The Role of Patient-Reported Experience and Outcome Measures in Kidney Health Equity-Oriented Quality Improvement

Risk, prevalence, management, and outcomes in chronic kidney disease (CKD) are influenced by social and broader determinants of health. Consequently, there are wide-ranging kidney health inequities. As patients are key stakeholders, their perspectives on the care they receive and on health status are central in guiding health system improvement, particularly to reduce the impact of disadvantage. Patient-reported experience measures (PREMs) and patient-reported outcome measures (PROMs) are important self-report tools in quality improvement, acting to guide initatives aimed at enhancing access to timely and relevant support. However, the extent to which PREMs and PROMs address the reduction of kidney health inequities is unclear. The aim of this review is to summarize how PREMs and PROMs are designed and implemented, highlighting key dimensions that are integral to health equity-oriented quality improvement in kidney care. There are several problems yet to be overcome so that such tools do not unintentionally reproduce kidney health gaps. Inclusive generation of the scope of tools, transparent reporting on attributes of patients who engage, and embedding PREMs and PROMs within a framework of value-based quality improvement is fundamental to their impact as part of equitable health system transformation. Semin Nephrol 36:x-xx © 20XX Elsevier Inc. All rights reserved.

Community Point of Care Testing in Diagnosing and Managing Chronic Kidney Disease

Chronic kidney disease (CKD) poses a significant global health challenge with increasing prevalence and associated morbidity. Point-of-care testing (POCT) provides an opportunity to improve CKD management and outcomes through early detection and targeted interventions, particularly in underserved communities. This review evaluates the roles of POCT in CKD, focusing on utility (through screening programs, monitoring of kidney function, and assessing participants on renally excreted medications), accuracy, and acceptability. Screening programs employing POCT have demonstrated promising outcomes, with improved rates of CKD diagnosis in groups with disparate health outcomes, offering a vital avenue for early intervention in high-risk populations. These have been conducted in rural and urban community or pharmacy settings, highlighting convenience and accessibility as important facilitators for participants. In addition, POCT holds significant promise in the monitoring of CKD, particularly in groups requiring frequent testing, such as kidney transplant recipients and patients on renin-angiotensin-aldosterone inhibitors. The consideration of the variable analytical performance of different devices remains crucial in assessing the utility of a POCT intervention for CKD. While the convenience and improved accessibility of home self-testing versus healthcare professional management is important, it must be balanced with acceptable levels of accuracy and precision to maintain patient and clinical confidence. Despite challenges including variability in accuracy and the user-friendliness of devices, patient feedback has generally remained positive, with studies reporting increased patient satisfaction and engagement. However, challenges regarding wider uptake are limited by healthcare professional confidence (in test reliability), the potential for increased workload, and early prohibitive costs. In conclusion, POCT represents a growing and valuable tool in enhancing CKD care, particularly in resource-limited settings, but careful consideration of device selection and implementation strategies is essential to achieve desired outcomes.

Performance and pitfalls of the tools for measuring glomerular filtration rate to guide chronic kidney disease diagnosis and assessment

Accurate diagnosis, classification and risk stratification for chronic kidney disease (CKD) allow for early recognition and delivering optimal care. Creatinine-based glomerular filtration rate (GFR), urinary albumin: creatinine ratio (UACR) and the kidney failure risk equation (KFRE) are important tools to achieve this, but understanding their limitations is important for optimal implementation.When accurate GFR is required (eg, chemotherapy dosing), GFR is measured using an exogenous filtration marker. In routine clinical practice, in contrast, estimated GFR (eGFR) from serum creatinine (SCr), calculated using the enzymatic method±UACR, is recommended. Limitations of SCr include non-GFR determinants such as muscle mass, diet and tubular handling. An alternative or additional endogenous filtration marker is cystatin C, which can be used alongside SCr for confirmatory testing of CKD. However, its role in the UK is more limited due to concerns regarding false positive results.The recommended creatinine-based eGFR equation in the UK is the CKD Epidemiology Collaboration 2009 equation. This was recently updated to a race-neutral 2021 version and demonstrated reduced bias in people of Black ethnicity, but has not been validated in the UK. Limitations are extremes of age, inaccuracy at greater GFRs and reduced generalisability to under-represented ethnicity groups.The KFRE (based on age, sex, SCr and UACR) has recently been developed to help determine 2-year and 5-year risk of progression to end-stage kidney disease. It has been validated in over 30 countries and provides meaningful quantitative information to patients. However, supporting evidence for their performance in ethnic minority groups and kidney diseases such as glomerulonephritis remains modest.In conclusion, early identification, risk stratification of kidney disease and timely intervention are important to impact kidney disease progression. However, clinician awareness of the limitations and variability of creatinine, cystatin C and the eGFR equations, is key to appropriate interpretation of results.

Estimated glomerular filtration rate in Korean patients exposed to long-term lithium maintenance therapy

Background

Lithium-induced nephrotoxicity has long been debated. However, it has been rarely explored in Asian populations. The aim of the present study was to assess the effect of lithium maintenance therapy on estimated glomerular filtration rate (eGFR) in Korean patients diagnosed with a psychiatric illness.

Methods

This was a single-centered, retrospective study that included patients treated with lithium or comparator drug (valproate) in Samsung Seoul Medical Center between November 1994 and July 2020. Patients diagnosed with ICD codes F20-33 who had  ≥ 6 months of exposure to lithium or valproate were included. Patients had to have  ≥ 1 baseline and  ≥ 2 post-baseline eGFR data with post-baseline data having an interval of at least 30 days. Chronic kidney disease (CKD) was defined as CKD stage 3 (eGFR  < 60 mL/min/1.73²). To be considered as CKD, the threshold had to be met at two consecutive post-baseline measurements. Those treated with both lithium and valproate, diagnosed with CKD stages 3–5, diagnosed with a renal disease, or received kidney transplantation were excluded.

