Pregnancy Among Women Receiving Chronic Dialysis in France (2006-2020).

Introduction: In women receiving chronic dialysis, fertility is impaired. The objectives of this study were to estimate the incidence rate of pregnancies among women of childbearing age (15-50 years) receiving chronic dialysis from 2006 to 2020 in France, to describe the pregnancy outcomes and renal management during pregnancy. Methods: This national observational, retrospective study was based on data from the French REIN registry matched with the National Health Data System. Results: Over the period 2006 to 2020 in France, 348 pregnancies were identified in 240 women receiving chronic dialysis. The overall incidence of pregnancy was 11.1, 95% confidence interval (CI) (9.9-12.3) cases per 1000 person-years. Hemodialysis was the predominant modality during pregnancy. Main maternal complications were preeclampsia (n = 19) and gestational diabetes (n = 11). The most obstetric complications were premature rupture of membranes (n = 14) and polyhydramnios (n = 5). These pregnancies resulted in 174 (50%) abortions (<22 weeks), including 104 elective abortions (29.9%), 44 miscarriages (12.6%), 17 therapeutic abortions (4.9%), 5 ectopic pregnancies (1.4%), and 4 hydatidiform moles (1.2%). The remaining 174 (50%) pregnancies with deliveries (≥22 weeks) resulted in 166 live births (70 full-term [42.2%], 96 preterm births [57.8%]), and 8 stillbirths. Median gestational age was 36 weeks (32-38) for 174 deliveries. Conclusion: There have been improvements in maternal and fetal outcomes regarding pregnancy on chronic dialysis. However, our study shows a significant proportion of elective abortions. Better fertility management of women receiving chronic dialysis is advised by contraception or by pregnancy planning and early multidisciplinary follow-up.

Multiple air pollutant exposure is associated with higher risk of all-cause mortality in dialysis patients: a French registry-based nationwide study.

Background: Little is known about the effect of combined exposure to different air pollutants on mortality in dialysis patients. This study aimed to investigate the association of multiple exposures to air pollutants with all-cause and cause-specific death in dialysis patients. Materials and methods: This registry-based nationwide cohort study included 90,373 adult kidney failure patients initiating maintenance dialysis between 2012 and 2020 identified from the French REIN registry. Estimated mean annual municipality levels of PM2.5, PM10, and NO2 between 2009 and 2020 were combined in different composite air pollution scores to estimate each participant's exposure at the residential place one to 3 years before dialysis initiation. Adjusted cause-specific Cox proportional hazard models were used to estimate hazard ratios (HRs) per interquartile range (IQR) greater air pollution score. Effect measure modification was assessed for age, sex, dialysis care model, and baseline comorbidities. Results: Higher levels of the main air pollution score were associated with a greater rate of all-cause deaths (HR, 1.082 [95% confidence interval (CI), 1.057-1.104] per IQR increase), regardless of the exposure lag. This association was also confirmed in cause-specific analyses, most markedly for infectious mortality (HR, 1.686 [95% CI, 1.470-1.933]). Sensitivity analyses with alternative composite air pollution scores showed consistent findings. Subgroup analyses revealed a significantly stronger association among women and fewer comorbid patients. Discussion: Long-term multiple air pollutant exposure is associated with all-cause and cause-specific mortality among patients receiving maintenance dialysis, suggesting that air pollution may be a significant contributor to the increasing trend of CKD-attributable mortality worldwide.

Effect of Hydroxychloroquine Treatment on Kidney Allograft Rejection and Graft Failure.

Kidney allograft rejection is a major issue because it causes graft failure and because immunosuppressive treatments used for its prevention increase the risk of infections and cancers. In systemic lupus patients, hydroxychloroquine is used to prevent immune flares with decreased doses of immunosuppressants. Hydroxychloroquine can be safely used in kidney transplant recipients when indicated for autoimmune disease, but its effect on allograft rejection is unknown. We hypothesized that it may prevent kidney allograft rejection. We conducted a nationwide retrospective propensity-matched study on kidney transplantations of patients treated with hydroxychloroquine in France between 2008 and 2018. We analyzed the incidence of allograft rejection or failure within the first year after transplantation. The rates of rejection or allograft failure were not different between the 188 patients treated with hydroxychloroquine at the time of transplantation and their propensity matched controls. Hydroxychloroquine treatment in association with standard immunosuppressive treatment does not prevent rejection in kidney allograft recipients.

