A 2-fold increase in MIC was associated with a larger 3-month infiltrate or scar size ( 0.21 mm ; 95 % confidence interval [ CI ] , 0.10-0 .31 ; P < 0.001 ) and increased odds of perforation ( odds ratio , 1.32 ; 95 % CI , 1.04-1 .69 ; P = 0.02 ) .