Is the problem with the vehicle or the destination? Does high-dose ESA or high haemoglobin contribute to poor outcomes in CKD?

Randomized controlled trials have consistently demonstrated adverse outcomes from targeting higher haemoglobin levels in chronic kidney disease patients treated with erythropoiesis-stimulating agents (ESA). In contrast, observational studies have shown better survival in patients achieving high haemoglobin. Consequently, there is ongoing uncertainty as to whether high haemoglobin or high ESA dose contributes to poor outcomes in ESA-treated chronic kidney disease patients. The objectives of this article are to review the available evidence pertaining to this contentious area, provide recommendations where possible and suggest directions for future research efforts.