Mapping end-stage renal disease (ESRD): spatial variations on small area level in northern France, and association with deprivation

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.

Incidence of End Stage Kidney Disease and context of dialysis initiation

On the occasion of the 20th anniversary of the REIN (French Renal Epidemiology and Information Network), a summary work on the contributions of the national French ESKD register was carried out. On the issue of ESKD incidence, the following key messages were retained. Thanks to several studies conducted using data from the REIN registry, the spatial variations of incidence of stage 5 chronic kidney disease in the replacement stage could be explained, in part, by the health condition of the general population as well as by the socio-economic context and differences in practices. Just like what is observed in other countries, the incidence is stabilising, or even decreasing, especially among people who do not have diabetes. Thanks to the registry having provided an indicator on the initiation of the dialysis, a decrease in the rate of initiation of emergency dialysis (i.e., initiated less than 24 hours after a nephrology evaluation considering a vital risk for the patient) has been observed, resulting from an effort to understand and better anticipate the starting of the replacement.

Final Stage of Chronic Kidney Disease with Conservative Kidney Management or Renal Replacement Therapy: A Primary-Care Population Study

BACKGROUND

Studies focus on the incidence and risk factors (RFs) associated with reaching the final stage of chronic kidney disease (CKD-G5) and receiving kidney replacement therapy (KRT). Analysis of those related to reaching CKD-G5 while receiving conservative kidney management (CKM) has been neglected.

METHODS

Retrospective cohort study analysing electronic health records of individuals aged ≥ 50 with eGFR < 60 mL/min/m². Cumulative incidence rates of CKD-G5, with and without KRT, were calculated. Multinomial regression models determined odds ratios (ORs) for CKD-G5 progression with KRT, CKM, or death.

RESULTS

Among 332,164 patients, the cumulative incidence of CKD-G5 was 2.79 cases per 100 person-years. The rates were 1.92 for CKD-G5 with KRT and 0.87 for CKD-G5 with CKM. Low eGFR and albuminuria were the primary RFs. Male gender and uncontrolled blood pressure had a greater impact on KRT (OR = 2.63 CI, 1.63) than on CKD-G5 with CKM (OR = 1.45 CI, 1.31). Increasing age and rurality reduced the probability of KRT but increased the probability of CKD-G5 with CKM. Higher incomes decreased the likelihood of developing CKD-G5 with and without KRT (OR = 0.49 CI).

CONCLUSION

One-third of CKD-G5 cases receive CKM. Those are typically older, female, rural residents with lower incomes and with lesser proteinuria or cardiovascular RF. The likelihood of receiving KRT is influenced by location and socioeconomic disparities.

Use of spatial panel-data models to investigate factors related to incidence of end-stage renal disease: a nationwide longitudinal study in Taiwan

BACKGROUND

The assumptions of conventional spatial models cannot estimate the responses across space and over time. Here we propose new spatial panel data models to investigate the association between the risk factors and incidence of end-stage renal disease (ESRD).

METHODS

A longitudinal (panel data) study was conducted using data from the National Health Insurance Database in Taiwan. We developed an algorithm to identify the patient's residence and estimate the ESRD rate in each township. Corresponding covariates, including patient comorbidities, history of medication use, and socio-environmental factors, were collected. Local Indicators of Spatial Association were used to describe local spatial clustering around an individual location. Moreover, a spatial panel data model was proposed to investigate the association between ESRD incidence and risk factors.

RESULTS

In total, 73,995 patients with ESRD were included in this study. The western region had a higher proportion of high incidence rates than the eastern region. The proportion of high incidence rates in the eastern areas increased over the years. We found that most "social environmental factors," except average income and air pollution (PM 2.5 and PM10), had a significant influence on the incidence rate of ESRD when considering spatial dependences of response and explanatory variables. Receiving non-steroidal anti-inflammatory drugs and aminoglycosides within 90 days prior to ESRD had a significant positive effect on the ESRD incidence rate.

CONCLUSION

Future comprehensive studies on townships located in higher-risk clusters of ESRD will help in designing healthcare policies for suitable action.

