What is early CKD?
An international classification of CKD has identified five stages. Early CKD is described as stages 1–3. Stages 1 and 2 are characterized by: structural abnormalities, presence of persistent proteinuria or albuminuria or haematuria. Stage 3 is characterized by impaired kidney function as defined by estimated glomerular filtration rate (eGFR) of between 30 and 59 ml/min/1.73 m2 on at least two occasions at a minimal interval of 3 months. Using this definition, it is estimated that as many as 10% of the UK adult population have early CKD, of whom half will have stage 3. This increases with age to ∼20% over 65 years and >30% over 80 years.
