recommend the use of a prophylactic antibiotic before the peritoneal dialysis (PD) catheter can be inserted. The main objective of this study was to assess whether this practice is associated with a lower risk of early peritonitis and to estimate the magnitude of the centre effect. METHODS: A retrospective, multi-centric study was conducted, in which data from the French Language Peritoneal Dialysis Registry was analysed. Patients were separated into 2 groups based on whether or not prophylactic antibiotics were used prior to catheter placement. RESULTS: Out of the 2,014 patients who had a PD catheter placed between February 1, 2012 and December 31, 2014, 1,105 were given a prophylactic antibiotic. In a classical logit model, the use of prophylactic antibiotics was found to protect the individual against the risk of early peritonitis (OR 0.67, 95% CI 0.49-0.92). However, this association lost significance in a mixed logistic regression model with centre as a random effect: OR 0.73 (95% CI 0.48-1.09). Covariates associated with the risk of developing early peritonitis were age over 65: OR 0.73 (95% CI 0.39-0.85), body mass index over 35 kg/m2: OR 1.99 (95% CI 1.13-3.47), transfer to PD due to graft failure: OR 2.24 (95% CI 1.22-4.11), assisted PD: OR 1.96 (95% CI 1.31-2.93), and the use of the Moncrief technique: OR 3.07 (95% CI 1.85-5.11). CONCLUSION: There is a beneficial effect of prophylactic antibiotic used prior to peritoneal catheter placement, on the occurence of early peritonitis. However, the beneficial effect could be masked by a centre effect.

Effect of assistance on peritonitis risk in diabetic patients treated by peritoneal dialysis: report from the French Language Peritoneal Dialysis Registry.

BACKGROUND: Diabetic patients treated by peritoneal dialysis (PD) have been reported to be at an increased risk of peritonitis. This has been attributed to impairment in host defense, visual impairment, disability and muscle wasting, which could compromise ability to safely perform catheter connections. This study aimed to evaluate whether assisted PD is associated with a lower risk of peritonitis in diabetic patients. METHODS: This was a retrospective study based on data from the French Language Peritoneal Dialysis Registry. We included diabetic patients starting PD between 1 January 2002 and 31 December 2012. The end of the observation period was 31 December 2013. Using complementary regression analysis (Fine and Gray, Hurdle models), we assessed the relationship between peritonitis occurrence, peritonitis number over time and the type of assisted PD. RESULTS: Of the 3598 diabetic patients, there were 2040 patients on nurse-assisted PD. These patients were older, more comorbid and more frequently on continuous ambulatory peritoneal dialysis (CAPD). In the multivariate analysis, nurse assistance was associated with a reduced risk of peritonitis in the Fine and Gray [subdistribution hazard ratio: 0.78 (95% confidence interval, CI, 0.68-0.89)] and in the first component of the Hurdle models [rate ratio: 0.82 (95% CI 0.71-0.93)], but not a lower incidence of peritonitis after an initial episode [rate ratio: 0.82 (95% CI 0.95-1.38)]. Transplant failure, glomerulonephritis and CAPD were associated with an increased risk. CONCLUSIONS: In France, nurse-assisted PD is associated with a lower risk of peritonitis in diabetic patients treated by PD but not a lower incidence of peritonitis.

Baseline hydration status in incident peritoneal dialysis patients: the initiative of patient outcomes in dialysis (IPOD-PD study)†.

