Study population
We included patients less than 21 years of age with any sickle cell
genotype (HbSS, HbSC, and HbSβThal0/+) and a VTE event
during hospitalization (deep vein thrombosis [DVT], cerebral sinus
venous thrombosis [CSVT], and pulmonary embolism [PE]). We
excluded patients with sickle cell trait, arterial thrombosis, and/or
acute stroke. These patients were identified using ICD9 and ICD10 codes
for SCD, DVT, CSVT, and PE. Patient charts were then manually reviewed
for confirmation of SCD diagnosis and presence of hospital-acquired VTE
on imaging. We defined hospital-acquired VTE as any VTE occurring at
least 48 hours after admission, or within 1 week after discharge,
consistent with the guidelines from the Solutions for Patient
Safety.13