Results

A total of 766 patients were included (242 treated with lithium and 524 with valproate). Two (0.8%) in the lithium group and 8 (1.5%) in the valproate group developed CKD stage 3. None developed CKD stages 4–5. Median yearly eGFR change was − 1.3 mL/min/1.73² (IQR: − 6.8, 1.7) for the lithium group and − 1.1 mL/min/1.73² (IQR: − 4.5, 1.5) for the valproate group, showing no significant difference between the two groups (p  = 0.389). The rate of decline was more rapid for those with CKD in both groups. eGFR values of lithium and valproate groups did not show significant differences during a follow-up duration of 15 years or more. A significant negative correlation between baseline eGFR and yearly eGFR change was identified in a linear regression analysis.

Conclusions

In Korean patients, treatment with lithium did not increase the risk of developing CKD compared to treatment with valproate. Prevalence of CKD was lower than those previously reported in western populations. Low baseline eGFR showed significant correlation with changes in renal function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40345-022-00249-5.

Estimated glomerular filtration rate equations in people of self-reported black ethnicity in the United Kingdom: Inappropriate adjustment for ethnicity may lead to reduced access to care

Assessment in African populations suggest adjustment for ethnicity in estimated glomerular filtration rate (eGFR) equations derived from African Americans lead to overestimation of GFR and failure to determine severity in chronic kidney disease (CKD). However, studies in African Europeans are limited. We aimed to assess accuracy of eGFR equations, with and without ethnicity adjustment compared with measured GFR in people of Black ethnicity in the United Kingdom. Performance of MDRD, CKD-EPI (with and without ethnicity adjustment), Full Age Spectrum (FAS), revised Lund Malmö (LM Revised), and European Kidney Function Consortium (EKFC) eGFR equations were assessed compared to 51Cr-EDTA GFR studies extracted from hospital databases. Participants with albumin <30g/l, liver disease, <18 years, of non-Black or non-White self-reported ethnicity were excluded. Agreement was assessed by bias, precision and 30%-accuracy and was stratified for ethnicity and GFR. 1888 51Cr-EDTA studies were included (Mean age-53.7yrs; 43.6% female; 14.1% Black ethnicity). Compared to White participants, eGFR-MDRD and eGFR-CKD-EPI equations in Black participants significantly overestimated GFR (bias 20.3 and 19.7 ml/min/1.73m2 respectively, p<0.001). Disregarding the ethnicity adjustment significantly improved GFR estimates for Black participants (bias 6.7 and 2.4ml/min/1.73m2 for eGFR-MDRD and eGFR-CKD-EPI respectively, p<0.001). The LM Revised equation had the smallest bias for both White and Black participants (5.8ml and -1.1ml/min/1.73m2 respectively). 30%-accuracy was superior for GFR≥60ml/min/1.73m2 compared to <60ml/min/1.73m2 using eGFR-CKD-EPI equation for both White and Black participants (p<0.001). Multivariate regression methodology with adjustment for age, sex and log(serum creatinine) in the cohort yielded an ethnicity coefficient of 1.018 (95% CI: 1.009-1.027). Overestimation of measured GFR with eGFR equations using ethnicity adjustment factors may lead to reduced CKD diagnosis and under-recognition of severity in people of Black ethnicity. Our findings suggest that ethnicity adjustment for GFR estimation in non-African Americans may not be appropriate for use in people of Black ethnicity in the UK.

Sex Differences in Renal Function: Participation of Gonadal Hormones and Prolactin

Kidney pathophysiology is influenced by gender. Evidence suggests that kidney damage is more severe in males than in females and that sexual hormones contribute to this. Elevated prolactin concentration is common in renal impairment patients and is associated with an unfavorable prognosis. However, PRL is involved in the osmoregulatory process and promotes endothelial proliferation, dilatation, and permeability in blood vessels. Several proteinases cleavage its structure, forming vasoinhibins. These fragments have antagonistic PRL effects on endothelium and might be associated with renal endothelial dysfunction, but its role in the kidneys has not been enough investigated. Therefore, the purpose of this review is to describe the influence of sexual dimorphism and gonadal hormones on kidney damage, emphasizing the role of the hormone prolactin and its cleavage products, the vasoinhibins.

The Global Kidney Health Atlas: Burden and Opportunities to Improve Kidney Health Worldwide

CKD is a growing public health problem. The Global Kidney Health Atlas (GKHA) is an important initiative of the International Society of Nephrology. The GKHA aims to improve the understanding of inter- and intranational variability across the globe, focusing on capacity for kidney care delivery. The GKHA survey was launched in 2017 and then again in 2019, using the same core data, supplemented by information about dialysis access and conservative care. Based on a WHO framework of the 6 building blocks essential for health care, the GKHA assesses capacity in 6 domains: information systems, services delivery, workforce, financing, access to essential medicines, and leadership/governance. In addition, the GKHA assesses the capacity for research in all regions of the world, across all domains (basic, translational, clinical, and health system research). The results of the GKHA have informed policy and been used to enhance advocacy strategies in different regions. In addition, through documentation of the disparities within and between countries and regions, initiatives have been launched to foster change. Since the first survey, there has been an increase in the number of countries which have registries to document the burden of CKD or dialysis. For many, information about the burden of disease is the first step toward addressing care delivery issues, including prevention, delay of progression, and access to services. Worldwide collaboration in the documentation of kidney health and disease is an important step toward the goal of ensuring equitable access to kidney health worldwide.

Continuity of care: evaluating a multidisciplinary care model for people with early CKD via a nationwide population-based longitudinal study

OBJECTIVES

To control and prevent the burdens associated with chronic kidney disease (CKD), Taiwan's National Health Insurance Administration (NHIA) launched the 'early-CKD programme' in 2011 to extend care and education to patients with CKD. This study aims to evaluate the effectiveness of the early-CKD programme in terms of continuity of care (COC).

DESIGN AND PARTICIPANTS

This study used secondary data from 2010 to 2014 provided by the NHIA to identify 86 581 participants each for the intervention and control groups. Patients with CKD who participated in the early-CKD programme between 2011 and 2013 were defined as the intervention group. For the control group, propensity score matching was used to select patients with CKD who did not participate in the programme, but were seen by the same group of physicians.

INTERVENTION

A multidisciplinary care model for patients with early CKD launched in 2011.