BACKGROUND: Non-euvolaemia in peritoneal dialysis (PD) patients is associated with elevated mortality risk. There is an urgent need to collect data to help us understand the association between clinical practices and hydration and nutritional status, and their effects on patient outcome. METHODS: The aim of this prospective international, longitudinal observational cohort study is to follow up the hydration and nutritional status, as measured by bioimpedance spectroscopy using the body composition monitor (BCM) of incident PD patients for up to 5 years. Measures of hydration and nutritional status and of clinical, biochemical and therapy-related data are collected directly before start of PD treatment, at 1 and 3 months, and then every 3 months. This paper presents the protocol and a pre-specified analysis of baseline data of the cohort. RESULTS: A total of 1092 patients (58.1% male, 58.0 ± 15.3 years) from 135 centres in 32 countries were included. Median fluid overload (FO) was 2.0 L (males) and 0.9 L (females). Less than half of the patients were normohydrated (38.7%), whereas FO > 1.1 L was seen in 56.5%. Systolic and diastolic blood pressure were 139.5 ± 21.8 and 80.0 ± 12.8 mmHg, respectively, and 25.1% of patients had congestive heart failure [New York Heart Association (NYHA) 1 or higher]. A substantial number of patients judged to be not overhydrated on clinical judgement appeared to be overhydrated by BCM measurement. Overhydration at baseline was independently associated with male gender and diabetic status. CONCLUSIONS: The majority of patients starting on PD are overhydrated already at start of PD. This may have important consequences on clinical outcomes and preservation of residual renal function. Substantial reclassification of hydration status by BCM versus on a clinical basis was necessary, especially in patients who were not overtly overhydrated. Both clinical appreciation and bioimpedance should be combined in clinical decision-making on hydration status.

Early failure in patients starting peritoneal dialysis: a competing risks approach.

BACKGROUND: Technical failure is more likely to occur in the first 6 months of peritoneal dialysis (PD). This study was carried out to identify risk factors for early transfer from PD to haemodialysis (HD) in a country where assisted PD is available. METHODS: All patients from the French Language Peritoneal Dialysis Registry (RDPLF) who started PD between 1 January 2002 and 31 December 2010 were included. Time to transfer, death and transplantation during the first 6 months on PD were analysed by the multivariate Cox proportional hazard model. The Fine and Gray model was used to examine the occurrence of technical failure by considering death and transplantation as competing events. RESULTS: Of 9675 patients included, 615 (6.3%) moved to HD during the first 6 months of PD. Cumulative incidence of transfer to HD was 6.6% at 6 months. On multivariate analysis by both the Cox model and the Fine and Gray model, HD prior to PD, allograft failure and early peritonitis were associated with a higher risk of early technical failure, whereas being dialysed in a centre treating more than 20 new patients per year was associated with a lower risk of early transfer to HD. CONCLUSIONS: Patients treated by HD before PD and failed transplant patients had a higher risk of early PD failure when competing events were considered.

Outcome of the sub-optimal dialysis starter on peritoneal dialysis. Report from the French Language Peritoneal Dialysis Registry (RDPLF).

BACKGROUND: This study was carried out to examine the association of sub-optimal dialysis initiation of peritoneal dialysis (PD) with all the possible outcomes on PD using survival analysis in the presence of competing risks. METHODS: This was a retrospective cohort study based on the data of the French Language Peritoneal Dialysis Registry. We analysed 8527 incident patients starting PD between January 2002 and December 2010. The end of the observation period was 01 June 2011. Times from the start of PD to death, transplantation, transfer to haemodialysis (HD) and first peritonitis episode were calculated. The sub-optimal dialysis initiation was defined by a period of <30 days on HD before PD initiation. RESULTS: Among 8527 patients, there were 568 patients who started PD after <30 days on HD. There were 6562 events: 3078 deaths, 2136 transfers to HD, 1348 renal transplantations. When using a Fine and Gray model, sub-optimal dialysis start, early peritonitis and transplant failure were associated with a higher sub-distribution relative hazard of technique failure. There was no association between the sub-optimal dialysis start and the sub-distribution hazard of death or transplantation. In the multivariate analysis using a Fine and Gray regression model, the sub-optimal dialysis start was not associated with a higher sub distribution relative hazard of peritonitis. CONCLUSIONS: Sub-optimal dialysis initiation is neither associated with a higher risk of death nor with a lower risk of renal transplantation. Sub-optimal PD patients had a higher risk of transfer to HD.

A multicentric, international matched pair analysis of body composition in peritoneal dialysis versus haemodialysis patients.