Experience of Chronic Kidney Disease and Perceptions of Transplantation by Sex.

Importance: The pathway to kidney transplantation (KT) begins with the patient's acceptance of this surgical procedure after discussion with the nephrologist. The patients' perceptions of the disease and of KT may influence their willingness to undergo transplantation. Objective: To describe patients' experiences of kidney disease and their perceptions of KT and the nephrologists' perceptions of the patient experience. Design, Setting, and Participants: This qualitative study collected data through semistructured interviews with patients with chronic kidney disease and nephrologists in the Bretagne, Île-de-France and Normandie regions, France. Researchers involved in the study in each region purposely selected 99 patients with chronic kidney disease who initiated dialysis in 2021, based on their age, sex, dialysis facility ownership, and also 45 nephrologists, based on their sex and years of experience. Data analysis was performed from January to October 2023. Main Outcomes and Measures: Themes were identified using inductive thematic analysis. Specific characteristics of men and women as well as the nephrologist's views for each theme were described. Results: This study included 42 men and 57 women (56 [57%] aged 60 years or older) who started dialysis in 2021 and 45 nephrologists (23 women and 22 men). Six major themes were identified: (1) burden of chronic kidney disease on patients and their families, (2) health care professional-patient relationship and other factors that modulate chronic kidney disease acceptance, (3) dialysis perceived as a restrictive treatment, (4) patients' representation of the kidney graft, (5) role of past experiences in KT perception, and (6) dualistic perception of KT. In some cases, women and nephrologists indicated that women's perceptions and experiences were different than men's; for example, the disease's psychological impact and the living donor KT refusal were mainly reported by 8 women. Conclusions and Relevance: Patients' past experience of chronic kidney disease in general and of KT in particular, as well as their relationship with their family and nephrologist, were substantial determinants of KT perception in this qualitative study. Targeted policies on these different factors might help to improve access to KT, and more research is needed to understand whether there are sex-based disparities.

Social Deprivation and Incidence of Pediatric Kidney Failure in France.

Introduction: Approximately 8 per million children and young adults aged < 20 years initiate kidney replacement therapy (KRT) per year in France. We hypothesize that social deprivation could be a determinant of childhood-onset kidney failure. The objective of this study was to estimate the incidence of pediatric KRT in France according to the level of social deprivation. Methods: All patients < 20 years who initiated KRT from 2010 to 2015 in metropolitan France were included. Data were collected from the comprehensive French registry of KRT French Renal Epidemiology and Information network (REIN). We used a validated ecological index to assess social deprivation, the 2011 French version of the European Deprivation Index (EDI). We estimated the age standardized incidence rates according to the quintiles of EDI using direct standardization and incidence rate ratio using Poisson regression. Results: We included 672 children with kidney failure (58.6% males, 30.7% with glomerular or vascular disease, 43.3% starting KRT between 11 and 17 years). 38.8% were from the most deprived areas (quintile 5 of EDI). The age standardized incidence rate increased with quintile of EDI, from 5.45 (95% confidence interval [CI] = 4.25-6.64) per million children per year in the least deprived quintile to 8.46 (95% CI = 7.41-9.51) in the most deprived quintile of EDI (incidence rates ratio Q5 vs. Q1 1.53-fold; 95% CI = 1.18-2.01). Conclusion: This study showed that even in a country with a universal health care system, there is a strong association between the incidence of pediatric KRT and social deprivation showing that social health inequalities appear from KRT initiation. This study highlights the need to look further into social inequalities in the earliest stage of chronic kidney disease (CKD).

