Large knowledge gaps remain regarding strategies to promote the adoption of hydroxyurea (HU), particularly in sub-Saharan African countries including Nigeria, where more than 75% of annual sickle cell anemia births occur. The vast majority of people with SCD in Africa do not receive evidenced-based health care (e.g., newborn screening, health education, prophylaxis for infection, optimal nutrition and hydration, blood transfusion, transcranial Doppler screening, and HU therapy), despite its effectiveness in reducing SCD-related adverse outcomes and mortality. The use of HU in SSA is \<1% among SCD patients. The investigators' preliminary findings indicate that provider-level barriers are significant and must be addressed to improve HU adoption. To address HU adoption, the investigators will use the NIH-funded study (e.g., Realizing Effectiveness Across Continents with Hydroxyurea (REACH) Clinical Trial (NCT01966731)) that developed an evidence-informed, clinical, practical, and easy-to-follow algorithm to 1) Screen patients for sickle cell disease (SCD), 2) Initiate HU treatment, and 3) Maintain HU dosage over time (SIM) for the improved management of SCD as our intervention. The Nigerian government released guidelines supporting the SIM intervention for HU adoption for improved SCD management, and HU is on the list of essential medicines for Nigeria. The investigators' implementation strategy for improving SCD management in Nigeria uses a practical and replicable evidence-based task-sharing strategy, TAsk-Strengthening Strategy for Hemoglobinopathies (TASSH), adopted from the TAsk-Strengthening Strategy for Hypertension control (TASSH) trials in Ghana and Nigeria containing the essential components of i) Training healthcare workers/providers to be more patient-centered in clinical consultations, ii) Clinical reminders, and iii) Practice facilitation (TCP) known as (TASSH TCP) for SCD management. Using a sequential exploratory mixed-methods study design, the investigators will conduct this study using the Exploration, Preparation, Implementation, and Sustainment (EPIS) framework in four sequential phases to assess the effectiveness of SIM adoption by providers in the context of the TASSH TCP implementation strategy in Nigeria.