BACKGROUND: Volume status, lean and fat tissue are gaining interest as prognostic predictors in patients on dialysis. Comparative data in peritoneal dialysis (PD) versus haemodialysis (HD) patients are lacking. METHODS: In a cohort of PD (EuroBCM) and HD (Euclid database) patients, matched for country, gender, age and dialysis vintage, body composition was assessed by bioimpedance spectroscopy (BCM, Fresenius Medical Care). Time-averaged volume overload (TAVO) was defined as the mean of pre- and post-dialysis volume overload (VO), and relative (%) (TA)VO as (TA)VO/ECV. RESULTS: Four hundred and ninety-one matched pairs (55.2% males, median age 60.0 years) were included. The body mass index (BMI, PD = 26.5 ± 4.7 versus HD = 25.9 ± 4.6 kg/m(2), P = 0.18 in males and 27.4 ± 5.8 versus 27.5 ± 6.6 kg/m(2), P = 0.75 in females) and fat tissue index (males: 11.5 ± 5.3 versus 11.4 ± 5.4 kg/m(2), P = 0.90, females: 14.8 ± 6.7 versus 15.4 ± 7.2 kg/m(2), P = 0.30) were not different in PD versus HD patients, whereas the lean tissue index (LTI) was higher in PD versus HD patients (males: 14.5 ± 3.4 versus 13.7 ± 3.1 kg/m(2), P = 0.001, females: 12.6 ± 3.3 versus 11.5 ± 2.6 kg/m(2), P < 0.0001). VO/extracellular water (ECW) was not different between PD versus just before the HD treatment (males: 10.8 ± 12.1 versus 9.2 ± 10.2%, P = 0.09; females: 6.5 ± 10.8 versus 7.7 ± 9.4%, P = 0.19). The relative TAVO was higher in PD versus HD (10.8 ± 12.1% versus 3.2 ± 11.2%, and 6.5 ± 10.8% versus 1.2 ± 10.9%, both P < 0.0001). CONCLUSIONS: The LTI was impaired, and this was more in males versus females, but was better preserved on PD versus HD, whereas fat tissue index (FTI) was increased, but not different between PD and HD. Volume overload was more present in PD versus HD when TAVO, but not when predialysis volume status, was used as a reference.

Simplified calculation of peritoneal dialysis-associated peritonitis rate: Accuracy of a recently developed estimating equation.

Recently, we validated a simple method for estimating peritoneal dialysis (PD) peritonitis rate. Despite good agreement between estimates and gold-standard measurements in two large dialysis registries, the International Society of Peritoneal Dialysis (ISPD) was hesitant to recommend adoption of the estimating equation. Their perception is that inaccuracies, as small as they are, might still be detrimental to clinical decision-making. In this study, we apply new analyses to the original validation data sets. We quantify agreement using standards from the International Organization for Standardization (ISO). We also identify a subset of centres with poorest performance of the estimating equation and qualitatively assess the potential for compromised clinical decision-making associated with its use. Inter-assay % coefficient of variation between estimates and measurements was 4.2% in the Australia and New Zealand Dialysis and Transplant Registry and 4.6% in Le Registre de Dialyse Péritonéale de Langue Française, easily meeting ISO requirements. Mandel's h values and Grubb's tests confirmed more outlying estimates compared to the measurements, while Mandel's k values and Cochran's C tests showed that identical precision by the two methods. Misclassification of centres as being above versus below the ISPD standard of 0.4 episodes/patient-year occurred only with rates close to the threshold, affecting approximately 3% of patient-years. In the 26 (out of 268) centres with poorest performance of the estimating equation, examination of the time series of their annual PD peritonitis rate estimates/measurements showed that using estimates would not detrimental to clinical decision-making. In conclusion, the estimating equation is sufficiently accurate for routine clinical use.

Combining directed acyclic graphs and the change-in-estimate procedure as a novel approach to adjustment-variable selection in epidemiology.

