BACKGROUND This paper compares the incidence and prevalence of kidney replacement therapy (KRT), kidney transplantation rates, and mortality on KRT between Europe and the United States (US), including sex comparisons. METHODS Data were derived for 2022 from the population-based European Renal Association (ERA) Registry and the United States Renal Data System (USRDS). RESULTS In 2022, the KRT incidence in the US (388.7 per million population (pmp)) was 2.7-fold higher than in Europe (146.2 pmp), with a greater difference for women (3.2-fold) than for men (2.4-fold). The proportion of women initiating KRT was lower in Europe (35%) than in the US (41%). Between 2013 and 2022, the KRT incidence in Europe was stable in women (+0.1% annually), but increased in men (+1.1%). In the US, the KRT incidence increased similarly in women (+0.2%) and men (+0.3%). On 31 December 2022, the KRT prevalence was 2-fold (women: 2.2-fold, men: 1.9-fold) higher in the US (2444.2 pmp) than in Europe (1218.6 pmp). The proportion of women was lower in Europe (38%) than in the US (41%). The kidney transplantation rate was 1.7-fold higher in the US (79.1 pmp) than in Europe (45.4 pmp), 1.9-fold for women and 1.7-fold for men, with women accounting for 37% of the recipients versus 39% in the US. The KRT mortality rate was 1.5 times higher in the US (145.0 per 1000 patient years (/1000py)) compared to Europe (100.5/1000py): 1.6-fold for women and 1.4-fold for men. In Europe, mortality was lower for women receiving KRT (93.7/1000py) than for men (104.6/1000py), whereas in the US the reverse was (women: 148.9/1000py, men: 142.2/1000py). CONCLUSION The US had a notably higher KRT incidence, prevalence, kidney transplantation rate and mortality compared to Europe. Differences between Europe and the US were larger for women than for men.

AIM Lung ultrasound (LUS) can be used for an assessment of volume overload in patients with end-stage kidney disease (ESKD) and those undergoing dialysis. The aim of this study was to analyse whether the initial use of LUS in evaluating volume status could benefit patients by optimizing haemodialysis treatment and improving their clinical status. METHODS The study included 50 haemodialysis patients in stage V of ESKD with the diagnosis of ischaemic heart failure with reduced (HFrEF) or midrange ejection fraction (HFmrEF). The assessment of volume status was verified solely by LUS (along with the analysis of B lines as measures of volume status). The specified laboratory parameters were performed initially, after three, and after six months. RESULTS The number of B-lines on LUS were decreased during the six-month follow-up compared to baseline, indicating a reduction in volume overload due to the LUS-guided protocol. Statistically significant differences were observed in the average creatinine (p=0.001) and parathormone (PTH) (p=0.003) levels over the six-month monitoring period. Significant differences were also noted in triglyceride (p=0.000) and potassium (p=0.02) levels. No significant differences were found in the values of other monitored parameters. CONCLUSION In haemodialysis patients diagnosed with heart failure, LUS can aid the achievement of a more efficient volume reduction by decreasing B-lines, which are indicative of congestion. Our study also demonstrated beneficial effects of LUS on potassium and parathormone levels.

The shortage of applications for fellowships in nephrology is a worldwide challenge. This is the first survey to explore in Europe the reasons physicians choose (and do not choose) a career in nephrology. An anonymous questionnaire was sent to the presidents of societies that are members of the European Renal Association (ERA), who invited trainees and nephrologists to respond. Statistical analysis was performed using SPSS v.26. (SPSS Inc., Chicago, IL, USA). Continuous variables were compared by Student's t-test or by one-way ANOVA. Responders included 516 (49%) females and 542 (51%) males. They comprised 278 (26%) trainees, and 780 (74%) nephrologists. The majority (64%) believe that students have an unfavourable perception of nephrology. For trainees, nephrology is not considered an attractive option due to ‘chronically ill patients’ (35%), ‘lack of contact during undergraduate training’ (37%), ‘nephrology is too challenging’ (38%), ‘poor remuneration’ (22%), ‘negative role models’ (15%), and ‘long working hours’ (14%). The factors with the greatest impact on choosing a career include a positive role model (46%), practical experience during medical school and early postgraduate training (42%). Trainees emphasize that work–life balance is very important for the younger generation. A strong mentorship along with early engagement is associated with a higher likelihood of pursuing a career in nephrology. It is crucial to create a strategy that will provide a positive experience, renew the interest in nephrology careers and ensure enough nephrologists to treat the growing number of patients with kidney disease.