PRIMARY OUTCOME MEASURES

Outcome variables included the continuity of care index (COCI), which measures a physician's COC; number of essential examinations; and resource utilisation. To better identify the difference between groups, we separated COCI into two groups based on mean: high (above mean) and low (below mean). A generalised estimating equation model was used to examine the effects of the early-CKD programme.

RESULTS

The programme significantly increased the number of essential examinations/tests administered to patients (β=0.61, p<0.001) and improved COCI between physicians and patients (OR=4.18, p<0.001). Medical expenses (β=1.03, p<0.001) and medication expenses (β=0.23, p<0.001) significantly increased after the programme was implemented, but patients' kidney-related hospitalisations and emergency department visits decreased (β=-0.13, p<0.001).

CONCLUSION

From the COC viewpoint, the programme in Taiwan showed a positive effect on COCI, number of essential examinations and resource utilisation.

Ethnic minority disparities in progression and mortality of pre-dialysis chronic kidney disease: a systematic scoping review

Background

There are a growing number of studies on ethnic differences in progression and mortality for pre-dialysis chronic kidney disease (CKD), but this literature has yet to be synthesised, particularly for studies on mortality.

Methods

This scoping review synthesized existing literature on ethnic differences in progression and mortality for adults with pre-dialysis CKD, explored factors contributing to these differences, and identified gaps in the literature. A comprehensive search strategy using search terms for ethnicity and CKD was taken to identify potentially relevant studies. Nine databases were searched from 1992 to June 2017, with an updated search in February 2020.

Results

8059 articles were identified and screened. Fifty-five studies (2 systematic review, 7 non-systematic reviews, and 46 individual studies) were included in this review. Most were US studies and compared African-American/Afro-Caribbean and Caucasian populations, and fewer studies assessed outcomes for Hispanics and Asians. Most studies reported higher risk of CKD progression in Afro-Caribbean/African-Americans, Hispanics, and Asians, lower risk of mortality for Asians, and mixed findings on risk of mortality for Afro-Caribbean/African-Americans and Hispanics, compared to Caucasians. Biological factors such as hypertension, diabetes, and cardiovascular disease contributed to increased risk of progression for ethnic minorities but did not increase risk of mortality in these groups.

Conclusions

Higher rates of renal replacement therapy among ethnic minorities may be partly due to increased risk of progression and reduced mortality in these groups. The review identifies gaps in the literature and highlights a need for a more structured approach by researchers that would allow higher confidence in single studies and better harmonization of data across studies to advance our understanding of CKD progression and mortality.

Clair Russell J, Pendergast J, Bhavsar N, Scialla J, Tyson CC, Wang W, Min YI, Young B, Boulware LE, Diamantidis CJ. Association of functional and structural social support with chronic kidney disease among African Americans: the Jackson Heart Study

BACKGROUND

There is limited evidence on the relationship between social support and renal outcomes in African Americans. We sought to determine the association of social support with prevalent chronic kidney disease (CKD) and kidney function decline in an African American cohort. We also examined whether age modifies the association between social support and kidney function decline.

METHODS

We identified Jackson Heart Study (JHS) participants with baseline (Exam in 2000-2004) functional and structural social support data via the Interpersonal Support Evaluation List (ISEL) and social network size questions, respectively. With ISEL as our primary exposure variable, we performed multivariable regression models to evaluate the association between social support and prevalent CKD [estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2 or urine albumin-creatinine ratio (ACR) ≥30 mg/g], eGFR decline, and rapid renal function decline (RRFD) (> 30% decrease in eGFR over approximately 10 years). All models were adjusted for baseline sociodemographics, diabetes, hypertension, smoking status, and body mass index; models for eGFR decline and RRFD were additionally adjusted for eGFR and ACR. In models for eGFR decline, we assessed for interaction between age and social support. For secondary analyses, we replaced ISEL with its individual domains (appraisal, belonging, self-esteem, and tangible) and social network size in separate models as exposure variables.

RESULTS

Of 5301 JHS participants, 4015 (76%) completed the ISEL at baseline. 843 (21%) had low functional social support (ISEL score < 32). Participants with low (vs. higher) functional social support were more likely to have lower income (47% vs. 28%), be current or former tobacco users (39% vs. 30%), have diabetes (25% vs. 21%) or CKD (14% vs. 12%). After multivariable adjustment, neither ISEL or social network size were independently associated with prevalent CKD, eGFR decline, or RRFD. Of the ISEL domains, only higher self-esteem was associated with lower odds of prevalent CKD [OR 0.94 (95% CI 0.89-0.99)]. The associations between social support measures and eGFR decline were not modified by age.

CONCLUSIONS

In this African-American cohort, social support was not associated with prevalent CKD or kidney function decline. Further inquiry of self-esteem's role in CKD self-management and renal outcomes is warranted.

Socioeconomic disadvantage and the risk of advanced chronic kidney disease: results from a cohort study with 1.4 million participants

Background

Several studies have investigated the effect of socioeconomic deprivation on cardiovascular disease (CVD) and diabetes; less is known about its effect on chronic kidney disease (CKD). We aimed to measure the association between deprivation, CKD Stages 4–5 and end-stage renal disease (ESRD) in a general population sample.

Methods

This observational study examined 1 405 016 participants from the English Clinical Practice Research Datalink (2000–14), linked to hospital discharge data and death certification. Deprivation was assessed according to the participant’s postcode. Cox models were used to estimate hazard ratios (HRs) for CKD Stages 4–5 and ESRD, adjusting for age and sex, and additionally for smoking status, body mass index, diabetes, systolic blood pressure, prior CVD and estimated glomerular filtration rate (eGFR) at baseline.

Results

During 7.5 years of median follow-up, 11 490 individuals developed CKD Stages 4–5 and 1068 initiated ESRD. After adjustment for age and sex, the HRs and confidence interval (CI) comparing those in the 20% most deprived of the population to the 20% least deprived were 1.76 (95% CI 1.68–1.84) and 1.82 (95% CI 1.56–2.12) for CKD Stages 4–5 and ESRD, respectively. Further adjustment for known risk factors and eGFR substantially attenuated these HRs. Adding our results to all known cohort studies produced a pooled relative risk of 1.61 (95% CI 1.42–1.83) for ESRD, for comparisons between highest to lowest categories of deprivation.