BACKGROUND: Directed acyclic graphs (DAGs) are an effective means of presenting expert-knowledge assumptions when selecting adjustment variables in epidemiology, whereas the change-in-estimate procedure is a common statistics-based approach. As DAGs imply specific empirical relationships which can be explored by the change-in-estimate procedure, it should be possible to combine the two approaches. This paper proposes such an approach which aims to produce well-adjusted estimates for a given research question, based on plausible DAGs consistent with the data at hand, combining prior knowledge and standard regression methods. METHODS: Based on the relationships laid out in a DAG, researchers can predict how a collapsible estimator (e.g. risk ratio or risk difference) for an effect of interest should change when adjusted on different variable sets. Implied and observed patterns can then be compared to detect inconsistencies and so guide adjustment-variable selection. RESULTS: The proposed approach involves i. drawing up a set of plausible background-knowledge DAGs; ii. starting with one of these DAGs as a working DAG, identifying a minimal variable set, S, sufficient to control for bias on the effect of interest; iii. estimating a collapsible estimator adjusted on S, then adjusted on S plus each variable not in S in turn ("add-one pattern") and then adjusted on the variables in S minus each of these variables in turn ("minus-one pattern"); iv. checking the observed add-one and minus-one patterns against the pattern implied by the working DAG and the other prior DAGs; v. reviewing the DAGs, if needed; and vi. presenting the initial and all final DAGs with estimates. CONCLUSION: This approach to adjustment-variable selection combines background-knowledge and statistics-based approaches using methods already common in epidemiology and communicates assumptions and uncertainties in a standardized graphical format. It is probably best suited to areas where there is considerable background knowledge about plausible variable relationships. Researchers may use this approach as an additional tool for selecting adjustment variables when analyzing epidemiological data.

Characteristics, practices, and outcomes in a Belgian cohort of incident home hemodialysis patients: A 6-year experience.

BACKGROUND: Home hemodialysis (HHD) remains underused in patients with kidney failure. Current literature on HHD mostly originates from non-European countries, making generalization difficult. The present study describes patients' profile and practice patterns from a Belgian HHD center, and assesses patient and technique survival and complications associated with HHD. METHODS: We analyzed data from all our incident patients during a 6-year period. The patient's characteristics were summarized using descriptive statistics. Transition to another therapeutic modality, estimated using a risk model with death and transplantation as competing events, episodes of respite cares and hospitalizations, and access complications were analyzed. RESULTS: Eighty patients (mean age: 47 years; male: 64%) met the inclusion criteria. Fifty-one percent of patients initiated dialysis with a central venous catheter (CVC) and 96% were not assisted. Arterio-venous fistula (AVF) cannulation was performed using buttonhole technique. Standard-frequent HD (47%) and short-frequent low-flow dialysate HD (34%) were mostly used at HHD initiation. Cumulative incidences of technique failure and death were 15%, 24%, and 32% at 1, 2, and 5 years. Incidence rates for respite dialysis and hospitalizations were 2.39 and 0.54 per patient-year of HHD. In comparison with AVF, incidence rate ratios of overall access complications and access-related infections for CVC were 4.3 (95% CI: 3.1-6, p < 0.01) and 4.4 (95% CI: 2.1-10, p < 0.01), respectively. Buttonhole cannulation was complicated by 0.26 (95% CI: 0.15-0.46) infections per 1000 AVF-days. CONCLUSIONS: This present study provides important information about patient's profile and practice patterns and safety in a cohort of 80 incident Belgian HHD patients, with encouraging techniques and patient survival.

Peritoneal dialysis in polycystic kidney disease patients. Report from the French peritoneal dialysis registry (RDPLF).