Transfers from home to facility-based dialysis: comparisons of HHD, assisted PD and autonomous PD.

Background: Home dialysis therapies such as peritoneal dialysis (PD) and home hemodialysis (HHD) are beneficial for quality of life and patient empowerment. The short technique survival time partly explains their low prevalence. We aimed to assess the risk of transfer to facility-based hemodialysis in patients treated with autonomous PD, assisted PD and HHD. Methods: This was a retrospective study using data from the REIN registry of patients starting home dialysis in France from 2002 to 2019. The risks of transfer to facility-based hemodialysis (HD) were compared between three modalities of home dialysis (HHD, nurse-assisted PD, autonomous PD) using survival models with a propensity score (PS)-matched and unmatched cohort of patients. Results: The study included 17 909 patients: 628 in the HHD group, 10 214 in the autonomous PD group, and 7067 in the assisted PD group. During the follow-up period, there were 5347 transfers to facility-based HD. The observed number of transfers was 2458 (13.7%) at 1 year and 5069 (28.3) at 5 years after the start of home dialysis, including 3272 (32%) on autonomous PD, 1648 (23.3%) on assisted PD, and 149 (23.7) on HHD. Owing to clinical characteristics differences, only 38% of HHD patients could be matched to patients from the others group. In the PS-matched cohort, the adjusted Cox model showed no difference in the risk of transfer for assisted PD (cs-HR 1.04, 95% CI 0.75-1.44) or HHD (cs-HR 1.07, 95% CI 0.77-1.48) compared with autonomous PD. Conclusions: Unlike results from other countries, where nurse assistance is not fully available for PD-associated care, there was no difference in technique survival between autonomous PD, nurse-assisted PD, and HHD in France. This discrepancy may be attributed to our inclusion of a broader spectrum of patients who derive significant benefits from assisted PD.

Time trends in preemptive kidney transplantation in Europe: an era registry study.

BACKGROUND: Preemptive kidney transplantation has better outcomes when compared to transplantation after dialysis. We aimed to examine trends in preemptive kidney transplantation between 2000 and 2019 in Europe and to provide an overview of associated policies, barriers and initiatives. METHODS: Adult patients from 12 European countries who received a preemptive kidney transplant were included. The representatives of the registries providing these data were questioned on the policies, barriers and initiatives around preemptive kidney transplantation. RESULTS: Between 2000 and 2019, 20 251 adults underwent preemptive kidney transplantation (11 169 from living donors, 8937 from deceased donors). The proportion of first kidney transplantations that were preemptive more than doubled from 7% in 2000 to 18% in 2019, reflecting a similar relative increase for living donor kidney recipients (from 21% to 43%) and deceased donor kidney recipients (from 4% to 11%). Large international differences were found. The increase in preemptive kidney transplantation was observed across all age, sex and primary renal disease groups. Countries had similar criteria for preemptive waitlisting. Barriers mentioned included donor shortage, late referral to the transplant center and long donor or recipient work-up. Suggested initiatives included raising awareness on the possibility of preemptive kidney transplantation, earlier start and shorter work-up time for recipient and living donor. CONCLUSIONS: Over the last two decades the proportion of patients receiving a first kidney transplant preemptively has more than doubled, reflecting a similar relative increase for living and deceased donor kidney recipients.

Prevalence of chronic kidney disease in France: methodological considerations and pitfalls with the use of Health claims databases.

