A, Mandatory ventilation: Among 502 patients undergoing Norwood palliation, 463 (92%) achieved a freedom‐from‐mandatory‐ventilation within the first 28 postoperative days, in a median time of 8 days (IQR, 5–13). Overall comparison of distribution by log‐rank test showed a significant difference among centers (P<0.001). Pairwise comparisons by log‐rank test using Bonferroni correction are shown in Table S2 and showed that Center 1 differs significantly from Centers 3, 4, and 5, and Center 4 differs significantly from all other centers (all P<0.001). B, Opioid administration: 411 patients (82%) achieved a freedom‐from‐opioid‐administration within the first 28 postoperative days, in a median time of 11 days (IQR, 7–18). Overall comparison of distribution by log‐rank test showed a significant difference among centers (P<0.001). Pairwise comparisons by log‐rank test using Bonferroni correction are shown in Table S2 and showed that Center 4 differs significantly from all other centers (all P<0.001). IQR indicates interquartile range; and MMVR, mandatory mechanical ventilator rate.