Statistical analysis:
Descriptive statistics were used to compare demographic and clinical characteristics between individuals with SCD younger than 12 years and those 12 to 21 years of age with VTE. The age at the time of index VTE was used as a binary variable to compare the clinical characteristics between the two groups based on the known change in VTE rate after puberty.8 Fisher’s exact test was used to compare categorical variables because of the small sample size in any given cell of the contingency table. A two-sided p-value of 0.05 was used for statistical significance.