Significant prognostic factors were identified as thyroid-stimulating antibody ( by 100 % linear increase : risk ratio , 1.15 ; 95 % confidence interval , 1.07-1 .24 ; P = .0003 ) and clinical activity score ( 1 vs 0 : risk ratio , 6.40 ; 95 % confidence interval , 2.17-19 .7 ; P = .0009 ) .