Figure 1. Flow diagram for the selection of patients in the analysis.

Patients were excluded if the age, follow-up, laboratory record, or medication record criteria could not be fulfilled. Patients who reached death or received renal replacement therapy in less than 3 months were also excluded. Renal replacement therapy includes hemodialysis, peritoneal dialysis, and renal transplantation. ESA non-user was defined as not receiving any ESA during follow-up, while ESA user as receiving ESA in any given month. Abbreviations: CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; ESA, erythropoiesis-stimulating agent; Hb, hemoglobin; UPCR, urine protein-creatinine ratio.