The COVID-19 pandemic preferentially killed older people or people with prior comorbidities, of which KRT most increased the risk of death, followed by CKD.15 Indeed, COVID-19 decreased the prevalence of KRT in Spain for the first time.13,16 However, the REDYT report of a year-on-year increase in KRT prevalence of 1% from 2022 to 2023, to 67,548 people, exceeds prior expectations. The 2023 prevalence estimate provided by the prestigious Global Burden of Disease (GBD) study was 60,000 (95% confidence interval 59,200–60,800), i.e., 11% lower.14 The Inside CKD study projected around 61,000 on KRT by 2023 and expected to reach ≈68,000 by 2027.17 This means that the growth of the need for KRT exceeds expectations. This should come as no surprise, as the baby-boom generation, born in Spain between 1958 and 1975, is starting to reach the age of peak incidence of KRT. This increasing wave can only be stemmed by novel public policy approaches, such as a decided coordinated effort at the national level to diagnose CKD earlier by eliminating the barriers to the universal access to albuminuria testing.18

An interesting finding is that there was an inverse correlation between KRT incidence or prevalence and life expectancy at birth in different Autonomous Communities (Fig. 1).13,19 This was mainly driven by the inverse correlation found in people aged 65–74 years (r −0.57, p 0.022 for prevalence and r −0.725, p 0.0015 for incidence), as this is when KRT incidence and prevalence peak in most Autonomous Communities and when mortality starts to rise sharply in the general population. A statistically significant inverse correlation is already observed at 45–64 years for prevalence, likely because the annual incidence numbers are very low, especially in Autonomous Communities with small population, and more influenced by a few patients. At age 75+ years, a trend for an inverse correlation is still observed for prevalence data (r −0.50, p=0.0507). However, the result is influenced by the topic discussed in the next section: the very heterogeneous uptake of KRT among the very elderly by different Autonomous Communities.

Fig. 1.

Correlation between life expectancy at birth and KRT prevalence or incidence in adults. (A–C) KRT prevalence in all adults (A), those aged 45–64 years (B) or 65–74 years (C). (D and E) KRT incidence in all adults (D), those aged 45–64 years (E) or 65–74 years (F). For age-specific prevalence, no data was available for Asturias. Life expectancy at birth for Autonomous Communities for 2023 was obtained from INE (https://www.ine.es/jaxiT3/Tabla.htm?t=37664&L=1). Pearson r value and p value were calculated for the data shown.

Source for KRT prevalence and incidence: REDYT 2023.13.

Overall, the association of a lower KRT burden with better local life expectancy supports the hypothesis that the incidence and prevalence of KRT behave as key performance indicators of overall societal health. This hypothesis is further supported by its biological plausibility. KRT is just the tip of the iceberg of CKD. CKD sits at the crossroads of CKM health, the key driver of disease in developed countries. In fact, at the global level, CKM risk factors (blood pressure, glycemia, glomerular filtration rate, body mass index and LDL cholesterol) explain over 25% of global disability-adjusted life-years (DALYs), as opposed to 8.2% for particulate matter pollution and 5.5% for smoking.20 They also explain over 20 million annual global cardiovascular deaths, as opposed to 7–8 million each for lifestyle and environmental or occupational risks.21 The main adverse health effect of CKD is accelerated body aging,22 which translates into increased risks of disease or death from cardiovascular diseases, infection (e.g., COVID-19) and cancer, among others.23–25 These risks peak in patients on KRT.26 Indeed, despite its name, KRT only replaces partially one (glomerular filtration for dialysis) or multiple kidney functions (kidney transplantation). Patients on dialysis remain in the kidney failure stage from the point of view of glomerular filtration and dialysis does not replace the kidney gerosuppressor function consisting of the production of antiaging factors such as Klotho and betaine.27,28 While kidney grafts replace all kidney functions, they usually do it suboptimally, as there is only one organ, frequently from elderly donors, that has suffered ischemic, rejection and potentially even nephrotoxic insults.29 As a consequence, the remaining life expectancy of people on KRT is decades shorter than in the general population.30 It may reach up to over four decades shorter for young women on dialysis. In addition to these biological and epidemiological considerations, CKD and KRT also exert major psychosocial effects that further influence health outcomes.31,32

