The frequency of grade 3 or 4 haematological events decreased from 82 % ( n = 135 ) to 70 % ( n = 92 ) and grade 3 or 4 non-haematological events from 78 % ( n = 128 ) to 59 % ( n = 77 ) in the carboplatin arm when the dose of carboplatin was reduced from AUC 20 to 15 .