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.