Fine-scale geographic variations of rates of renal replacement therapy in northeastern France: Association with the socioeconomic context and accessibility to care

Background

The strong geographic variations in the incidence rates of renal replacement therapy (RRT) for end-stage renal disease are not solely related to variations in the population's needs, such as the prevalence of diabetes or the deprivation level. Inequitable geographic access to health services has been involved in different countries but never in France, a country with a generous supply of health services and where the effect of the variability of medical practices was highlighted in an analysis conducted at the geographic scale of districts. Our ecological study, performed at the finer scale of townships in a French area of 8,370,616 inhabitants, investigated the association between RRT incidence rates, socioeconomic environment and geographic accessibility to healthcare while adjusting for morbidity level and medical practice patterns.

Methods

Using data from the Renal Epidemiology and Information Network registry, we estimated age-adjusted RRT incidence rates during 2010–2014 for the 282 townships of the area. A hierarchical Bayesian Poisson model was used to examine the association between incidence rates and 18 contextual variables describing population health status, socioeconomic level and health services characteristics. Relative risks (RRs) and 95% credible intervals (95% CrIs) for each variable were estimated for a 1-SD increase in incidence rate.

Results

During 2010–2014, 6,835 new patients ≥18 years old (4231 men, 2604 women) living in the study area started RRT; the RRT incidence rates by townships ranged from 21 to 499 per million inhabitants. In multivariate analysis, rates were related to the prevalence of diabetes [RR (95% CrI): 1.05 (1.04–1.11)], the median estimated glomerular filtration rate at dialysis initiation [1.14 (1.08–1.20)], and the proportion of incident patients ≥ 85 years old [1.08 (1.03–1.14)]. After adjusting for these factors, rates in townships increased with increasing French deprivation index [1.05 (1.01–1.08)] and decreased with increasing mean travel time to reach the closest nephrologist [0.92 (0.89–0.95]).

Conclusion

These data confirm the influence of deprivation level, the prevalence of diabetes and medical practices on RRT incidence rates across a large French area. For the first time, an association was found with the distance to nephrology services. These data suggest possible inequitable geographic access to RRT within the French health system.

Role of Area-Level Access to Primary Care on the Geographic Variation of Cardiometabolic Risk Factor Distribution: A Multilevel Analysis of the Adult Residents in the Illawarra-Shoalhaven Region of NSW, Australia

BACKGROUND

Access to primary care is important for the identification, control and management of cardiometabolic risk factors (CMRFs). This study investigated whether differences in geographic access to primary care explained area-level variation in CMRFs.

METHODS

Multilevel logistic regression models were used to derive the association between area-level access to primary care and seven discrete CMRFs after adjusting for individual and area-level co-variates. Two-step floating catchment area method was used to calculate the geographic access to primary care for the small areas within the study region.

RESULTS

Geographic access to primary care was inversely associated with low high density lipoprotein (OR 0.94, CI 0.91-0.96) and obesity (OR 0.91, CI 0.88-0.93), after adjusting for age, sex and area-level disadvantage. The intra-cluster correlation coefficient (ICCs) of all the fully adjusted models ranged between 0.4-1.8%, indicating low general contextual effects of the areas on CMRF distribution. The area-level variation in CMRFs explained by primary care access was ≤10.5%.

CONCLUSION

The findings of the study support proportionate universal interventions for the prevention and control of CMRFs, rather than any area specific interventions based on their primary care access, as the contextual influence of areas on all the analysed CMRFs were found to be minimal. The findings also call for future research that includes other aspects of primary care access, such as road-network access, financial affordability and individual-level acceptance of the services in order to gain an overall picture of the area-level contributing role of primary care on CMRFs in the study region.

Intraregional differences in renal function in the Northern Netherlands: The Lifelines Cohort Study

Background

Although the interregional disparity in chronic kidney disease (CKD) prevalence has been reported globally, little is known about differences in CKD prevalence within a region. We aimed to study the intraregional distribution of renal function in the Northern Netherlands and identify determinants of geographical differences in renal function.

Methods

We included 143,735 participants from the Lifelines population-based cohort in the Northern Netherlands. Spatial analysis was performed to identify regional clusters of lower eGFR (cold spots) and higher eGFR (hot spots) at the postal code level, without and with adjustment for clinical risk factors. Multivariate logistic regression was used to identify the contribution of neighborhood-level health-related behaviors, socioeconomic status, and environmental factors (air pollution parameters, urbanity) to regional clustering of lower eGFR.

