Effect of ethnicity and socioeconomic deprivation on uptake of renal supportive care and dialysis decision making in older adults

Background Renal supportive care has become an increasingly relevant treatment option as the renal patient population ages. Despite the prevalence of kidney disease amongst ethnic minority and socioeconomically deprived patients, evidence focused on supportive care and dialysis decision making in these groups is limited. Methods This retrospective study selected older patients referred to a low clearance or supportive care service between 1 January 2015 and 31 December 2019. A descriptive analysis of clinical and socioeconomic characteristics according to treatment choice was produced and multivariate logistic regression models used to identify predictive factors for choosing supportive care. Surrogate markers for the success of decision making processes were evaluated, including time taken to reach a supportive care decision and risk of death without making a treatment decision or within 3 months of starting kidney replacement therapy (KRT). Finally, the association between ethnicity and socioeconomic status and hospital admission rates were compared between treatment groups. Results Amongst 1768 patients, 515 chose supportive care and 309 chose KRT. Predictive factors for choosing supportive care included age, frailty and a diagnosis of cognitive impairment. However, there was no association with ethnicity or deprivation. Similarly, these factors were not associated with time taken to make a supportive care decision or the mortality outcome. Amongst those on KRT, more socially advantaged patients had decreased rates of hospital admissions compared with those less adavantaged (IRR 0.96, 95% CI 0.92–0.99)

Let's take the heat out of the CKDu debate: more evidence is needed.

There is considerable controversy about the causes of the epidemics of chronic kidney disease of undetermined causes (CKDu), affecting agricultural communities in Central America, South Asia and possibly other parts of the world. In this Editorial, we argue that currently none of the suggested hypotheses have enough evidence, either for or against them, to draw firm conclusions

Chronic kidney disease of undetermined aetiology: tens of thousands of premature deaths, yet too much remains unknown.

Tens of thousands of working-age adults have been dying from unexplained end-stage renal disease (ESRD) in Central America and South Asia. As the cause of this chronic kidney disease (CKD) remains unknown, the condition(s) (a unified aetiopathology has not been confirmed) has been termed ‘CKD of undetermined aetiology’ (CKDu). ‘CKD of non-traditional aetiology’, ‘chronic interstitial nephritis in agricultural communities’, ‘Mesoamerican nephropathy’, ‘Sri Lankan agricultural nephropathy’ and ‘Uddanam nephropathy’ are also used, but here we use the term CKDu

What do epidemiological studies tell us about chronic kidney disease of undetermined cause in Meso-America? A systematic review and meta-analysis.

BACKGROUND: The aim of this systematic review is to examine the epidemiological knowledge and gaps in understanding of the potential causes of chronic kidney disease of undetermined cause (CKDu) in Meso-America. METHODS: A systematic literature search of epidemiological studies of CKDu was conducted in PubMed, Embase and Web of Science from January 2000 to January 2017. Study quality was assessed by adapting the tool from Higgins et al. for observational studies. Where applicable, the summary prevalence odds ratio (POR) and 95% confidence interval (CI) were calculated using a random effects model. RESULTS: Twenty-five epidemiological studies were included in the analysis of risk factors for CKDu. The quality assessment of each occupational and community study was medium. The PORs for CKDu were males versus females 2.42 (95% CI 1.76-3.08), family history of CKD (versus none) 1.84 (95% CI 1.37-2.30), high water intake (versus low) 1.61 (95% CI 1.01-2.21) and low altitude (versus highland) 2.09 (95% CI 1.00-3.17). There were no significant associations between CKDu and pesticide exposure (versus no) 1.17 (95% CI 0.87-1.46), alcohol consumption (versus no) 1.34 (95% CI 0.84-1.84), non-steroidal anti-inflammatory drugs (versus no) 0.99 (95% CI 0.60-1.39) and heat stress (versus no) 1.52 (95% CI -0.91 - 3.95). CONCLUSION: Our meta-analysis showed positive associations for males (versus females) and family history of CKD, water intake, lowland altitude and CKDu. There were no significant associations with pesticide exposure, non-steroidal anti-inflammatory drugs intake, heat stress and alcohol consumption

Urinary biomarkers of tubular injury in chronic kidney disease.

It has been suggested that urinary biomarkers of tubular injury might help predict progression to end-stage renal disease. In this issue, Hsu et al. report that in those with established chronic kidney disease, this information does not add to what we know by quantifying creatinine and albuminuria. Here we discuss the evidence for urinary tubular injury markers in predicting renal outcomes in chronic kidney disease and the areas where measurement of these molecules might be useful in the future

Chronic kidney disease and cause-specific hospitalisation: a matched cohort study using primary and secondary care patient data.