ABSTRACT Background Inherited kidney diseases (IKDs) and congenital anomalies of the kidney and urinary tract (CAKUT) are causes of kidney failure requiring kidney replacement therapy (KRT) that major renal registries usually amalgamate into the primary renal disease(PRD) category ‘miscellaneous’ or in the glomerulonephritis or pyelonephritis categories. This makes IKDs invisible (except for polycystic kidney disease) and may negatively influence the use of genetic testing, which may identify a cause for IKDs and some CAKUT. Methods We re-examined the aetiology of KRT by composing a separate IKD and CAKUT PRD group using data from the European Renal Association (ERA) Registry. Results In 2019, IKD-CAKUT was the fourth most common cause of kidney failure among incident KRT patients, accounting for 8.9% of cases [IKD 7.4% (including 5.0% autosomal dominant polycystic kidney disease), CAKUT 1.5%], behind diabetes (23.0%), hypertension (14.4%) and glomerulonephritis (10.6%). IKD-CAKUT was the most common cause of kidney failure among patients <20 years of age (41.0% of cases), but their incidence rate was highest among those ages 45–74 years (22.5 per million age-related population). Among prevalent KRT patients, IKD-CAKUT (18.5%) and glomerulonephritis (18.7%) were the two most common causes of kidney failure overall, while IKD-CAKUT was the most common cause in women (21.6%) and in patients <45 years of age (29.1%). Conclusion IKD and CAKUT are common causes of kidney failure among KRT patients. Distinct categorization of IKD and CAKUT better characterizes the epidemiology of the causes of chronic kidney disease (CKD) and highlights the importance of genetic testing in the diagnostic workup of CKD.

ABSTRACT Background In 2020, the coronavirus disease 2019 (COVID-19) pandemic caused disruptions in kidney replacement therapy (KRT) services worldwide. The aim of this study was to assess the effect of the COVID-19 pandemic in 2020 on the incidence of KRT, kidney transplantation activity, mortality and prevalence of KRT across Europe. Methods Patients receiving KRT were included from 17 countries providing data to the European Renal Association Registry. The epidemiology of KRT in 2020 was compared with average data from the period 2017–2019. Changes occurring during the first and second waves of the pandemic were also explored. Results The incidence of KRT was 6.2% lower in 2020 compared with 2017–2019, with the lowest point (−22.7%) during the first wave in April. The decrease varied across countries, was smaller in males (−5.2%) than in females (−8.2%) and was moderate for peritoneal dialysis (−3.7%) and haemodialysis (−5.4%) but substantial for pre-emptive kidney transplantation (−23.6%). The kidney transplantation rate decreased by 22.5%, reaching a nadir of −80.1% during the first wave, and was greatest for living donor kidney transplants (−30.5%). While in most countries the kidney transplantation rate decreased, in the Nordic/Baltic countries and Greece there was no clear decrease. In dialysis patients, mortality increased by 11.4% and was highest in those 65–74 years of age (16.1%), in those with diabetes as the primary renal disease (15.1%) and in those on haemodialysis (12.4%). In transplant recipients, the mortality was 25.8% higher, but there were no subgroups that stood out. In contrast to the rising prevalence of KRT observed over the past decades across Europe, the prevalence at the end of 2020 (N = 317 787) resembled that of 2019 (N = 317 077). Conclusion The COVID-19 pandemic has had a substantial impact on the incidence of KRT, kidney transplant activity, mortality of KRT and prevalence of KRT in Europe with variations across countries.

