Tranexamic Acid N = 70 No Tranexamic Acid N = 160 P Value Age (years) 14.8 (2.6) 14.8 (2) 0.81 Gender (Female) 53 (76%) 125 (78%) 0.82 Weight (kg) 56.5 (49, 68) 55.1 (46, 63) 0.04 Levels Fused 10 (8, 12) 10 (9, 11) 0.22 Surgeon A 43 (61%) 88 (55%) 0.45 Surgical Time (min) 237 (198, 270) 230 (203, 269) 0.66

Table 1: Demographics Data (normally distributed) is presented as mean (standard deviation) and is analyzed by Students t-test. Data (not normally distributed) is presented as median (interquartile range) and is analyzed by Wilcoxon Rank Sum test. Categorical data is presented as number and percentage of group and is analyzed by Pearson chisquared test with Yates continuity correction.