The full spectrum of renal disease can range from a rapid decline in renal function manifesting as acute kidney injury (AKI), a more gradual worsening of renal function known as chronic kidney disease (CKD) or a complete failure of the kidneys leading to end-stage renal disease (ESRD).
CKD is defined as abnormalities of kidney structure or function, which persist for greater than 3 months. The function of the kidney is assessed by glomerular filtration rate (GFR) and a persistent decline in GFR to less than 60 mL/min / 1.73 m2 characterizes someone as having kidney disease.1,2 CKD can also be a result of structural damage to the kidney with manifestations like albuminuria, hematuria, and tubular damage causing loss of electrolytes or damage detected on imaging or pathology. CKD is divided into stages based on GFR as shown in Fig. 54-1.1 Moreover the degree of albuminuria predicts the risk for disease progression as described in Fig. 54-1.1
Risk of CKD disease progression-based on GFR and albuminuria. Some patients with CKD have further progression of their disease and reach a diagnosis of ESRD, requiring some form of renal replacement therapy like peritoneal dialysis, hemodialysis, or renal transplantation. (Source: Reproduced with permission from Kidney Int Suppl. 2013;3:5–14.)
Burden of Chronic Kidney Disease and End-stage Renal Disease
The prevalence of CKD worldwide is estimated to be between 11% and 13%,3 and to be 14.8% among adults in the United States with 14.8%.4 The prevalence of CKD varies based on gender and race with women and African Americans having a higher prevalence.5 With the increase in the prevalence of diabetes and increasing age of the population, the incidence of CKD is expected to increase further as diabetes is the leading cause of CKD.6
Not only is CKD a prevalent problem but these patients have multiple other comorbidities. It has been estimated that 40% of individuals with CKD also have diabetes and 32% have hypertension.4 One of the major causes of morbidity and mortality in the CKD population is cardiovascular disease (CVD). Studies have shown a 10–47% incidence of CVD in patients with CKD and lower eGFR and increased albuminuria are independent predictors of CVD in this patient population.7–11 As a result of these comorbidities, the quality of life and life expectancy for most of these patients are is quite low and patients on dialysis have a much higher mortality rate compared to the general Medicare population.6
Moreover, renal replacement therapy (i.e., dialysis and kidney transplantation) is expensive procedures and Centers for Medicare and Medicaid Services extends coverage to all patients with ESRD who require dialysis or transplantation. This accounts for ...