An ageing population is one of the key features of healthcare in Spain and Europe.33 Indeed, Spain is projected to have the longest life expectancy in the world by 204034 and Madrid already has the longest life expectancy among European regions.35 Even if the plummeting birth rate is compensated by immigration, the number of elderly people will skyrocket in the next few decades, driven by the baby-boom generation, born between 1958 and 1975. This generation is now aged 50–69 years and will bear the brunt of CKD as a cause of death by 2050. As GFR decreases with advancing age and the prevalence of risk factors and conditions that cause CKD increase with advancing age, it is expected that the incidence of kidney failure peaks in people aged 75+ years. Indeed, this is the case for European countries that do not limit access to KRT based on age.33,36 However, the incidence and prevalence of KRT in the very elderly is surprisingly heterogeneous among Autonomous Communities (Figs. 2 and 3). Two well defined groups of Autonomous Communities related to clinical practice for KRT in the elderly were apparent. In most regions, KRT incidence and prevalence increase with increasing age, peaking at 75+ years, as expected. In a few regions both KRT incidence and prevalence unexpectedly decrease in the oldest age group. Finally, in some regions the behavior of KRT prevalence and incidence differs. These were generally smaller regions, where prevalence should carry a larger weight as it represents the integration of multiple annual incidence and mortality episodes. Considering both the differential KRT prevalence and incidence between people aged 75+ and 65–74 years, the Valencia Community had the largest increase in KRT burden in those aged 75+ years over younger people, while the Basque Country had the largest decrease in burden from age 65–74 to age 75+ years (Fig. 3). Overall, there was a 40–50% difference between both Autonomous Communities in the differential KRT prevalence and incidence between both age groups. While the reasons underlying these differences are unknown, the phenomenon merits an in-depth characterization. Benchmarking studies should dissect the drivers of these differences and the differences in outcomes.

Fig. 2.

KRT prevalence and incidence according to age for different Autonomous Communities. (A) KRT prevalence. (B) KRT incidence. Black is used for the majority of Autonomous Communities in which KRT prevalence and incidence were higher at age 75+ than at age 65–74 years. Blue hues were used for Autonomous Communities in which the behaviour of KRT prevalence and KRT incidence was discrepant for the difference between 75+ and 65–74 years. Redish-orange hues were used for Autonomous Communities in which KRT prevalence and incidence were lower at age 75+ than at age 65–74 years. For age-specific prevalence, no data were available for Asturias.

Source: REDYT 2023.13.

Fig. 3.

KRT prevalence and incidence according to age for different Autonomous Communities. (A) KRT prevalence for people aged 65–74 or 75+ years. (B) KRT incidence for people aged 65–74 or 75+ years. Five groups of columns are shown. “75+>65–74” corresponds to Autonomous Communities shown in black in Fig. 2: both KRT prevalence and KRT incidence were higher in older people. “75+>or<65–74” corresponds to Autonomous Communities shown in blue hues in Fig. 2: either KRT prevalence or KRT incidence, but not both, were higher in younger people. “75+<65–74” corresponds to Autonomous Communities shown in reddish-orange hues in Fig. 2: both KRT prevalence and KRT incidence were higher in younger people. The same regions are represented in each group of columns in both graphs. Data shows median and interquartile range for all the Autonomous Communities in each group. Additionally, the Autonomous Communities in both extremes of the spectrum are shown. Mean of (Δincidence+Δprevalence) was used to select the extreme Autonomous Communities. For age-specific prevalence, no data was available for Asturias.

Source: REDYT 2023.13.

