In the per-protocol analysis , the proportion of patients with an unfavorable response was 4.9 % in the control group , 3.2 % in the 6-month group ( adjusted difference from control , -1.8 percentage points ; 90 % confidence interval [ CI ] , -6.1 to 2.4 ) , and 18.2 % in the 4-month group ( adjusted difference from control , 13.6 percentage points ; 90 % CI , 8.1 to 19.1 ) .