Background: Health policy-making require careful assessment of chronic kidney disease (CKD) epidemiology to develop efficient and cost-effective care strategies. The aim of the present study was to use the RENALGO-EXPERT algorithm to estimate the global prevalence of CKD in France. Methods: An expert group developed the RENALGO-EXPERT algorithm based on healthcare consumption. This algorithm has been applied to the French National Health claims database (SNDS), where no biological test findings are available to estimate a national CKD prevalence for the years 2018-2021. The CONSTANCES cohort (+219 000 adults aged 18-69 with one CKD-EPI eGFR) was used to discuss the limit of using health claims data. Results: Between 2018 and 2021, the estimated prevalence in the SNDS increased from 8.1% to 10.5%. The RENALGO-EXPERT algorithm identified 4.5% of the volunteers in the CONSTANCES as CKD. The RENALGO-EXPERT algorithm had a positive predictive value of 6.2% and negative predictive value of 99.1% to detect an eGFR<60 ml/min/1.73 m². Half of 252 false positive cases (ALGO+, eGFR > 90) had been diagnosed with kidney disease during hospitalization, and the other half based on healthcare consumption suggestive of a 'high-risk' profile; 95% of the 1661 false negatives (ALGO-, eGFR < 60) had an eGFR between 45 and 60 ml/min, half had medication and two-thirds had biological exams possibly linked to CKD. Half of them had a hospital stay during the period but none had a diagnosis of kidney disease. Conclusions: Our result is in accordance with other estimations of CKD prevalence in the general population. Analysis of diverging cases (FP and FN) suggests using health claims data have inherent limitations. Such an algorithm can identify patients whose care pathway is close to the usual and specific CKD pathways. It does not identify patients who have not been diagnosed or whose care is inappropriate or at early stage with stable GFR.

Is social deprivation associated with the peritoneal dialysis outcomes? A cohort study with REIN registry data.

BACKGROUND: Social deprivation is associated with lower peritoneal dialysis (PD) uptake. This study was carried out to evaluate the role of social deprivation on the outcome of PD. METHODS: This was a retrospective study of data extracted from the Renal Epidemiology and Information Network registry for patients older than 18 years who started PD in metropolitan France between 1 January 2017 and 30 June 2018. The end of the observation period was 31 December 2020. The exposure was the European Deprivation Index calculated using the patient's address. The events of interest were death, transfer to haemodialysis (HD), transplantation and the composite event of death or transfer to HD. A Cox model and Fine and Gray model were used for the analysis. RESULTS: A total of 1581 patients were included, of whom 418 (26.5%) belonged to Quintile 5 of the European Deprivation Index (the most deprived patients). In the Cox model, the most deprived subjects did not have a greater risk of death (cause-specific hazard ratio (cs-HR): 0.76 [95% confidence interval (CI): 0.53-1.10], transfer to HD (cs-HR 1.37 [95% CI: 0.95-1.98]) or the composite event of death or transfer to HD (cs-HR: 1.08 [95% CI: 0.84-1.38]) or a lower risk of kidney transplantation (cs-HR: 0.73 [95% CI: 0.48-1.10]). In the competing risk analysis, the most deprived subjects had a higher risk of transfer to HD (subdistribution hazard ratio (sd-HR): 1.54 [95% CI: 1.08-2.19]) and lower access to kidney transplantation (sd-HR: 0.68 [0.46-0.99]). CONCLUSION: In PD patients, social deprivation was not associated with death or the composite event of death or transfer to HD. Socially deprived individuals had a greater risk of transfer to HD and lower access to kidney transplantation in the competing risk analysis.

Sex-related differences in pre-dialysis trajectories and dialysis initiation: A French nationwide retrospective study.

BACKGROUND: In the last two decades, sex and gender differences have been documented in chronic kidney disease (CKD) management, including access to renal replacement therapy and its outcomes. The objectives of this study were to 1) compare the pre-dialysis healthcare utilization in men and women, and 2) examine the sex-specific factors associated with emergency dialysis start. METHODS: Adult patients with CKD who started dialysis in France in 2015 were extracted from the Renal Epidemiology and Information Network registry. Patients were matched to the French National Health Data System database to extract healthcare utilization data for the 2 years before dialysis start. Frequencies and monthly rates of consultations and hospitalizations were compared between men and women. Logistic regression analyses were performed separately in the two groups. RESULTS: Among the 8856 patients included, 3161 (35.7%) were women. Median age (71 years) and estimated glomerular filtration rate (8.1 and 7.7 ml/min for men and women) were similar between groups at dialysis start. Monthly consultations rates with a general practitioner and nephrology-related care were similar between women and men. Some sex-specific differences were found: higher frequencies of consultations with a psychiatrist in women and more frequent hospitalizations for circulatory system diseases in men. Emergency dialysis start rate was 30% in both groups. Emergency dialysis start was associated with acute nephropathy, compared with slowly progressive nephropathy, in women but not in men (OR = 1.48, p<0.01 vs 1.15, p = 0.18). CONCLUSIONS: This study found similar quantitative pre-dialysis healthcare utilization in men and women. To better understand sex/gender differences in CKD care trajectories, future research should focus on patients with CKD who are unknown to nephrology services, on patients receiving conservative care and on the sex/gender-specific mechanisms underlying care decision-making.

