A non-interventional study to assess the hemoglobin level depending on the comorbidity index in chronic kidney disease (CKD) patients not on dialysis treated with Mircera®

Primary objective : Describe in current medical practice the evolution of hemoglobin levels during the 9-month follow-up in each subgroup defined by the Charlson comorbidity index. Secondary objectives : - Describe the characteristics of patients treated with Mircera® in the total population and in the subgroups defined by the Charlson comorbidity index; - Describe the evolution of the hemoglobin level during the observation period according to the Liu comorbidity index and to ESA resistance factors; - Describe the changes in the Mircera® dosage during the observation period in the total population and in the subgroups defined by the Charlson comorbidity index; - Describe the safety profile of Mircera® during the observation period in the total population and in the subgroups defined by the Charlson comorbidity index.