Diagnostic Yield of Population-Based Screening for Chronic Kidney Disease in Low-Income, Middle-Income, and High-Income Countries

Individual and neighborhood-level social and deprivation factors impact kidney health in the GLOMMS-CORE study

Prospective cohort studies of kidney equity are limited by a focus on advanced rather than early disease and selective recruitment. Whole population studies frequently rely on area-level measures of deprivation as opposed to individual measures of social disadvantage. Here, we linked kidney health and individual census records in the North of Scotland (Grampian area), 2011-2021 (GLOMMS-CORE) and identified incident kidney presentations at thresholds of estimated glomerular filtration rate (eGFR) under 60 (mild/early), under 45 (moderate), under 30 ml/min/1.73m2 (advanced), and acute kidney disease (AKD). Household and neighborhood socioeconomic measures, living circumstances, and long-term mortality were compared. Case-mix adjusted multivariable logistic regression (living circumstances), and Cox models (mortality) incorporating an interaction between the household and the neighborhood were used. Among census respondents, there were 48546, 29081, 16116, 28097 incident presentations of each respective eGFR cohort and AKD. Classifications of socioeconomic position by household and neighborhood were related but complex, and frequently did not match. Compared to households of professionals, people with early kidney disease in unskilled or unemployed households had increased mortality (adjusted hazard ratios: 95% confidence intervals) of (1.26: 1.19-1.32) and (1.77: 1.60-1.96), respectively with adjustment for neighborhood indices making little difference. Those within either a deprived household or deprived neighborhood experienced greater mortality, but those within both had the poorest outcomes. Unskilled and unemployed households frequently reported being limited by illness, adverse mental health, living alone, basic accommodation, lack of car ownership, language difficulties, and visual and hearing impairments. Thus, impacts of deprivation on kidney health are spread throughout society-complex, serious, and not confined to those living in deprived neighborhoods.

Prospective Study on Kidney Dysfunction Markers and Risk for Mortality among South Asians

Introduction

Associations between markers of impaired kidney function and adverse outcomes among South Asians is understudied and could differ from existing data derived mostly from North American or European cohorts.

Methods

We conducted a prospective analysis of 9797 participants from the ongoing cardiometabolic risk reduction study in South Asia, India. We examined the associations between baseline spot urine albumin-to-creatinine (UACR) ratio and creatinine-based estimated glomerular filtration rate (eGFR) estimating equations with all-cause mortality using Cox proportional hazards regression, adjusting for baseline age, sex, diabetes, systolic blood pressure, tobacco, history of cardiovascular disease, and cholesterol. Additionally, we calculated population attributable fraction (PAF) for both markers.

Results

Over a median 7-year follow-up, with 66,909 person-years, 791 deaths occurred. At baseline, the weighted prevalence of UACR ≥ 30 mg/g and eGFRCKD-EPI 2009 <60 ml/min per 1.73 m2 was 6.6% and 1.6%, respectively. The risk for mortality was increased with higher UACR (10-30 hazard ratio [HR]: 1.6 [1.2-2.1]), 30-300 HR: 2.4 [1.8-3.1]), and ≥300 (HR: 6.0 [3.8-9.4] relative to UACR <10 mg/g). Risk for mortality was also higher with lower eGFRCKD-EPI 2009 (44-30; HR: 4.5 [2.5-8.3] and <30 HR: 7.0 [3.7-13.0], relative to 90-104 ml/min per 1.73 m2). PAF for mortality because of UACR ≥30 mg/g and eGFRCKD-EPI 2009 <45 ml/min per 1.73 m2 were 24.4% and 13.4%, respectively.

Conclusion

Single-time point assessment of UACR ≥30 mg/g or eGFRCKD-EPI 2009 <45 ml/min per 1.73 m2 portends higher mortality risk among urban South Asians. Because albuminuria is common and associated with accelerated decline in GFR, screening and targeted efforts to reduce albuminuria are warranted.

