Kidney progression project (KiPP): Protocol for a longitudinal cohort study of progression in chronic kidney disease of unknown etiology in Sri Lanka.

Over the last two decades, a global epidemic of chronic kidney disease of unknown etiology (CKDu) has emerged in rural, arid, agricultural, lowland areas. Endemic regions have reported 15 to 20% prevalence among residents aged 30-60 years. CKDu is a progressive and irreversible disease resulting in renal failure and death in the absence of dialysis or a kidney transplant.