Conclusion

Socioeconomic deprivation is independently associated with an increased hazard of CKD Stages 4–5 and ESRD, but in large part may be mediated by known risk factors.

Serum 6-Bromotryptophan Levels Identified as a Risk Factor for CKD Progression

Background Metabolite levels reflect physiologic homeostasis and may serve as biomarkers of disease progression. Identifying metabolites associated with APOL1 risk alleles-genetic variants associated with CKD risk commonly present in persons of African descent-may reveal novel markers of CKD progression relevant to other populations.Methods We evaluated associations between the number of APOL1 risk alleles and 760 serum metabolites identified via untargeted profiling in participants of the African American Study of Kidney Disease and Hypertension (AASK) (n=588; Bonferroni significance threshold P<6.5×10^-5) and replicated findings in 678 black participants with CKD in BioMe, an electronic medical record-linked biobank. We tested the metabolite association with CKD progression in AASK, BioMe, and the Modification of Diet in Renal Disease (MDRD) Study.Results One metabolite, 6-bromotryptophan, was significant in AASK (P=4.7×10^-5) and replicated in BioMe (P=5.7×10^-3) participants, with lower levels associated with more APOL1 risk alleles. Lower levels of 6-bromotryptophan were associated with CKD progression in AASK and BioMe participants and in white participants in the MDRD Study, independent of demographics and clinical characteristics, including baseline GFR (adjusted hazard ratio per two-fold higher 6-bromotryptophan level, AASK, 0.76; 95% confidence interval [95% CI], 0.64 to 0.91; BioMe, 0.61; 95% CI, 0.43 to 0.85; MDRD, 0.52; 95% CI, 0.34 to 0.79). The interaction between the APOL1 risk alleles and 6-bromotryptophan was not significant. The identity of 6-bromotryptophan was confirmed in experiments comparing its molecular signature with that of authentic standards of other bromotryptophan isomers.Conclusions Serum 6-bromotryptophan is a consistent and novel risk factor for CKD progression.

Ethnicity matching and outcomes after kidney transplantation in the United Kingdom

Background

Kidneys from non-white donors have inferior outcomes, but it is unclear if ethnicity matching between donors and recipients achieves better post kidney transplant outcomes.

Methods

We undertook a retrospective, population cohort study utilising UK Transplant Registry data. The cohort comprised adult, kidney-alone, transplant recipients receiving their first kidney transplant between 2003–2015, with data censored at 1^st October 2016. We included 27,970 recipients stratified into white (n = 23,215), black (n = 1,679) and south Asian (n = 3,076) ethnicity, with median post-transplant follow-up of 1,676 days (IQR 716–2,869 days). Unadjusted and adjusted Cox regression survival analyses were performed to investigate ethnicity effect on risk for graft loss and mortality.

Results

In unadjusted analyses, matched ethnicity between donors-recipients resulted in better outcomes for delayed graft function, one-year creatinine, graft and patient survival but these differed by ethnicity matches. Compared to white-to-white transplants, risk for death-censored graft loss was higher in black-to-black and similar among Asian-to-Asian transplants, but mortality risk was lower for both black-to-black and Asian-to-Asian transplants. In Cox regression models, compared to white donors, we observed higher risk for graft loss with both south Asian (HR 1.38, 95%CI 1.12–1.70, p = 0.003) and black (HR 1.66, 95%CI 1.30–2.11, p<0.001) donated kidneys independent of recipient ethnicity. We observed no mortality difference with south Asian donated kidneys but increased mortality with black donated kidneys (HR 1.68, 95%CI 1.21–2.35, p = 0.002). Matching ethnicities made no significant difference in any Cox regression model. Similar results were observed after stratifying our analysis by living and deceased-donor kidney transplantation.

Conclusions

Our data confirm inferior outcomes associated with non-white kidney donors for kidney transplant recipients of any ethnicity in a risk-adjusted model for the United Kingdom population. However, contrary to non-renal transplant literature, we did not identify any survival benefits associated with donor-recipient ethnicity matching.

Ethnic differences in the progression of chronic kidney disease and risk of death in a UK diabetic population: an observational cohort study

OBJECTIVE

To determine ethnic differences in the progression of chronic kidney disease (CKD) and risk of end-stage renal failure (ESRF) and death in adults with type 2 diabetes mellitus (T2DM), and to identify predictors of rapid renal decline.

DESIGN

Observational community-based cohort study undertaken from 2006 to 2016 with nested case-control study.

SETTING

135 inner London primary care practices contributing to the east London Database.

PARTICIPANTS

General practice-registered adults aged 25-85 years with established T2DM and CKD at baseline.

OUTCOMES

The annual rate of renal decline was compared between white, south Asian and black groups, and stratified by proteinuria and raised blood pressure (BP) at baseline. Predictors of rapid renal decline were identified in a nested case-control study. Cox proportional hazards regression was used to determine ethnic differences in the risk of ESRF and death.

RESULTS

Age-sex adjusted annual decline was greatest in the Bangladeshi population. There was stepwise increase in the rate of decline when stratifying the cohort by baseline proteinuria and BP control, with south Asian groups being most sensitive to the combined effect of proteinuria and raised BP after accounting for key confounders.The odds of rapid renal decline were increased for individuals of Bangladeshi, African and Caribbean ethnicity, those with hypertension, proteinuria, cardiovascular disease and with increasing duration of diabetes. Rapid progression was more frequent in younger age groups. Risk of developing ESRF was highest in the black group compared with the white group (HR 1.88, 95% CI 1.11 to 3.19). Risk of death from any cause was 29% lower in the south Asian group compared with the white group (HR 0.71, 95% CI 0.56 to 0.91).

CONCLUSIONS

Proteinuria and hypertension trigger accelerated estimated glomerular filtration rate decline differentially by ethnicity. Active monitoring of younger adults, who have greater odds of rapid progression and the most to gain from interventions, is essential.