Results

Significant spatial clustering of renal function was found for eGFR as well as for early stage renal function impairment (eGFR<90 ml/min/1.73 m²), (p<0.001). Spatial clustering persisted after adjustment of eGFR for clinical risk factors. In adjusted cold spots, the aggregate eGFR was lower (mean ± SD: 96.5±4.8 vs. 98.5±4.0 ml/min/1.73 m², p = 0.001), and the prevalence of early stage renal function impairment (35.8±10.9 vs. 28.7±9.8%, p<0.001) and CKD stages 3–5 was higher (median (interquartile range): 1.2(0.1–2.4) vs 0(0–1.4)%, p<0.001) than in hot spots. In multivariable logistic regression, exposure to NO₂ (Odd ratio [OR], 1.45; 95% confidence interval [95% CI], 1.19 to 1.75, p<0.001) was associated with cold spots (lower renal function), whereas proportion of fat intake in the diet (OR, 0.68; 95%CI, 0.48–0.97, P = 0.031) and income (OR, 0.91; 95%CI, 0.86–0.96, p<0.001) for median level income) were inversely related.

Conclusions

Significant intraregional clustering of renal function, early renal function impairment and CKD were observed in the Northern Netherlands even after adjustment for renal function-related clinical risk factors. Environmental (air pollution), neighborhood-level socioeconomic factors and diet are determinants of intraregional renal function distribution. Spatial analysis might be a useful adjunct to guide public health strategies for the prevention of CKD.

Population-based incidence of lymphomas in the French Nord-Pas-de-Calais region between 2001 and 2005: Annual estimations and spatial analysis

BACKGROUND

Non-Hodgkin's lymphomas (NHL) are the seventh most commonly diagnosed cancer in France. Nord-Pas-de-Calais is ranked as the region with the highest incidence of cancers and deaths by cancer in France. With its rich industrial past and its contrasted population densities between urban and rural territories, Nord-Pas-de-Calais represents a geographic area of interest to study the overall incidence of NHL and examine spatial variation of NHL incidence between the 170 cantons of the region.

METHODS

LYMPHONOR was a population-based multicentre retrospective study of patients residing in the Nord-Pas-de-Calais region and diagnosed with NHL between January 2001 and December 2005. Spatial distribution of NHL incidence in Nord-Pas-de-Calais was explored using two complementary approaches: adjusted smoothed standardised incidence ratio (SIR) and spatial scan statistics (detection of atypical clusters).

RESULTS

Between 2001 and 2005, 2132 new cases of NHL were diagnosed in the Nord-Pas-de-Calais region. In 2005, age-standardised NHL incidence rates were 10.2 and 7.0 cases per 100,000 person-years in male and female residents, respectively. No significant spatial disparities in NHL incidence were found within the Nord-Pas-de-Calais region. The age-adjusted smoothed SIR varied from 0.82 to 1.25 between cantons. Consistently, spatial scan statistics did not detect any significant atypical cluster of high NHL incidence.

CONCLUSION

Comparison with national data collected during the same period does not show an overincidence of NHL in the Nord-Pas-de-Calais region. In addition, no evidence for spatial heterogeneity and clustering of NHL incidence was found within this region. Future epidemiological research using large-scale registries is needed to better appraise spatial variation of NHL incidence in France and to investigate possible reasons for significant clusters.

[What do registries compared to clinical trials tell us?]

The objective of this review is to illustrate the interests of registries in terms of clinical research, using practical examples from the French REIN registry. In addition to their interest in terms of observation and decision-making for public health, registries may also be used to compare structures, and to evaluate causality in clinical research. Indeed, even though randomized controlled trials are the gold standard to assess causality, they may be difficult to perform, with an applicability in daily life that remains to be demonstrated since patients are highly selected patients with a very close follow-up. In contrast, observational studies from registries have other advantages, and notably high number of patients, low cost, relatively rapid research, focus on specific sub-groups. In the future, data mining with an implementation of a huge number of data for patients (hospitalization data, genetics, ambulatory care, etc.) will dramatically improve the databases. We may even imagine running RCTs directly in registries, with lower costs and patients closer to reality. However, many challenges remain to be solved, and notably the ethical issues of confidentiality and protection of patients in these "mega-databases". Cet article fait partie du numéro supplément Innovations en Néphrologie réalisé avec le soutien institutionnel de Vifor Fresenius Medical Care Renal Pharma.

