This non-interventional, observational study investigates the efficacy, safety and usability of methoxy polyethylene glycol epoetin beta in participants on peritoneal dialysis. Participants who were prescribed methoxy polyethylene glycol epoetin beta by their doctor and who meet the selection criteria were to be enrolled and documented in this study for a period of 9 months of treatment with methoxy polyethylene glycol epoetin beta with respect to efficacy, safety and usability.