BACKGROUND: It is commonly believed that polycystic kidney disease (PKD) patients on peritoneal dialysis (PD) are over-exposed to technique failure and peritonitis compared with other patients. This study was carried out to assess whether PKD is associated with technique failure and to evaluate the outcome of PKD patients on PD. METHODS: This was a retrospective cohort study based on the data of the French Language Peritoneal Dialysis Registry. We analysed 4162 incident non-diabetic patients who started PD between January 2002 and December 2007. The end of the observation period was 31 December 2008. RESULTS: Among 4162 patients, there were 344 PKD patients and 3818 patients who had another underlying nephropathy. PKD patients were younger, had a lower Charlson comorbidity index, were more frequently treated by automated PD and were less frequently assisted than other patients. For the PKD patients, the main reason for PD cessation was renal transplantation. In the multivariate analysis, comorbidities and centre size were associated with technique survival, and no association between PKD and technique failure was observed. There was no statistically significant association between PKD and peritonitis or between PKD and enteric peritonitis. On multivariate analysis, patient survival was associated with PKD and with patient age, comorbidities and the modality of assistance. Centre size was not associated with patient survival. CONCLUSION: PD is a suitable method for at least a subgroup of PKD patients reaching end-stage renal disease in a country where renal transplantation is available.

[Prevalence and risk factors of attention disorders of professional drivers in Morocco]. / Prévalences et facteurs de risque des troubles de la vigilance chez les routiers professionnels au Maroc.

We aimed to evaluate the prevalence and risk factors of professional drivers' vigilance disorders in Morocco. This transversal epidemiological multicentric study concerned 5,566 professional drivers of taxis (2,134), buses (1,158) and trucks (2,274). We used an anonymous individual questionnaire of 4 sections: socioprofessional and sanitary characteristics of drivers, working conditions, sleeping habits, symptoms of sleep problems and favouring factors. Drivers were a population at risk: high body mass index (62.2%), toxic habits (smoking: 50.6%; alcohol: 12.9%; cannabis use: 11.7%), pathological antecedents (27%) and consumption of psychotropic drugs (4%). Their working conditions were difficult and sleeping problems were frequent. The mean daily hours of work was 10.6 ± 1.6, and mean sleep duration 6.5 ± 1.3 hr. Insomnia was 40.2%, abnormally high Epworth scores 36.3% and sleepiness when driving 53.4%. Information and education on the dangers of sleepiness while driving is necessary, as is respect for regulations on work duration. The extension of the occupational health system to this type of activity would help improve road security and protect the health of professional drivers and road users.

Association of Prescription With Body Composition and Patient Outcomes in Incident Peritoneal Dialysis Patients.

Objective: The nutritional status of patients on peritoneal dialysis (PD) is influenced by patient- and disease-related factors and lifestyle. This analysis evaluated the association of PD prescription with body composition and patient outcomes in the prospective incident Initiative for Patient Outcomes in Dialysis-Peritoneal Dialysis (IPOD-PD) patient cohort. Design and Methods: In this observational, international cohort study with longitudinal follow-up of 1,054 incident PD patients, the association of PD prescription with body composition was analyzed by using the linear mixed models, and the association of body composition with death and change to hemodialysis (HD) by means of a competing risk analysis combined with a spline analysis. Body composition was regularly assessed with the body composition monitor, a device applying bioimpedance spectroscopy. Results: Age, time on PD, and the use of hypertonic and polyglucose solutions were significantly associated with a decrease in lean tissue index (LTI) and an increase in fat tissue index (FTI) over time. Competing risk analysis revealed a U-shaped association of body mass index (BMI) with the subdistributional hazard ratio (HR) for risk of death. High LTI was associated with a lower subdistributional HR, whereas low LTI was associated with an increased subdistributional HR when compared with the median LTI as a reference. High FTI was associated with a higher subdistributional HR when compared with the median as a reference. Subdistributional HR for risk of change to HD was not associated with any of the body composition parameters. The use of polyglucose or hypertonic PD solutions was predictive of an increased probability of change to HD, and the use of biocompatible solutions was predictive of a decreased probability of change to HD. Conclusion: Body composition is associated with non-modifiable patient-specific and modifiable treatment-related factors. The association between lean tissue and fat tissue mass and death and change to HD in patients on PD suggests developing interventions and patient counseling to improve nutritional markers and, ultimately, patient outcomes. Study Registration: The study has been registered at Clinicaltrials.gov (NCT01285726).