Serum creatinine elevation after renin-angiotensin system blockade and long term cardiorenal risks: cohort study

Objective To examine long term cardiorenal outcomes associated with increased concentrations of creatinine after the start of angiotensin converting enzyme inhibitor/angiotensin receptor blocker treatment.Design Population based cohort study using electronic health records from the Clinical Practice Research Datalink and Hospital Episode Statistics.Setting UK primary care, 1997-2014.Participants Patients starting treatment with angiotensin converting enzyme inhibitors or angiotensin receptor blockers (n=122 363).Main outcome measures Poisson regression was used to compare rates of end stage renal disease, myocardial infarction, heart failure, and death among patients with creatinine increases of 30% or more after starting treatment against those without such increases, and for each 10% increase in creatinine. Analyses were adjusted for age, sex, calendar period, socioeconomic status, lifestyle factors, chronic kidney disease, diabetes, cardiovascular comorbidities, and use of other antihypertensive drugs and non-steroidal anti-inflammatory drugs.Results Among the 2078 (1.7%) patients with creatinine increases of 30% or more, a higher proportion were female, were elderly, had cardiorenal comorbidity, and used non-steroidal anti-inflammatory drugs, loop diuretics, or potassium sparing diuretics. Creatinine increases of 30% or more were associated with an increased adjusted incidence rate ratio for all outcomes, compared with increases of less than 30%: 3.43 (95% confidence interval 2.40 to 4.91) for end stage renal disease, 1.46 (1.16 to 1.84) for myocardial infarction, 1.37 (1.14 to 1.65) for heart failure, and 1.84 (1.65 to 2.05) for death. The detailed categorisation of increases in creatinine concentrations (<10%, 10-19%, 20-29%, 30-39%, and ≥40%) showed a graduated relation for all outcomes (all P values for trends <0.001). Notably, creatinine increases of less than 30% were also associated with increased incidence rate ratios for all outcomes, including death (1.15 (1.09 to 1.22) for increases of 10-19% and 1.35 (1.23 to 1.49) for increases of 20-29%, using <10% as reference). Results were consistent across calendar periods, across subgroups of patients, and among continuing users.Conclusions Increases in creatinine after the start of angiotensin converting enzyme inhibitor/angiotensin receptor blocker treatment were associated with adverse cardiorenal outcomes in a graduated relation, even below the guideline recommended threshold of a 30% increase for stopping treatment.

Adherence to guidelines for creatinine and potassium monitoring and discontinuation following renin-angiotensin system blockade: a UK general practice-based cohort study

OBJECTIVES

To examine adherence to serum creatinine and potassium monitoring and discontinuation guidelines following initiation of treatment with ACE inhibitors (ACEI) or angiotensin receptor blockers (ARBs); and whether high-risk patients are monitored.

DESIGN

A general practice-based cohort study using electronic health records from the UK Clinical Practice Research Datalink and Hospital Episode Statistics.

SETTING

UK primary care, 2004-2014.

SUBJECTS

223 814 new ACEI/ARB users.

MAIN OUTCOME MEASURES

Proportion of patients with renal function monitoring before and after ACEI/ARB initiation; creatinine increase ≥30% or potassium levels >6 mmol/L at first follow-up monitoring; and treatment discontinuation after such changes. Using logistic regression models, we also examined patient characteristics associated with these biochemical changes, and with follow-up monitoring within the guideline recommendation of 2 weeks after treatment initiation.

RESULTS

10% of patients had neither baseline nor follow-up monitoring of creatinine within 12 months before and 2 months after initiation of an ACEI/ARB, 28% had monitoring only at baseline, 15% only at follow-up, and 47% both at baseline and follow-up. The median period between the most recent baseline monitoring and drug initiation was 40 days (IQR 12-125 days). 34% of patients had baseline creatinine monitoring within 1 month before initiating therapy, but <10% also had the guideline-recommended follow-up test recorded within 2 weeks. Among patients experiencing a creatinine increase ≥30% (n=567, 1.2%) or potassium level >6 mmol/L (n=191, 0.4%), 80% continued treatment. Although patients with prior myocardial infarction, hypertension or baseline potassium >5 mmol/L were at high risk of ≥30% increase in creatinine after ACEI/ARB initiation, there was no evidence that they were more frequently monitored.

CONCLUSIONS

Only one-tenth of patients initiating ACEI/ARB therapy receive the guideline-recommended creatinine monitoring. Moreover, the vast majority of the patients fulfilling postinitiation discontinuation criteria for creatinine and potassium increases continue on treatment.

Progression of Kidney Disease in Indigenous Australians: The eGFR Follow-up Study

BACKGROUND AND OBJECTIVES

Indigenous Australians experience a heavy burden of CKD. To address this burden, the eGFR Follow-Up Study recruited and followed an Indigenous Australian cohort from regions of Australia with the greatest ESRD burden. We sought to better understand factors contributing to the progression of kidney disease. Specific objectives were to assess rates of progression of eGFR in Indigenous Australians with and without CKD and identify factors associated with a decline in eGFR.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This observational longitudinal study of Indigenous Australian adults was conducted in >20 sites. The baseline cohort was recruited from community and primary care clinic sites across five strata of health, diabetes status, and kidney function. Participants were then invited to follow up at 2-4 years; if unavailable, vital status, progression to RRT, and serum creatinine were obtained from medical records. Primary outcomes were annual eGFR change and combined renal outcome (first of ≥30% eGFR decline with follow-up eGFR<60 ml/min per 1.73 m(2), progression to RRT, or renal death).

RESULTS

Participants (n=550) were followed for a median of 3.0 years. Baseline and follow-up eGFR (geometric mean [95% confidence interval], 83.9 (80.7 to 87.3) and 70.1 (65.9 to 74.5) ml/min per 1.73 m(2), respectively. Overall mean annual eGFR change was -3.1 (-3.6 to -2.5) ml/min per 1.73 m(2). Stratified by baseline eGFR (≥90, 60-89, <60 ml/min per 1.73 m(2)), annual eGFR changes were -3.0 (-3.6 to -2.4), -1.9 (-3.3 to -0.5), and -5.0 (-6.5 to -3.6) ml/min per 1.73 m(2). Across baseline eGFR categories, annual eGFR decline was greatest among adults with baseline albumin-to-creatinine ratio (ACR) >265 mg/g (30 mg/mmol). Baseline determinants of the combined renal outcome (experienced by 66 participants) were higher urine ACR, diabetes, lower measured GFR, and higher C-reactive protein.

