Efficacy of Hydroxyurea in Observational Studies of Children With SCD

OutcomeStudies, nMagnitude and Consistency of EffectEvidence Grade
HbF%1793%–366% increaseHigh
Hemoglobin165%–20% increaseHigh
Pain crises5Significant reductions in 3, no difference in 1, no baseline data in 1Moderate
Hospitalization556%–87% decline in yearly rateHigh
Transfusions3Decreased in 3 small studiesInsufficient
Neurologic events3Comparable stroke rates as on chronic transfusion, stable brain imagesLow
Splenic function3Improved in 14%–45% of children by scintigraphy; no change in pitted red cells in 1 studyLow