Geographic and area-level socioeconomic variation in cardiometabolic risk factor distribution: a systematic review of the literature

INTRODUCTION

A growing number of publications report variation in the distribution of cardiometabolic risk factors (CMRFs) at different geographic scales. A review of these variations may help inform policy and health service organisation.

AIM

To review studies reporting variation in the geographic distribution of CMRFs and its association with various proxy measures of area-level socioeconomic disadvantage (ASED) among the adult ( ≥ 18 years) population across the world.

METHODS

A systematic search for published articles was conducted in four databases (MEDLINE (Ovid), PubMed, Scopus and Web of Science) considering the interdisciplinary nature of the review question. Population-based cross-sectional and cohort studies on geographic variations of one or more biological proxies of CMRFs with/without an analysed contextual association with ASED were included. Two independent reviewers screened the studies and PRISMA guidelines were followed in the study selection and reporting.

RESULT

A total of 265 studies were retrieved and screened, resulting in 24 eligible studies. The review revealed reports of variation in the distribution of CMRFs, at varying geographic scales, in multiple countries. In addition, consistent associations between ASED and higher prevalence of CMRFs were demonstrated. The reports were mainly from industrialised nations and small area geographic units were frequently used.

CONCLUSION

Geographic variation in cardiometabolic risk exists across multiple spatial scales and is positively associated with ASED. This association is independent of individual-level factors and provides an imperative for area-based approaches to informing policy and health service organisation. The study protocol is registered in International prospective register of systematic reviews (Register No: CRD42018115294) PROSPERO 2018.

Malaria intensity in Colombia by regions and populations

Determining the distribution of disease prevalence among heterogeneous populations at the national scale is fundamental for epidemiology and public health. Here, we use a combination of methods (spatial scan statistic, topological data analysis and epidemic profile) to study measurable differences in malaria intensity by regions and populations of Colombia. This study explores three main questions: What are the regions of Colombia where malaria is epidemic? What are the regions and populations in Colombia where malaria is endemic? What associations exist between epidemic outbreaks between regions in Colombia? Plasmodium falciparum is most prevalent in the Pacific Coast, some regions of the Amazon Basin, and some regions of the Magdalena Basin. Plasmodium vivax is the most prevalent parasite in Colombia, particularly in the Northern Amazon Basin, the Caribbean, and municipalities of Sucre, Antioquia and Cordoba. We find an acute peak of malarial infection at 25 years of age. Indigenous and Afrocolombian populations experience endemic malaria (with household transmission). We find that Plasmodium vivax decreased in the most important hotspots, often with moderate urbanization rate, and was re-introduced to locations with moderate but sustained deforestation. Infection by Plasmodium falciparum, on the other hand, steadily increased in incidence in locations where it was introduced in the 2009-2010 generalized epidemic. Our findings suggest that Colombia is entering an unstable transmission state, where rapid decreases in one location of the country are interconnected with rapid increases in other parts of the country.

Impact of social deprivation on length of stay for common infectious diseases in two French university-affiliated general pediatric departments

BACKGROUND

Adult deprived patients consume more healthcare resources than others, particularly in terms of increased length of stay (LOS) and costs. Very few pediatric studies have focused on LOS, although the effect of deprivation could be greater in children due to the vulnerability of this population. Our objective was to compare LOS between deprived and nondeprived children hospitalized for acute infectious diseases in two university-affiliated pediatric departments located in a low-income area of northern Paris.

METHODS

We performed a prospective observational multicenter study in two university-affiliated hospitals, Hôpital Robert-Debré and Hôpital Jean-Verdier. All the patients under 15 years of age admitted to the general pediatric department for pneumonia, bronchiolitis, gastroenteritis, or pyelonephritis between 20 October 2016 and 20 March 2017 were included. Deprivation was assessed with an individual questionnaire and score (EPICES). Endpoints included length of stay, costs, and readmission rates at 15 days in each quintile of deprivation. Multivariate regression assessed the association between deprivation and each endpoint.

RESULTS

A total of 556 patients were included in the study and 540 were analyzed. Sixty percent were boys and the mean age was 9 months±18. Bronchiolitis was the most frequent diagnosis (67.8%). Fifty-six percent of patients were considered to be deprived based on the EPICES questionnaire. Mean LOS was 4.6±3.5 days and we found no significant difference in LOS between the different deprivation quintiles (P=0.83). Multivariate regression did not show an association between LOS and deprivation.