CONCLUSIONS

The observed eGFR decline was three times higher than described in nonindigenous populations. ACR was confirmed as a powerful predictor for eGFR decline across diverse geographic regions.

Ethnic disparities in risk of cardiovascular disease, end-stage renal disease and all-cause mortality: a prospective study among Asian people with Type 2 diabetes

AIM

To study prospectively the ethnic-specific risks of cardiovascular disease, end-stage renal disease and all-cause mortality in patients with Type 2 diabetes mellitus among native Asian subpopulations.

METHODS

A total of 2337 subjects with Type 2 diabetes (70% Chinese, 17% Malay and 13% Asian Indian) were followed for a median of 4.0 years. Time-to-event analysis was used to study the association of ethnicity with adverse outcomes.

RESULTS

Age- and gender-adjusted hazard ratios for cardiovascular disease in ethnic Malay and Asian Indian subjects were 2.01 (1.40-2.88; P<0.0001) and 1.60 (1.07-2.41; P=0.022) as compared with Chinese subjects. Adjustment for conventional cardiovascular disease risk factors, including HbA1c , blood pressure and lipid profile, slightly attenuated the hazards in Malay (1.82, 1.23-2.71; P=0.003) and Asian Indian subjects (1.47, 0.95-2.30; P=0.086); However, further adjustment for baseline renal function (estimated GFR) and albuminuria weakened the cardiovascular disease risks in Malay (1.48, 0.98-2.26; P=0.065) but strengthened that in Asian Indian subjects (1.81, 1.14-2.87; P=0.012). Competing-risk regression showed that the age- and gender-adjusted sub-distribution hazard ratio for end-stage renal disease was 1.87 (1.27-2.73; P=0.001) in Malay and 0.39 (0.18-0.83; P=0.015) in Asian Indian subjects. Notably, the difference in end-stage renal disease risk among the three ethnic groups was abolished after further adjustment for baseline estimated GFR and albuminuria. There was no significant difference in risk of all-cause mortality among the three ethnic groups.

CONCLUSIONS

Risks of cardiovascular and end-stage renal diseases in native Asian subjects with Type 2 diabetes vary substantially among different ethnic groups. Differences in prevalence of diabetic kidney disease may partially explain the ethnic disparities.

Changes in characteristics and management of Asian and Anglo-Celts with type 2 diabetes over a 15-year period in an urban Australian community: The Fremantle Diabetes Study

BACKGROUND

The aim of the present study was to determine temporal changes in characteristics and management of Asians with type 2 diabetes (T2D) compared with those of the majority Anglo-Celt (AC) patients in an urban Australian community.

METHODS

Cross-sectional data from the observational Fremantle Diabetes Study (FDS) collected in 1993-96 (Phase I; FDS1) and 2008-11 (Phase II; FDS2) were analyzed for patients classified as Asian (n = 44 and 65 in FDS1 and FDS2, respectively) or AC (n = 796 and 793, respectively). Between-group differences in changes in key variables between FDS phases were analyzed by generalized linear modeling with adjustment for age and gender.

RESULTS

Asians patients were significantly younger at diagnosis and recruitment and had a lower body mass index and smaller waist circumference than the AC participants in both FDS phases. They were also less likely to be treated for hypertension. Cardiovascular risk factors and their management and macrovascular complications were similar in the two groups over time. A greater propensity to retinopathy with Asian ethnicity in FDS1 (27.3% vs 13.5%; P = 0.23) was attenuated in FDS2 (23.7% vs 19.0%; P = 0.39). Asians had a significantly lower prevalence of peripheral sensory neuropathy in FDS2 (33.8% vs 63.3%; P < 0.001; adjusted P = 0.011 for between-group temporal change).

CONCLUSIONS

There were persistent differences between the phenotypic features of Asian migrants with T2D versus AC patients in an Australian urban community over 15 years of follow-up, but management of diabetes and non-glycemic risk factors remained comparable. Ethnicity-specific differences in susceptibility to microvascular complications should be considered in clinical management.

Hispanic Americans living in the United States and their risk for obesity, diabetes and kidney disease: Genetic and environmental considerations

The Hispanic American, the largest minority population in the United States, is at increased risk for obesity, diabetes and end-stage renal disease. Here we review genetic and environmental factors that might account for their increased risk for these conditions. Whereas many environmental and genetic factors have important roles in driving the increased risk for obesity and kidney disease in this population, a case is made that excessive intake of sugary beverages is a contributory cause. Studies focusing on decreasing intake of sugary beverages among the Hispanic American could potentially reduce renal and cardiovascular complications in this population.

End stage renal disease risk and neighbourhood deprivation: a nationwide cohort study in Sweden

BACKGROUND

Chronic kidney disease has been associated with socioeconomic disparities and neighbourhood deprivation. We aimed to determine whether there is an association between neighbourhood deprivation and end stage renal disease (ESRD), and whether this association is independent of individual-level sociodemographic factors and comorbidities.

METHODS

National Swedish data registers were used. The entire Swedish population aged 20-69 years was followed from January 1, 2001 until December 31, 2010. Data were analysed by multilevel logistic regression, with individual-level sociodemographic factors (age, marital status, family income, education level, country of birth, urban/rural status, and mobility) and comorbidities at the first level and neighbourhood deprivation at the second level.

RESULTS

Neighbourhood deprivation was significantly associated with ESRD (age-adjusted odds ratio [OR] 1.45, 95% confidence interval [CI] 1.34-1.56 in men and OR 1.59, 95% CI 1.44-1.75 in women). The ORs for ESRD in men and women living in the most deprived neighbourhoods remained significantly increased when adjusted for age and individual-level sociodemographic factors (OR 1.25, 95% CI 1.15-1.35 in men and OR 1.30, 95% CI 1.17-1.44 in women). In the full model, which took account of sociodemographic factors and comorbidities, the ORs for ESRD remained significantly increased (OR 1.17, 95% CI 1.07-1.27 in men and OR 1.18, 95% CI 1.06-1.31 in women).

