3. Sample Size and Technique One hundred and ten patients were planned to be recruited in each arm according to number of eligible subjects after screening period. (Alpha= 0.05, B= 0.20 having 66% response rate by MIRCERA , 40.4% response rate by darbepoetin alpha So by comparing the sample size happened to be 107 individual for each group.[Statistical methods for rates and proportion by Joseph L. Fleiss (2nd. 1981, John Wiley & Sons, NY), chapter 3].