CONCLUSION

There was no difference between deprived and nondeprived patients in terms of LOS. Deprivation may therefore impact hospitals in other ways such as admission rates. The impact of deprivation during hospitalization for chronic diseases should also be investigated.

Management of rare diseases of the Head, Neck and Teeth: results of a French population-based prospective 8-year study

BACKGROUND

In the last ten years, national rare disease networks have been established in France, including national centres of expertise and regional ones, with storage of patient data in a bioinformatics tool. The aim was to contribute to the development and evaluation of health strategies to improve the management of patients with rare diseases. The objective of this study has been to provide the first national-level data concerning rare diseases of the head, neck and teeth and to assess the balance between demand and supply of care in France.

METHODS

Centres of expertise for rare diseases record a minimum data set on their clinical cases, using a list of rare Head, Neck and Teeth diseases established in 2006. The present analysis focuses on 2008 to 2015 data based on the Orphanet nomenclature. Each rare disease RD "case" was defined by status "affected" and by the degree of diagnostic certainty, encoded as: confirmed, probable or non-classifiable. Analysed parameters, presented with their 95% confidence intervals using a Poisson model, were the following: time and age at diagnosis, proportions of crude and standardized RD prevalence by age, gender and geographical site. The criteria studied were the proportions of patients in Paris Region and the "included cases geography", in which these proportions were projected onto the other French Regions, adjusting for local populations.

RESULTS

In Paris Region, estimated prevalence of these diseases was 5.58 per 10,000 inhabitants (95% CI 4.3-7.1). At December 31st 2015, 11,342 patients were referenced in total in France, of whom 7294 were in Paris Region. More than 580 individual clinical entities (ORPHA code) were identified with their respective frequencies. Most abnormalities were diagnosed antenatally. Nearly 80% of patients recorded come to Paris hospitals to obtain either diagnosis, care or follow up. We observed that the rarer the disease, the more patients were referred to Paris hospitals.

CONCLUSIONS

A health network covering a range of aspects of the rare diseases problematic from diagnostics to research has been developed in France. Despite this, there is still a noticeable imbalance between health care supply and demand in this area.

Geographic Variation and US County Characteristics Associated With Rapid Kidney Function Decline

Introduction

Geographic variation in the prevalence of chronic kidney disease and incidence of end-stage renal disease has been previously reported. However, the geographic epidemiology of rapid estimated glomerular filtration rate (eGFR) decline has not been examined.

Methods

We built a longitudinal cohort of 2,107,570 US veterans to characterize the spatial epidemiology of and examine the associations between US county characteristics and rapid eGFR decline.

Results

There were 169,029 (8.02%) with rapid eGFR decline (defined as eGFR slope < –5 ml/min per 1.73 m²/year). The prevalence of rapid eGFR decline adjusted for age, race, gender, diabetes, and hypertension varied by county from 4.10%–6.72% in the lowest prevalence quintile to 8.41%–22.04% in the highest prevalence quintile (P for heterogeneity < 0.001). Examination of adjusted prevalence showed substantial geographic variation in those with and without diabetes and those with and without hypertension (P for heterogeneity < 0.001). Cohort participants had higher odds of rapid eGFR decline when living in counties with unfavorable characteristics in domains including health outcomes (odds ratio [OR] = 1.15; confidence interval [CI] = 1.09–1.22), health behaviors (OR = 1.08; CI = 1.03–1.13), clinical care (OR = 1.11; CI = 1.06–1.16), socioeconomic conditions (OR = 1.15; CI = 1.09–1.22), and physical environment (OR = 1.15; CI = 1.01–1.20); living in counties with high percentage of minorities and immigrants was associated with rapid eGFR decline (OR = 1.25; CI = 1.20–1.31). Spatial analyses suggest the presence of cluster of counties with high prevalence of rapid eGFR decline.

Discussion

Our findings show substantial geographic variation in rapid eGFR decline among US veterans; the variation persists in analyses stratified by diabetes and hypertension status; results show associations between US county characteristics in domains capturing health, socioeconomic, environmental, and diversity conditions, and rapid eGFR decline.