Hydroxycarbamide versus chronic transfusion for maintenance of transcranial doppler flow velocities in children with sickle cell anaemia-TCD With Transfusions Changing to Hydroxyurea (TWiTCH): a multicentre, open-label, phase 3, non-inferiority trial. - Ware RE; Davis BR; Schultz WH; Brown RC; Aygun B; Sarnaik S; Odame I; Fuh B; George A; Owen W; Luchtman-Jones L; Rogers ZR; et al. (Lancet (London, England), 2016)