In current clinical practice there is an easy, low-cost, non-invasive and actionable method to diagnose and treat early CKD: albuminuria testing.8 Albuminuria testing is recommended by the 2021 ESC Guidelines on cardiovascular disease prevention in clinical practice, as means to diagnose CKD, since CKD conveys a high or very high risk of CVD that requires specific therapeutic interventions.37 In this regard, since KDIGO designed in 2012 the heatmap for risk stratification of people with CKD based on GFR and UACR values, it has become apparent that the diverse risks increase both vertically, as GFR decreases, and horizontally, as UACR increases.24 There is a biological plausibility of this observation, as albuminuria decreases the tubular cell production of the gerosuppressor Klotho38 and Klotho deficiency cause accelerated body aging and, by itself, reproduces the cardiovascular phenotype of CKD.39 A holistic ABCDE approach to CKM health has been emphasized by an ERA call to action.3,40 ABCDE stands for Albuminuria, Blood pressure, Cholesterol, Diabetes (i.e., glycemia) and Estimated GFR (Fig. 4). Thus, it summarizes the five parameters that healthcare systems should assess to identify key actionable (treatable) conditions whose treatment decreases cardiovascular events and CKD progression and prolongs a healthy life: chronic kidney disease (A, E), hypertension (B), hypercholesterolemia (C) and diabetes (D).

Fig. 4.

The European Renal Association (ERA) holistic approach to cardiovascular-kidney-metabolic health: as easy as ABCDE.

Despite decades of guideline recommendations to test for albuminuria in people with diabetes or hypertension and more recently with up to 21 risk factors for CKD,8 the uptake of albuminuria testing remains low, both in people with diabetes and, mainly for people without diabetes. In a sample Spanish hospital, albuminuria testing was one order of magnitude less common that the BCDE parameters.41 Assessing periodically 21 risk factors to determine who needs testing for albuminuria (cost as low as 0.3 euros) will pose an insurmountable challenge for primary care physicians. A new approach that bypasses the need for physicians to think about CKD and the act by ordering an albuminuria test should be implemented. This new approach would be a direct appeal to citizens, offering them free at the point-of-care screening for early CKD by assessing albuminuria, in the same manner that it is done now for colorectal cancer (estimated 2050 rank as a cause of death #6), breast cancer (2050 rank #17) and cervical cancer (2050 rank #>20).18 A small investment in CKD screening may go a long way to improving societal health. Albuminuria testing has roughly the same cost and logistics as stool testing for colorectal cancer, but a positive test triggers a second albuminuria testing which may diagnose CKD and indicate treatment with generic kidney protective drugs. Unlike the direct path from albuminuria screening to a CKD diagnosis, a positive cancer screening test may be associated with the uncertainty related to a potential cancer diagnosis and a second invasive and expensive testing. Universal screening may also address the equity issue in which women are less likely to get tested for albuminuria41 and also lose more years of remaining life expectancy while on KRT.30

The success of such population-based strategies, however, depends not only on healthcare system design but also on active citizen engagement. Promoting responsible citizenship, however, also requires that screening programs are accessible and adapted to what citizens are willing and able to assume. The target population for early CKD detection largely consists of individuals who perceive themselves as healthy and who are actively engaged in work, family and social life. For this population, screening strategies must be simple, minimally burdensome and compatible with an active lifestyle in order to achieve high participation rates.42,43 Importantly, this paradigm shift is now feasible thanks to the availability of reliable ambulatory technologies for the measurement of albuminuria and eGFR, which are simple to implement at scale and associated with an assumably low cost. The combination of technological feasibility, low economic burden and high potential health impact makes population-based CKD screening a realistic and timely public health intervention. Addressing psychosocial determinants of health and empowering citizens as active partners in prevention could therefore be central components of effective kidney health strategies.

REDYT, ALCER, EKPF, S.E.N. and RICORS240-renal call health authorities at the national and local level to implement the necessary steps to fulfill the 2025 WHO kidney health resolution. A starting point would be to implement the ERA holistic ABCDE approach to diagnose and monitor CKM health for adults aged 50+ years as well as those with additional risk factors. Given the dramatically suboptimal uptake of albuminuria testing as compared to the other ABCDE parameters, and the existent barriers, implementation of universal screening for albuminuria linked to universal screening of colorectal cancer may be a cost-effective implementation approach.