CONCLUSION

Neighbourhood deprivation is independently associated with ESRD in both men and women irrespective of individual-level sociodemographic factors and comorbidities.

Microcirculatory marker for the prediction of renal end points: a prospective cohort study in patients with chronic kidney disease stage 2 to 4

Retinal arteriolar narrowing reflects aging, hypertension, chronic kidney disease (CKD), and other vascular processes. We examined the predictive value of retinal arteriolar narrowing alone and in combination with albuminuria on renal disease progression in CKD. A white CKD stage 2 to 4 cohort of 164 men and women (60.8±13.8 years) underwent retinal photography and determination of albuminuria. The calibers of all retinal arterioles were measured after digital conversion of the photographs. Cases of incident renal end points defined as 50% renal function loss and start of renal replacement therapy were identified and validated by case record reviews. Over an average period of 1410 (range, 106-1606) days, 25 patients with CKD had incident renal end points. Kaplan-Meier analysis revealed that patients with CKD within the tertile of narrowest arterioles had more renal end points (log-rank P<0.001). Cox regression analysis confirmed this before (β=1.183±0.411) and after adjusting for age and baseline renal function (β=1.204±0.416). With respect to renal end points, a significant interaction was present between narrow arterioles and albuminuria. The relative risk for renal end points of narrow arterioles was 3.7 (1.7-8.4), of albuminuria was 5.4 (2.5-12.0), and of combined narrow arterioles and albuminuria was 16.2 (4.6-57.2). Hence retinal arteriolar narrowing is related to incident renal end points. Narrow arterioles and albuminuria reveal a synergistic predictive value. The findings support a leading role of the microvasculature in the pathogenesis of renal disease progression. They also suggest that retinal photography in combination with albuminuria determination may be useful for risk stratification with respect to renal disease progression in patients with CKD stage 2 to 4.

APOL1 risk variants, race, and progression of chronic kidney disease

BACKGROUND

Among patients in the United States with chronic kidney disease, black patients are at increased risk for end-stage renal disease, as compared with white patients.

METHODS

In two studies, we examined the effects of variants in the gene encoding apolipoprotein L1 (APOL1) on the progression of chronic kidney disease. In the African American Study of Kidney Disease and Hypertension (AASK), we evaluated 693 black patients with chronic kidney disease attributed to hypertension. In the Chronic Renal Insufficiency Cohort (CRIC) study, we evaluated 2955 white patients and black patients with chronic kidney disease (46% of whom had diabetes) according to whether they had 2 copies of high-risk APOL1 variants (APOL1 high-risk group) or 0 or 1 copy (APOL1 low-risk group). In the AASK study, the primary outcome was a composite of end-stage renal disease or a doubling of the serum creatinine level. In the CRIC study, the primary outcomes were the slope in the estimated glomerular filtration rate (eGFR) and the composite of end-stage renal disease or a reduction of 50% in the eGFR from baseline.

RESULTS

In the AASK study, the primary outcome occurred in 58.1% of the patients in the APOL1 high-risk group and in 36.6% of those in the APOL1 low-risk group (hazard ratio in the high-risk group, 1.88; P<0.001). There was no interaction between APOL1 status and trial interventions or the presence of baseline proteinuria. In the CRIC study, black patients in the APOL1 high-risk group had a more rapid decline in the eGFR and a higher risk of the composite renal outcome than did white patients, among those with diabetes and those without diabetes (P<0.001 for all comparisons).

CONCLUSIONS

Renal risk variants in APOL1 were associated with the higher rates of end-stage renal disease and progression of chronic kidney disease that were observed in black patients as compared with white patients, regardless of diabetes status. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.).

Differences in progression to ESRD between black and white patients receiving predialysis care in a universal health care system

BACKGROUND AND OBJECTIVES

Studies performed in the United States showed that blacks progress from CKD to ESRD faster than do whites. Possible explanations are differences in health care system factors. This study investigated whether progression is also faster in a universal health care system, where all patients receive comparable care.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from the PREdialysis PAtient REcord study, a multicenter follow-up study of patients with CKD who started predialysis care in The Netherlands (1999-2011), were analyzed. Time-dependent Cox proportional hazards models were used to estimate the hazard ratio (HR) for starting renal replacement therapy (RRT), and linear mixed models were used to compare renal function decline (RFD) between blacks and whites. To explore possible mechanisms, analyses were adjusted for patient characteristics.

RESULTS

At initiation of predialysis care, blacks (n=49) were younger and had more diabetes mellitus, higher proteinuria levels, and a higher estimated GFR than whites (n=946). Median follow-up time in months was similar (blacks: 13.9 [boundaries of interquartile range (IQR), 5.3 to 19.5]; whites: 13.1 [IQR, 5.1 to 24.0]). For blacks compared with whites, the crude HR for starting RRT within the first 15 months was 0.86 (95% confidence interval [CI], 0.55 to 1.34) and from 15 months onward, 1.93 (95% CI, 1.02 to 3.68), which increased after adjustment. RFD was faster by 0.18 (95% CI, 0.05 to 0.32) ml/min per 1.73 m(2) per month in blacks compared with whites.

CONCLUSION

Blacks receiving predialysis care in a universal health care system have faster disease progression than whites, suggesting that health care system factors have a less influential role than had been thought in explaining black-white differences.

Progression of chronic kidney disease in a multi-ethnic community cohort of patients with diabetes mellitus

AIMS

Ethnicity is a risk factor for the prevalence of severe chronic kidney disease among patients with diabetes. We studied the effect of ethnicity on progression of chronic kidney disease in people with diabetes managed in community settings.

