Early chronic kidney disease: diagnosis, management and models of care

Abstract

Chronic kidney disease (CKD) is prevalent in many countries, and the costs associated with the care of patients with end-stage renal disease (ESRD) are estimated to exceed US$1 trillion globally. The clinical and economic rationale for the design of timely and appropriate health system responses to limit the progression of CKD to ESRD is clear. Clinical care might improve if early-stage CKD with risk of progression to ESRD is differentiated from early-stage CKD that is unlikely to advance. The diagnostic tests that are currently used for CKD exhibit key limitations; therefore, additional research is required to increase awareness of the risk factors for CKD progression. Systems modelling can be used to evaluate the impact of different care models on CKD outcomes and costs. The US Indian Health Service has demonstrated that an integrated, system-wide approach can produce notable benefits on cardiovascular and renal health outcomes. Economic and clinical improvements might, therefore, be possible if CKD is reconceptualized as a part of primary care. This Review discusses which early CKD interventions are appropriate, the optimum time to provide clinical care, and the most suitable model of care to adopt.

Figure 1

The prevalence of CKD by stage in the USA, 1988–2012. The prevalence estimates are based on samples of non-institutionalized adults (aged 20 years or older) who participated in the National Health and Nutrition Examination Survey (NHANES) during the study years. The sample sizes varied across 1988–1994 (n=15,488), 1999–2004 (n=13,233), and 2007–2012 (n=15,502). The proteinuria measures were based on albumin-creatinine ratios from spot morning urine samples. The estimated glomerular filtration rates were calculated using the CKD-EPI creatinine formula. Stage 3 corresponds to a glomerular filtration rate of 30-59 mL/min/1.73 m². The error bars show the 95% confidence intervals. The data reported here have been supplied by the United States Renal Data System (USRDS). The interpretation and reporting of these data are the responsibility of the authors and in no way should be seen as an official policy or interpretation of the U.S. government.

Figure 2

The breakdown of CKD by stage (1–5) in selected countries with data available from the 2000's. Stage 3 corresponds to a glomerular filtration rate of 30-59 mL/min/1.73 m². The Chinese study used a sample of individuals from Beijing, the Indian study used a sample from thirteen academic and private medical centres located throughout the country, and the Korean study used a sample from seven urban cities. The other studies used nationally-representative samples. For Japan, the prevalence estimate for stage 4 includes both stages 4 and 5. All studies either sampled adults aged ≥18 years or ≥20 years, except for the Korean study which included adults aged ≥35 years. All studies used a version of the four-variable MDRD study equation to determine eGFR, except for the USA study data which used the CKD-EPI creatinine formula. The Chinese, Korean, Spanish, and USA studies measured proteinuria by using the spot morning urinary albumin-creatinine ratio. The remaining studies used a urine dipstick analysis for proteinuria. The Chinese study also measured haematuria by dipstick test.

Figure 3

Comparison of CKD prevalence by eGFR formula (CKD-EPI creatinine vs. four-variable MDRD study) in the USA, 1999–2004. The prevalence estimates are based on samples of non-institutionalized adults (aged 20 years or older) who participated in the National Health and Nutrition Examination Survey (NHANES) during these years (n=13,233). The CKD-EPI data reported here have been supplied by the United States Renal Data System (USRDS). The interpretation and reporting of these data are the responsibility of the authors and in no way should be seen as an official policy or interpretation of the U.S. government. The four-variable MDRD study data were reported by Coresh et al (2007). Both studies used measures of albumin-creatinine ratios from spot morning urine samples. Stage 3 corresponds to a glomerular filtration rate of 30–59 mL/min/1.73 m². The error bars show the 95% confidence intervals. Coresh et al (2007) did not estimate the prevalence of stage 5 with the MDRD study equation as they deemed that “estimates of this stage are likely to be unreliable due to the small number of individuals and the likelihood that many of these individuals are ill or receiving dialysis and would have a low response rate.”

Figure 4

An integrated care continuum for CKD that is consistent with the chronic care model. Abbreviations: AVF, arteriovenous fistula; CKD, chronic kidney disease; ESRD, end-stage renal disease; RRT, renal replacement therapy.