The Future of Kidney Care in Low- and Middle-Income Countries: Challenges, Triumphs, and Opportunities

CKD affects about 850 million people worldwide and is projected to be the fifth leading cause of death by 2040. Individuals from low- and middle-income countries (LMICs) bear the bulk of CKD. They face challenges including lack of awareness among the general population, as well as health care providers, unique risk factors such as genetic predispositions, infectious diseases, and environmental toxins, limited availability and affordability of diagnostic tests and medications, and limited access to KRTs. The inadequate health system infrastructure, human resources, and financing mechanisms to support comprehensive and integrated kidney care worsen the situation. Overcoming these challenges needs concerted efforts toward early detection, intervention, and multidisciplinary follow-up, policy, collaboration, advocacy, and financing. To achieve this, there is need for individual governments to include kidney health among the key health priorities and build capacity toward resilient health care systems. Integrating kidney care using the roadmaps of well-established management systems for other chronic diseases, such as HIV, has the potential to expedite the widespread adoption of kidney health. The aim of this article is to provide an overview of the current state and future prospects of kidney care in LMICs, highlighting the main challenges, ongoing efforts, and opportunities for improvement. We present case studies of exemplary efforts from three continents of the world with the highest densities of LMICs and propose potential strategies for a sustainable solution.

Prediction of incident chronic kidney disease in community-based electronic health records: a systematic review and meta-analysis

Background

Chronic kidney disease (CKD) is a major global health problem and its early identification would allow timely intervention to reduce complications. We performed a systematic review and meta-analysis of multivariable prediction models derived and/or validated in community-based electronic health records (EHRs) for the prediction of incident CKD in the community.

Methods

Ovid Medline and Ovid Embase were searched for records from 1947 to 31 January 2024. Measures of discrimination were extracted and pooled by Bayesian meta-analysis, with heterogeneity assessed through a 95% prediction interval (PI). Risk of bias was assessed using Prediction model Risk Of Bias ASsessment Tool (PROBAST) and certainty in effect estimates by Grading of Recommendations, Assessment, Development and Evaluation (GRADE).

Results

Seven studies met inclusion criteria, describing 12 prediction models, with two eligible for meta-analysis including 2 173 202 patients. The Chronic Kidney Disease Prognosis Consortium (CKD-PC) (summary c-statistic 0.847; 95% CI 0.827-0.867; 95% PI 0.780-0.905) and SCreening for Occult REnal Disease (SCORED) (summary c-statistic 0.811; 95% CI 0.691-0.926; 95% PI 0.514-0.992) models had good model discrimination performance. Risk of bias was high in 64% of models, and driven by the analysis domain. No model met eligibility for meta-analysis if studies at high risk of bias were excluded, and certainty of effect estimates was 'low'. No clinical utility analyses or clinical impact studies were found for any of the models.

Conclusions

Models derived and/or externally validated for prediction of incident CKD in community-based EHRs demonstrate good prediction performance, but assessment of clinical usefulness is limited by high risk of bias, low certainty of evidence and a lack of impact studies.

Participation rate and yield of two home-based screening methods to detect increased albuminuria in the general population in the Netherlands (THOMAS): a prospective, randomised, open-label implementation study

BACKGROUND

Chronic kidney disease (CKD) has a rising global prevalence and is expected to become the fifth leading cause of death by 2030. Increased albuminuria defines the early stages of CKD and is among the strongest risk factors for progressive CKD and cardiovascular disease. The value of population screening for albuminuria to detect CKD in an early phase has yet to be studied. We aimed to evaluate the effectiveness of two home-based albuminuria population screening methods.

METHODS

Towards Home-based Albuminuria Screening (THOMAS) was a prospective, randomised, open-label implementation study that invited Dutch adults aged 45-80 years for albuminuria screening. Individuals were randomly assigned (1:1) to screening by applying either a urine collection device (UCD) that was sent by post to a central laboratory for measurement of the albumin-to-creatinine ratio (ACR) by immunoturbidimetry or to screening via a smartphone application that measures the ACR with a dipstick method at home. Randomisation was done with a four-block method via a web-based system and was stratified by age, sex, and socioeconomic status. If two or more individuals per household were invited to participate, these individuals were randomly assigned to the same group. In case of confirmed increased albuminuria at home, participants were invited for an elaborate screening in a regional hospital (Amphia Hospital, Breda, Netherlands) for CKD and cardiovascular risk factors. When abnormalities were found, participants were referred to their general practitioner for treatment. The primary outcomes were the participation rate and yield of the home-based screening and elaborate screening. Participation rate was assessed in the intention-to-screen population (ie, all participants who were invited for the home-based screening or elaborate screening). Yield was assessed in the per-protocol population (ie, all individuals who participated in the home-based screening or elaborate screening). An exploratory analysis assessed the sensitivity and specificity of both home-based screening methods. To this end, an additional quantitative ACR test was performed among people participating in the elaborate screening, and a substudy was performed among participants with a first negative home-based screening test, who were invited for an additional test. The study is registered with ClinicalTrials.gov, NCT04295889.

