The study, known as mAnaging siCkle CELl disEase Through incReased AdopTion of hydroxyurEa in Nigeria, aims to encourage the use of a medicine called hydroxyurea (HU) for treating sickle cell disease (SCD) in Nigeria. Sickle cell disease is a condition where red blood cells, which carry oxygen in the body, become sickle-shaped and can block blood flow. Hydroxyurea helps reduce the problems caused by SCD. In Nigeria, not many patients use this helpful medicine. The study involves teaching healthcare workers to better manage SCD using HU through a strategy called TASSH, which includes training, reminders, and practice facilitation. The study will be conducted in four phases over 24 months, assessing healthcare workers' adoption of HU treatment. Participants include SCD patients who are 18 years or older or pediatric patients (12 months to 17 years) with consent.

• Study lasts up to 24 months with several phases.
• Participants include SCD patients not currently on HU.
• Healthcare workers will receive training to improve SCD management.