HU is an FDA approved medication for the treatment of SCD. Many studies have shown that HU can reduce SCD related symptoms, but only 50% of patients take it as often as they should. This limits how much HU can help reduce SCD symptoms.

Researchers are interested to see if electronic directly observed therapy (Mobile DOT), a program that uses cell phone reminder messages, videos, feedback messages, and incentives will help patients with SCD take HU as prescribed.

This is a 12-month, single-arm, cross-over study for pediatric and adolescent patients with SCD who are prescribed HU at Nationwide Children's Hospital in order to compare HU adherence prior to the study, during Mobile Dot use and after using Mobile DOT.

Hydroxyurea (HU) is the only disease-modifying medication for patients with sickle cell disease (SCD). Multiple clinical trials show that HU can reduce SCD-related complications but only 50% of pediatric patients adhere to HU at the rates achieved in clinical trials. This poor adherence limits its clinical effectiveness and results in increased costs and in lower patient-reported quality of life.

An innovative, practical, inexpensive, and efficient strategy is needed to improve HU adherence in pediatric patients with SCD. Electronic directly observed therapy (Mobile DOT) is a pilot-tested, multi-dimensional tool that is a feasible and acceptable strategy and can achieve >90% HU adherence rates in a small cohort of pediatric patients with SCD. This study will provide further testing to confirm if Mobile DOT can improve adherence and improve clinical outcomes in patients with SCD.

Mobile DOT uses patients' smart phones and computers to provide electronic reminder alerts and to video-record patients' daily HU administrations. Patients are provided with text (SMS) messages, e-mails, and phone call communications to encourage adherence and they receive monetary incentives when they reach adherence goals.

Researchers will determine if video adherence correlates with self-report, biomarker, and refill adherence. Also, surveys will be completed by participants to determine if their self-management skills improve with Mobile DOT.

Inclusion Criteria:

• Diagnosis of Sickle Cell Disease (SCD), any genotype
• Prescribed HU for at least the previous 6 months
• Plans to receive SCD-related care at Nationwide Children's Hospital for the study duration
• For participants ≥18 years: participant must have access to a smart-phone or computer capable of recording and submitting videos to Mobile DOT
• For participants <18 years: consenting adult must have access to a smart-phone or computer capable of recording and submitting videos to Mobile DOT AND agrees to enter into a mutual agreement to participate in the daily medication administration routine
• Patient and/or consenting adult must speak English
• Access to a working phone (smart phone or landline)

Exclusion Criteria:

• Current chronic transfusion therapy or apheresis