FINDINGS

15 074 participants were enrolled between Nov 14, 2019, and March 19, 2021. 7552 (50·1%) were randomly assigned to home-based albuminuria screening by the UCD method and 7522 (49·9%) were assigned to albuminuria screening by the smartphone application method. The participation rate of the home-based screening was 4484 (59·4% [95% CI 58·3-60·5]) of the 7552 invited individuals for the UCD method and 3336 (44·3% [43·2-45·5]) of 7522 invited individuals for the smartphone application method (p<0·0001). Increased ACR was confirmed by home-based testing in 150 (3·3% [95% CI 2·9-3·9]) of 4484 individuals for the UCD method and 171 (5·1% [4·4-5·9]) of 3336 indivduals for the smartphone application method. 124 (82·7% [95% CI 75·8-87·9]) of 150 individuals assigned to the UCD method and 142 (83·0% [76·7-87·9]) of 171 participants assigned to the smartphone application method attended the elaborate screening. Sensitivity to detect increased ACR was 96·6% (95% CI 91·5-99·1) for the UCD method and 98·1% (89·9-99·9) for the smartphone application method, and specificity was 97·3% (94·7-98·8) for the UCD method and 67·9% (62·0-73·3) for the smartphone application method, indicating that the test characteristics of only the UCD method were sufficient for screening. Albuminuria, hypertension, hypercholesterolaemia, and decreased kidney function were newly diagnosed in 77 (62·1%), 44 (35·5%), 30 (24·2%), and 27 (21·8%) of 124 participants for the UCD method, respectively. Of the 124 participants assigned to the UCD method who completed elaborate screening, 111 (89·5%) were referred to their general practitioner for treatment because of newly diagnosed CKD or cardiovascular disease risk factors or known risk factors outside the target range.

INTERPRETATION

Home-based screening of the general population for increased ACR using a UCD had a high participation rate and correctly identified individuals with increased albuminuria and yet unknown or known but outside target range CKD and cardiovascular risk factors. By contrast, the smartphone application method had a lower at-home participation rate than the UCD method and the test specificity was too low to accurately assess individuals for risk factors during the elaborate screening. The UCD screening strategy could allow for an early start of treatment to prevent progressive kidney function loss and cardiovascular disease in patients with CKD.

FUNDING

Dutch Kidney Foundation, Top Sector Life Sciences & Health of the Dutch Ministry of Economic Affairs.

Early Identification of Chronic Kidney Disease – A Scoping Review of the Global Populations

Introduction

Decisions on whether to screen for chronic kidney disease (CKD) or not remain contentious in nephrology. This study provides a global overview of early CKD identification efforts.

Methods

Guidelines for scoping reviews were followed and studies were identified by searching MEDLINE, EMBASE, Cochrane Library, CINAHL, ISI Web of Science, and PsycINFO. Data extracted from included studies focused on the following 4 themes: study population, measurement methods, interventions used, and available policies.

Results

We identified 290 CKD screening and detection programs from 83 countries. Overall sample size was 3.72 million (North East Asia: 1.19 million), detection of CKD was the aim in 97.6%, 63.1% used population-based screening methods, and only 12.4% were in rural populations. Reported CKD prevalence (stages 3–5) was higher in targeted- (14.8%) than population-based studies (8.0%). Number of persons needed to screen (NNS) to identify 1 case was also lower in targeted studies (7 vs. 13). Single measurements (80%) and the combination of estimation of glomerular filtration rate with a urine test (albuminuria/proteinuria) (71.4%) were frequently used to detect CKD. Only 2.8% of studies included an intervention such as pharmacotherapy in identified cases. Policies on early identification were available in 30.1% of countries included.

Conclusion

Methods for early CKD identification vary worldwide, often leading to wide variations in the reported prevalence. Efforts to standardize measurement methods for early detection focusing on high-risk populations and ensuring appropriate interventions are available to those identified with CKD will improve the value of programs and improve patient outcomes.