ABSTRACT Background This paper compares the most recent data on the incidence and prevalence of kidney replacement therapy (KRT), kidney transplantation rates, and mortality on KRT from Europe to those from the United States (US), including comparisons of treatment modalities (haemodialysis (HD), peritoneal dialysis (PD), and kidney transplantation (KTx)). Methods Data were derived from the annual reports of the European Renal Association (ERA) Registry and the United States Renal Data System (USRDS). The European data include information from national and regional renal registries providing the ERA Registry with individual patient data. Additional analyses were performed to present results for all participating European countries together. Results In 2021, the KRT incidence in the US (409.7 per million population (pmp)) was almost 3-fold higher than in Europe (144.4 pmp). Despite the substantial difference in KRT incidence, approximately the same proportion of patients initiated HD (Europe: 82%, US: 84%), PD (14%; 13%, respectively), or underwent pre-emptive KTx (4%; 3%, respectively). The KRT prevalence in the US (2436.1 pmp) was 2-fold higher than in Europe (1187.8 pmp). Within Europe, approximately half of all prevalent patients were living with a functioning graft (47%), while in the US, this was one third (32%). The number of kidney transplantations performed was almost twice as high in the US (77.0 pmp) compared to Europe (41.6 pmp). The mortality of patients receiving KRT was 1.6-fold higher in the US (157.3 per 1000 patient years) compared to Europe (98.7 per 1000 patient years). Conclusions The US had a much higher KRT incidence, prevalence, and mortality compared to Europe, and despite a higher kidney transplantation rate, a lower proportion of prevalent patients with a functioning graft.

ABSTRACT Background Primary glomerular disease (PGD) is a major cause of end-stage kidney disease (ESKD) leading to kidney replacement therapy (KRT). We aimed to describe incidence (trends) in individuals starting KRT for ESKD due to PGD and to examine their survival and causes of death. Methods We used data from the European Renal Association (ERA) Registry on 69 854 patients who started KRT for ESKD due to PGD between 2000 and 2019. ERA primary renal disease codes were used to define six PGD subgroups. We examined age and sex standardized incidence, trend of the incidence and survival. Results The standardized incidence of KRT for ESKD due to PGD was 16.6 per million population (pmp), ranging from 8.6 pmp in Serbia to 20.0 pmp in France. Immunoglobulin A nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS) had the highest incidences, of 4.6 pmp and 2.6 pmp, respectively. Histologically non-examined PGDs represented over 50% of cases in Serbia, Bosnia and Herzegovina, and Romania and were also common in Greece, Estonia, Belgium and Sweden. The incidence declined from 18.6 pmp in 2000 to 14.5 pmp in 2013, after which it stabilized. All PGD subgroups had 5-year survival probabilities above 50%, with crescentic glomerulonephritis having the highest risk of death [adjusted hazard ratio 1.8 (95% confidence interval 1.6–1.9)] compared with IgAN. Cardiovascular disease was the most common cause of death (33.9%). Conclusion The incidence of KRT for ESKD due to PGD showed large differences between countries and was highest and increasing for IgAN and FSGS. Lack of kidney biopsy facilities in some countries may have affected accurate assignment of the cause of ESKD. The recognition of the incidence and outcomes of KRT among different PGD subgroups may contribute to a more individualized patient care approach.

ABSTRACT Background The European Renal Association (ERA) Registry collects data on kidney replacement therapy (KRT) in patients with end-stage kidney disease (ESKD). This paper is a summary of the ERA Registry Annual Report 2021, including a comparison across treatment modalities. Methods Data was collected from 54 national and regional registries from 36 countries, of which 35 registries from 18 countries contributed individual patient data and 19 registries from 19 countries contributed aggregated data. Using this data, incidence and prevalence of KRT, kidney transplantation rates, survival probabilities and expected remaining lifetimes were calculated. Result In 2021, 533.2 million people in the general population were covered by the ERA Registry. The incidence of KRT was 145 per million population (pmp). In incident patients, 55% were 65 years or older, 64% were male, and the most common primary renal disease (PRD) was diabetes (22%). The prevalence of KRT was 1040 pmp. In prevalent patients, 47% were 65 years or older, 62% were male, and the most common PRDs were diabetes and glomerulonephritis/sclerosis (both 16%). On 31 December 2021, 56% of patients received haemodialysis, 5% received peritoneal dialysis, and 39% were living with a functioning graft. The kidney transplantation rate in 2021 was 37 pmp, a majority coming from deceased donors (66%). For patients initiating KRT between 2012–2016, 5-year survival probability was 52%. Compared to the general population, life expectancy was 65% and 68% shorter for males and females receiving dialysis, and 40% and 43% shorter for males and females living with a functioning graft.