By multiple imputation , the NIS +7 score increased by 25.0 ( 95 % CI , 18.4-31 .6 ) points in the placebo group and by 8.7 ( 95 % CI , 3.3-14 .1 ) points in the diflunisal group , a difference of 16.3 points ( 95 % CI , 8.1-24 .5 points ; P < .001 ) .