The role of hydroxyurea in decreasing the occurrence of vasso-occulusive crisis in pediatric patients with sickle cell disease at King Saud Medical City in Riyadh, Saudi Arabia.

To measure the incidence of vaso-occlusive crises (VOC) and the role of hydroxyurea (HU) in reducing VOC in sickle cell anemia  patients being treated at a large tertiary care setting in Kingdom of Saudi Arabia (KSA). The secondary objective of this study is to observe the gradual improvement in laboratory data (white blood cell [WBC], platelets, mean corpuscular volume [MCV], hemoglobin [Hgb], HgbF) following regular use of HU. Methods: Clinical effectiveness of HU was evaluated in a large pediatric population using a retrospective cohort, non-interventional, pre-post treatment study designed to control disease severity selection bias.