Classification of chronic kidney disease ten years on: what have we learnt and what do we need to do now?

Over the past 10 years, chronic kidney disease (CKD) has become known as a common long-term condition, that affects around 13% of adults worldwide (1). CKD is defined as abnormalities of kidney structure or function, present for more than 3 months, and classified into five stages (2) using a blood test for estimated glomerular filtration rate (eGFR) and also a urine test for albumin–creatine ratio (ACR). To accurately diagnose CKD and improve health outcomes, it is important that both blood and urine tests are performed. CKD is associated with an increased risk of cardiovascular disease and also an increased risk for progression to advanced kidney disease that requires renal replacement therapy (dialysis or transplantation