GSTM1 and stage 5 chronic kidney disease: HD: Haemodialysis, PD: Peritoneal Dialysis, CAPD: Continuous Ambulatory Peritoneal Dialysis, SC: Subcutaneous, IV: Intravenous, IP: Intra-peritoneal, Hb: Haemoglobin, EPO: Erythropoietin, rHuEPO: Recombinant Human Erythropoietin, ESRD: End-stage Renal Disease, rcEPO: Recombinant Human Erythropoietin, Cmax: Peak serum drug concentration, t1/2: drug half-life, S.D.: Standard Deviation