Lower access to kidney transplantation for women in France is not explained by comorbidities and social deprivation.

BACKGROUND: Access to kidney transplantation (KT) remains challenging for patients with end-stage kidney disease. This study assessed women's access to KT in France by considering comorbidities and neighborhood social deprivation. METHODS: All incident 18-85-year-old patients starting dialysis in France between January 1, 2017 and December 31, 2019 were included. Three outcomes were assessed: (i) access to the KT waiting list after dialysis start, (ii) KT access after waitlisting, and (iii) KT access after dialysis start. Cox and Fine and Gray models were used. Gender-EDI and gender-age interactions were tested and analyses were performed among strata if required. RESULTS: 29,395 patients were included (35% of women). After adjusting for social deprivation and comorbidities, women were less likely to be waitlisted at 1 (adjHR: 0.91 [0.87-0.96]) and 3 years (adjHR: 0.87 [0.84-0.91]) post-dialysis initiation. This disparity concerned mainly ≥60-year-old women (adjHR: 0.76 [0.71-0.82] at 1 year and 0.75 [0.71-0.81] at 3 years). Access to KT, after 2 years of waitlisting was similar between genders. Access to KT was similar between genders at 3 years after dialysis start, but decreased for women after 4 years (adjHR: 0.93 [0.88-0.99]) and longer follow-up (adjHR: 0.90 [0.85-0.96]). CONCLUSIONS: In France, women are less likely to be waitlisted and undergo kidney transplantation. This is driven by the ≥60-year-old group and is not explained by comorbidities or social deprivation level.

Effectiveness and safety of direct oral anticoagulants versus vitamin K antagonists in patients on chronic dialysis: a nationwide registry study.

BACKGROUND AND HYPOTHESIS: Clinical trials of direct oral anticoagulants (DOAC) are scarce and inconclusive in patients who are receiving dialysis, for whom DOAC are not labelled in Europe. In a French nationwide registry study of patients on chronic dialysis, we compared the effectiveness and safety of off-label DOAC use vs. approved vitamin K antagonist (VKA). METHODS: Data on patients on dialysis were extracted from the French Renal Epidemiology and Information Network (REIN) registry and merged with data from the French national healthcare system database (Système National des Données de Santé, SNDS). Patients on dialysis who had initiated treatment with an oral anticoagulant between January 1st, 2012, and December 31st, 2020, were eligible for inclusion. The primary safety outcome was the occurrence of major bleeding events and the primary effectiveness outcome was the occurrence of thrombotic events. Using propensity-score-weighted cause-specific Cox regression, we compared the safety and effectiveness outcomes for DOAC and VKA. RESULTS: 8,954 patients received an oral anticoagulant (483 DOAC and 8,471 VKA) for the first time after the initiation of dialysis. Over a median [interquartile range] follow-up period of 1.7 [0.8-3.2] years, 2,567 patients presented a first thromboembolic event and 1,254 patients had a bleeding event. After propensity score adjustment, the risk of a thromboembolic event was significantly lower in patients treated with a DOAC than in patients treated with a VKA (weighted hazard ratio (wHR) [95% confidence interval (CI)]: 0.66 [0.46; 0.94]. A non-significant trend toward a lower risk of major bleeding events was found in DOAC-treated patients, relative to VKA-treated patients (wHR [95%CI]: 0.68 [0.41; 1.12]). The results were consistent across subgroups and in sensitivity analyses. CONCLUSIONS: In a large group of dialysis patients initiating an oral anticoagulant, the off-label use of DOACs was associated with a significantly lower risk of thromboembolic events and a non-significantly lower risk of bleeding, relative to VKA use. This provides reassurance regarding the off-label use of DOACs in people on dialysis.