METHODS

A 5-year retrospective, community-based cohort study of 3855 people with diabetes mellitus of white, black or South Asian ethnicity with an estimated glomerular filtration rate of < 60 ml min⁻¹ 1.73 m⁻² was undertaken. From 135 general practices in east London, all cases with at least 3 years clinical data were included. Using repeated-measures analysis, the annual decline in estimated glomerular filtration rate was calculated. Comparisons between the rate of decline in the three main ethnic groups, with and without proteinuria at baseline, were made.

RESULTS

The annual adjusted decline in estimated glomerular filtration rate for this cohort was 0.85 ml min⁻¹ 1.73 m⁻². The rate of chronic kidney disease progression was significantly greater in South Asian groups (-1.01 ml min⁻¹ 1.73 m⁻²) compared with white groups (-0.70 ml min⁻¹ 1.73 m⁻²) (P = 0.001). For those with proteinuria at baseline, the annual decline was greater at 2.05 ml min⁻¹ 1.73 m⁻², with both South Asian and black groups having a significantly faster rate of decline than white groups.

CONCLUSIONS

For patients with diabetes and chronic kidney disease managed in primary care, the annual decline of renal function is less than previously thought and approximates the age-related annual decline of 1 ml min⁻¹ 1.73 m⁻². Patients with proteinuria and those of South Asian and Black ethnicity need additional monitoring as they are at greater risk of rapid chronic kidney disease progression.

Does a medical management program for CKD patients postpone renal replacement therapy and mortality? A 5-year-cohort study

Background

Many countries have started screening and prevention programs for chronic kidney disease (CKD). However, one of the main concerns of health authorities is whether management strategies for diagnosed CKD patients can decrease mortality or morbidity. This study aimed to investigate the effect of two competing clinical strategies of treatments under nephrologists’ supervision compared with no treatment on the frequency of the need to start renal replacement therapy (RRT) and mortality in CKD patients.

Methods

Our cohort comprised consecutive newly diagnosed patients with CKD in an outpatient clinic in Tehran between October 2002 and October 2011. CKD Patient enrollment occurred if two criteria of high plasma creatinine level and chronicity of renal disease by at least 3 months of clinical history or small sized kidneys in ultrasound findings were met. Demographic data and time of RRT or mortality in patients who had been followed up regularly were compared with those in the control group. The control group included those patients who did not attend a nephrology clinic to receive CKD management package for at least 1 year during the study period.

Results

The cohort included 76 patients in the control group and 389 patients in the supervised group. The mean age of the patients was 61.33±14.9 years (16–95 years). The ratio of males/females was 1.47 (277/188). The mean follow-up in the control and supervised groups was 33.29±20.50 (7–111) and 36.03±25.24 (6–124) months , respectively, and the total patient years of follow-up was 1382.3. A substantial number of patients survived without RRT until the first year of follow up (96%) in both groups, but afterward, those in the control group had more deaths or need to start RRT in comparison with those who received medical advice (20 vs. 67 months; p= 0.029). This cohort also showed a higher survival and a longer time to show a GFR of less than 15 cc/min (84 vs 34 months, p<0.0001) in patients who had been under physician supervision compared with the control group.

Conclusions

Active follow-up of CKD patients appears to significantly decrease the risk of death or progression to end-stage renal disease and the requirement to start renal replacement therapy.

Renal function trajectory is more important than chronic kidney disease stage for managing patients with chronic kidney disease

Management of patients with chronic kidney disease (CKD) emphasizes a current level of function as calculated from the modification of diet in renal disease glomerulofiltration rate equations (eGFR) and proteinuria for staging of CKD. Change in a patient's eGFR over time (renal function trajectory) is an additional and potentially more important consideration in deciding which patients will progress to the point where they will require renal replacement therapy (RRT). Many patients with CKD 3-5 have stable renal function for years. Proteinuria/albuminuria is a primary determinant of renal trajectory which may be slowed by medications that decrease proteinuria and/or aggressively lower blood pressure. A renal trajectory of >3 ml/min/1.73 m(2)/year may relate to a need for closer renal follow-up and increased morbidity and mortality. Additional CKD population-based studies need to examine the relationship of renal trajectory to: baseline renal function; acute kidney injury episodes; age, race, sex and primary etiologies of renal disease; blood pressure control and therapies; dietary protein intake; blood glucose control in diabetics and the competitive risk of death versus the requirement for renal replacement therapy. In the elderly CKD 4 population with significant comorbidities and slow decline in renal function, the likelihood of death prior to the need for RRT should be considered before placing AV access for dialysis. Prediction models of renal progression must account for the competitive risk of death as well as stable or improved renal function to be clinically useful.

Mortality and renal function decline among a community-based Chinese population with normal or mildly impaired renal function

BACKGROUND

Longitudinal studies of the mortality and renal outcomes among the population with an estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m(2) and among the elderly are limited, especially in developing countries.

METHODS

This prospective cohort study included 1563 residents aged 59.5 ± 9.4 years from an urban district of Beijing, China. All participants had an eGFR >30 mL/min/1.73 m(2). Urinary albumin-to-creatinine ratio and eGFR were assessed at baseline, and their relation with mortality and renal function decline after a 4-year follow-up were analyzed.

RESULTS

During 4 years (6142 person-years) of follow-up, 59 deaths occurred (9.6 per 1000 person-years). After adjusting for potential confounders, albuminuria was associated with increased risk of mortality, with an odds ratio (OR) of 3.09 [95% confidence interval (CI) 1.53-6.26]. Altogether 183 patients (12.3%) developed renal function decline, with a median change of eGFR of -20.0 mL/min/1.73 m(2). Presence of albuminuria was significantly associated renal function decline, with an OR of 1.79 (95% CI 1.02-3.15). Plasma uric acid (OR = 1.25/59 μmol/L increase, 95% CI 1.10-1.43) and age (OR = 1.35/5 years increase, 95% CI 1.22-1.50) was also independently associated with renal function decline. Baseline eGFR was not significantly associated with either mortality or renal function decline in our analysis.

CONCLUSIONS

Compared with eGFR, albuminuria is a strong independent predictor for both mortality and renal function decline among a Chinese population with normal or mildly impaired renal function. Furthermore, plasma uric acid level and age are also independently associated with renal function decline and therefore may be used for identifying patients at higher risk of chronic kidney disease progression.