BACKGROUND: Although chronic kidney disease (CKD) is associated with various outcomes, the burden of each condition for hospital admission is unknown. AIM: To quantify the association between CKD and cause-specific hospitalisation. DESIGN AND SETTING: A matched cohort study in primary care using Clinical Practice Research Datalink linked to Hospital Episode Statistics in England. METHOD: Patients with CKD (estimated glomerular filtration rate <60 mL/min/1.73 m2 for ≥3 months) and a comparison group of patients without known CKD (matched for age, sex, GP, and calendar time) were identified, 2004-2014. Outcomes were hospitalisations with 10 common conditions as the primary admission diagnosis: heart failure; urinary tract infection; pneumonia; acute kidney injury (AKI); myocardial infarction; cerebral infarction; gastrointestinal bleeding; hip fracture; venous thromboembolism; and intracranial bleeding. A difference in the incidence rate of first hospitalisation for each condition was estimated between matched patients with and without CKD. Multivariable Cox regression was used to estimate a relative risk for each outcome. RESULTS: In a cohort of 242 349 pairs of patients, with and without CKD, the rate difference was largest for heart failure at 6.6/1000 person-years (9.7/1000 versus 3.1/1000 person-years in patients with and without CKD, respectively), followed by urinary tract infection at 5.2, pneumonia at 4.4, and AKI at 4.1/1000 person-years. The relative risk was highest for AKI with a fully adjusted hazard ratio of 4.90, 95% confidence interval (CI) = 4.47 to 5.38, followed by heart failure with 1.66, 95% CI = 1.59 to 1.75. CONCLUSION: Hospitalisations for heart failure, infection, and AKI showed strong associations with CKD in absolute and(or) relative terms, suggesting targets for improved preventive care

International Collaboration for the Epidemiology of eGFR in Low and Middle Income Populations - Rationale and core protocol for the Disadvantaged Populations eGFR Epidemiology Study (DEGREE).

BACKGROUND: There is an increasing recognition of epidemics of primarily tubular-interstitial chronic kidney disease (CKD) clustering in agricultural communities in low- and middle-income countries (LMICs). Although it is currently unclear whether there is a unified underlying aetiology, these conditions have been collectively termed CKD of undetermined cause (CKDu). CKDu is estimated to have led to the premature deaths of tens to hundreds of thousands of young men and women over the last 2 decades. Thus, there is an urgent need to understand the aetiology and pathophysiology of these condition (s). International comparisons have provided the first steps in understanding many chronic diseases, but such comparisons rely on the availability of standardised tools to estimate disease prevalence. This is a particular problem with CKD, since the disease is asymptomatic until the late stages, and the biases inherent in the methods used to estimate the glomerular filtration rate (GFR) in population studies are highly variable across populations. METHOD: We therefore propose a simple standardised protocol to estimate the distribution of GFR in LMIC populations - The Disadvantaged Populations eGFR Epidemiology (DEGREE) Study. This involves the quantification of renal function in a representative adult population-based sample and a requirement for standardisation of serum creatinine measurements, along with storage of samples for future measurements of cystatin C and ascertainment of estimates of body composition, in order to obtain valid comparisons of estimated GFR (eGFR) within and between populations. DISCUSSION: The methodology we present is potentially applicable anywhere, but our particular focus is on disadvantaged populations in LMICs, since these appear to be most susceptible to CKDu. Although the protocol could also be used in specific groups (e.g. occupational groups, thought to be at excess risk of CKDu) the primary aim of the DEGREE project is characterise the population distribution of eGFR in multiple regions so that international comparisons can be performed. It is only with a standardised approach that it will be possible to estimate the scale of, and variation in, impaired kidney function between affected areas. These data should then provide insights into important social, demographic and environmental risk factors for this increasingly recognised disease

The National CKD Audit: a primary care condition that deserves more attention.

Chronic kidney disease (CKD) is a common condition, with an estimated prevalence in the UK of around 5–7%, and a GP recorded prevalence in the England Quality and Outcomes Framework (QOF) in 2017 of 4.1%,3 which is higher than the prevalence of coronary heart disease. The majority of people with CKD are detected and managed in primary care rather than by kidney specialists. Early identification in primary care, particularly among populations with risk factors such as diabetes and hypertension, enables appropriate management of blood pressure, cardiovascular risk and lifestyle factors. There is evidence that progression of CKD can be delayed by such interventions, and that implementation of these interventions can be improved by use of quality improvement tools in primary care. However CKD as a long-term condition has not had an easy ride. Since its definition in 2002 there have been concerns about overdiagnosis, described as ‘when people without symptoms are diagnosed with a disease that ultimately will not cause them symptoms or early death’, and anxieties about the disclosure of early-stage CKD to patients, along with the work of reassurance and increased monitoring that this might entail. This debate within general practice has left some practitioners uncertain about the importance of naming, coding and managing CKD in primary care

Rationale, description and baseline findings of a community-based prospective cohort study of kidney function amongst the young rural population of Northwest Nicaragua.

