Hydroxyurea Adherence for Personal Best in Sickle Cell Disease (HABIT): Efficacy Trial

Hydroxyurea Adherence for Personal Best in Sickle Cell Disease (HABIT): Efficacy Trial

Many youth with chronic disease have difficulty taking medication every day and therefore do not receive full benefit from treatment. Sickle Cell Disease (SCD) is an inherited blood disease that affects African Americans and other underserved communities. Hydroxyurea (HU) is the sole FDA-approved drug therapy for SCD and is highly effective and improves quality of life. The proposed study, a 5-site four-year randomized control trial (RCT), builds upon the investigators' recent feasibility study of the same title. Overall goals are reducing barriers to HU use and improving adherence for youth 10-18 years through creation of a daily medication habit. The goal of the proposed multi-site study is to test the efficacy of the HABIT intervention at 6 months and sustainability of the effect at 12 months.

Barriers to medication adherence are common in youth with chronic illness and are a source of racial/ethnic disparities in underserved communities. An inherited blood disease, Sickle Cell Disease (SCD) is characterized by chronic and acute illness and reduced quality of life (QOL). It affects African Americans and other underserved communities. Hydroxyurea (HU) is the sole FDA-approved drug therapy for SCD and is highly effective and improves QOL. Poor adherence is common among youth and young adults with SCD.

The importance of poor medication adherence, use of community-based health workers (CHWs) to bridge the gap between health services and underserved parent-youth dyads affected by SCD, the strength of the science, the success of the investigators' multi-ethnic feasibility study, and the potential application of study findings to youth with other serious chronic illnesses speak to the importance of this trial.

Inclusion Criteria - Youth:

• One of the two most common sickle cell disease variants (HbSS or HbS-B0 thalassemia)
• Age 10 through18 years (inclusive)
• Currently prescribed hydroxyurea (HU) ≥18 months (for identifying historical Personal best HbF)
• Current HU dose is within 5% of dose at Personal Best HbF
• Pre-enrollment HbF ≥15% below historical Personal best, based on mean of ≥2 HbF assessments over preceding 12 months
• Youth able to speak/read English or Spanish

Inclusion Criteria - Parent:

• Parent/guardian speaks/reads English or Spanish
• Parent/ legal guardian willing to participate
• Family expects to reside in community for ≥ 1.5 years

Exclusion Criteria - Youth:

• Youth not prescribed HU
• <2 HbF assessments over past 12 months
• Transfusion within 3 months preceding enrollment
• Final screen HbF (visit 0) of ≤15% decrease below Personal best HbF
• Sexually active female 10 years or older and not using reliable contraception (due to HU teratogenic risk)
• Pregnancy
• Cognitive impairment (>2 levels below expected grade)
• Youth not residing with parent/legal guardian

Exclusion Criteria - Parent:

• Parent/legal guardian does not reside with youth