REDYT, ALCER, EKPF, S.E.N. and RICORS240-renal further call health authorities to monitor KRT incidence and prevalence as a key performance indicator of societal health. This indicator will allow benchmarking Autonomous Communities for best practices that by early diagnosis and treatment of high risk of CKD or CKD itself achieve a decreasing incidence of kidney failure and related KRT needs while maintaining universal access to KRT. Primary care is the key entry point for a successful fight against CKD and should be the focus of Autonomous Communities efforts, requiring the full engagement and collaboration of local Primary Care and Nephrological Societies, patient associations and healthcare systems. Monitoring should include clinical practice regarding albuminuria testing, adequate interpretation of test results leading to CKD diagnosis and uptake of guideline-recommended therapy that slows CKD progression and improves cardiovascular outcomes: renin-angiotensin system blockers, SGLT2 inhibitors statins, GLP1 receptor agonists and non-steroidal mineralocorticoid receptor antagonists.8,37,44–46

While Spain is an international leader in kidney transplantation and is taken as an example of how mortality from CKD can be reduced by achieving Spanish kidney transplantation rates,47 the best outcome for the population is never to develop CKD, followed by stabilizing CKD so as kidney failure does not develop and kidney transplantation is unnecessary.

AO research is funded by Comunidad de Madrid en Biomedicina P2022/BMD-7223, CIFRA_COR-CM. Instituto de Salud Carlos III (ISCIII) (PI22/00469, PI22/00050, PI21/00251, PI25/00145, ERA-PerMed-JTC2022 (SPAREKID AC22/00027), RICORS program to RICORS2040-renal (RD24/0004/0001) co-funded by European Union and SPACKDc PMP21/00109, FEDER funds; COST Action PERMEDIK CA21165 supported by COST (European Cooperation in Science and Technology); PREVENTCKD Consortium Project ID 101101220 Programme EU4H DG/Agency HADEA; KitNewCare Project ID 101137054, Call HORIZON-HLTH-2023-CARE-04, Programme HORIZON, DG/Agency HADEA; PICKED Project ID 101168626 HORIZON-MSCA-2023-DN-01-01 MSCA Doctoral Networks 2023. BQ research is funded by Instituto de Salud Carlos III (ISCIII) FIS/Fondos FEDER RICORS program to RICORS2040 (RD21/0005/0028) funded by European Union – NextGenerationEU, Mecanismo para la Recuperación y la Resiliencia (MRR) y PI25/00413. JCJ research is funded by 2C4Kidneys Project, Erasmus+Program 2025-1-EL01-KA210-ADU-000361754; Confudius Project, EP PerMed-JTC2025; Personalise-DKD Project EP PerMed-JTC2024; PreventCKD Project ID 101101220 Programme EU4H; KitNewCare Project ID 101137054, Call HORIZON-HLTH-2023-CARE-04, geneTIGA Project ID 101057438, Call HORIZON-HLTH-2021-TOOL-06.

AO has received consultancy or speaker fees or travel support from Astellas, AstraZeneca, Bioporto, Boehringer Ingelheim, Fresenius Medical Care, GSK, Bayer, Sanofi-Genzyme, Sobi, Menarini, Lilly, Chiesi, Otsuka, Novo-Nordisk, Sysmex and CSL-Vifor and Spafarma. B.Q. reports honorarium for conferences, consulting fees and advisory boards from Bayer, Novo Nordisk, Genzyme-Sanofi, AstraZeneca, Boehringer and CSL-Vifor. DG does not have conflict of interest. JCJ's institution received honoraria for his lectures and educational events from Astellas, AstraZeneca, Bayer, Vantive-Baxter, Ispen, Merck Sharp and Dohme, and Pfizer. The institution also received travel support from Astellas, Novartis, and Nova Biomedical.