BACKGROUND: An epidemic of Mesoamerican Nephropathy (MeN) is killing thousands of agricultural workers along the Pacific coast of Central America, but the natural history and aetiology of the disease remain poorly understood. We have recently commenced a community-based longitudinal study to investigate Chronic Kidney Disease (CKD) in Nicaragua. Although logistically challenging, study designs of this type have the potential to provide important insights that other study designs cannot. In this paper we discuss the rationale for conducting this study and summarize the findings of the baseline visit. METHODS: The baseline visit of the community-based cohort study was conducted in 9 communities in the North Western Nicaragua in October and November 2014. All of the young men, and a random sample of young women (aged 18-30) without a pre-existing diagnosis of CKD were invited to participate. Glomerular filtration rate (eGFR) was estimated with CKD-EPI equation, along with clinical measurements, questionnaires, biological and environmental samples to evaluate participants' exposures to proposed risk factors for MeN. RESULTS: We identified 520 young adults (286 males and 234 females) in the 9 different communities. Of these, 16 males with self-reported CKD and 5 females with diagnoses of either diabetes or hypertension were excluded from the study population. All remaining 270 men and 90 women, selected at random, were then invited to participate in the study; 350 (97%) agreed to participate. At baseline, 29 (11%) men and 1 (1%) woman had an eGFR <90 mL/min/1.73 m2. CONCLUSION: Conducting a community based study of this type requires active the involvement of communities and commitment from local leaders. Furthermore, a research team with strong links to the area and broad understanding of the context of the problem being studied is essential. The key findings will arise from follow-up, but it is striking that 5% of males under aged 30 had to be excluded because of pre-existing kidney disease, and that despite doing so 11% of males had an eGFR <90 mL/min/1.73 m2 at baseline

Prevalence and risk factors for chronic kidney disease of unknown cause in Malawi: a cross-sectional analysis in a rural and urban population.

BACKGROUND: An epidemic of chronic kidney disease of unknown cause (CKDu) is occurring in rural communities in tropical regions of low-and middle-income countries in South America and India. Little information is available from Southern African countries which have similar climatic and occupational characteristics to CKDu-endemic countries. We investigated whether CKDu is prevalent in Malawi and identified its potential risk factors in this setting. METHODS: We conducted a cross-sectional study from January-August 2018 collecting bio samples and anthropometric data in two Malawian populations. The sample comprised adults > 18 years (n = 821) without diabetes, hypertension, and proteinuria. Estimates of glomerular filtration rate (eGFR) were calculated using the CKD-EPI equation. Linear and logistic regression models were applied with potential risk factors, to estimate risk of reduced eGFR. RESULTS: The mean eGFR was 117.1 ± 16.0 ml/min per 1.73m2 and the mean participant age was 33.5 ± 12.7 years. The prevalence of eGFR< 60 was 0.2% (95% confidence interval (95% CI) 0.1, 0.9); the prevalence of eGFR< 90 was 5% (95% CI =3.2, 6.3). We observed a higher prevalence in the rural population (5% (3.6, 7.8)), versus urban (3% (1.4, 6.7)). Age and BMI were associated with reduced eGFR< 90 [Odds ratio (OR) (95%CI) =3.59 (2.58, 5.21) per ten-year increment]; [OR (95%CI) =2.01 (1.27, 3.43) per 5 kg/m2 increment] respectively. No increased risk of eGFR < 90 was observed for rural participants [OR (95%CI) =1.75 (0.50, 6.30)]. CONCLUSIONS: Reduced kidney function consistent with the definition of CKDu is not common in the areas of Malawi sampled, compared to that observed in other tropical or sub-tropical countries in Central America and South Asia. Reduced eGFR< 90 was related to age, BMI, and was more common in rural areas. These findings are important as they contradict some current hypothesis that CKDu is endemic across tropical and sub-tropical countries. This study has enabled standardized comparisons of impaired kidney function between and within tropical/subtropical regions of the world and will help form the basis for further etiological research, surveillance strategies, and the implementation and evaluation of interventions