Patients receiving combination therapy were more likely to have a haemoglobin level of < 8.5 g/dL ( 70 % vs. 8 % , risk difference ( RD ) : 62 % [ 95 % CI 50 % to 73 % ] ; p < 0.001 ) and required a higher dosage [ mean : 13,417 vs. 6667 IU/week , p = 0.027 ] of epoetin to manage anaemia than those receiving monotherapy .