Epidemiology of tobacco use in dialysis patients in France and survey of nephrologists' involvement in counseling on tobacco discontinuation.

BACKGROUND: Tobacco smoking is an independent risk factor for chronic kidney disease (CKD) and increases morbidity and mortality in CKD patients. The primary objective of the study was to investigate the epidemiology of smoking in patients undergoing maintenance dialysis in France. A second objective was to assess the involvement of nephrologists in supporting patients for smoking cessation. METHODS: Data on the smoking history of prevalent patients on maintenance dialysis in France between 2010 and 2020 were obtained from the REIN database (Renal Epidemiology and Information Network), updated by all French nephrology and dialysis centers. As for the support to smoking discontinuation, a questionnaire on smoking cessation assistance was sent to all members of the French Society of Nephrology, Dialysis and Transplantation (SFNDT). RESULTS: The proportion of current smokers among patients on maintenance dialysis was 10.4% in 2010, 11.2% in 2015 and 11.6% in 2020. A total of 228 nephrologists among the 790 members of the SFNDT participated in the survey (28.9%). Most respondents were women (57.3%), worked at a public hospital (61.1%), were under 40 years of age (51.3%) and had no history of smoking (60.8%). The majority reported asking patients about their smoking status and offering brief advice. Among respondents, 72.8% offered help with smoking cessation, 46.3% referred their smoking patients to a tobacco specialist, 51.8% reported prescribing drugs to quit tobacco, and 81.6% requested further training in how to support patients for smoking cessation. CONCLUSION: Smoking cessation training for nephrologists and dedicated programs for patients in nephrology units could improve our practices and decrease the high prevalence of smoking in patients with ESKD.

Twenty years of the French Renal Epidemiology and Information Network.

Background: The French Renal Epidemiology and Information Network (REIN) is 20 years old. It is not just a national data registry, but rather an epidemiological and informational network serving patients with chronic kidney disease, nephrology teams and health services. Methods: The past 10-year trends of the incidence and prevalence of renal replacement therapy by dialysis or kidney transplantation and waitlist activity are presented. To detect potential significant changes in trends from 2012 and 2021, a Joinpoint regression model was used. Results: The overall incidence of treated end-stage kidney disease (ESKD) was 169 per million population (pmp) in 2021. It was stable despite an increase in the incidence of diabetes. We found a decreasing trend in the proportion of patients starting dialysis in an emergency but an increase in those starting haemodialysis (HD) with a temporary catheter. Peritoneal dialysis decreased by 1.7% each year, whereas home HD, although involving only 1% of dialysis patients, increased by 10% each year. For patients not treated at home, the median time to drive from the patient's home to the dialysis unit was 17 min. The proportion of patients on the transplantation waitlist at the start of dialysis increased from 7% to 12%. Among the 111 263 new ESKD patients from 2012 to 2021, 8% received a first transplant at 1 year and 20% at 5 years. Among kidney transplant recipients, the mean time on the waitlist increased from 13.8 to 22.6 months. Living donor transplants increased in frequency, representing 15% of kidney transplants. Conclusions: Data from the REIN registry allow for the evaluation of needs and provide a planning tool for French authorities. The progressive implementation of automatic data retrieval from dialysis informatics charts might alleviate the burden of data collection. Furthermore, the research activity the REIN engenders, resulting in renewed confidence by health authorities in the dynamism of French nephrology, allows for an optimistic outlook for the REIN.