The investigators will explore barriers to improving self-efficacy, or the ability to feel in control of their disease, and medication adherence with text messaging through surveys and interviews with adolescents and adults with SCD cared for at the Vanderbilt Meharry Center of Excellence (VMCE) in Sickle Cell Disease (SCD). The investigators will identify preferences to improve and sustain adherence to daily medication through selection of investigator-proposed or patient-generated text messaging strategies. Finally, the investigators will fill in the literature gaps by describing barriers to self-efficacy and medication adherence among adults with SCD as well as adolescents with SCD who are transitioning to adult care.

Inclusion Criteria:

1. Receiving care at the VUMC/Matthew Walker clinic
2. Diagnosed with SCD, asthma, or both
3. Currently taking daily medications for SCD, such as hydroxyurea, asthma, or both
4. Having access to a mobile telephone and/or computer
5. Age 12-70 years

Exclusion Criteria:

1. Unable to perform interviews or surveys

The investigators will assess barriers to self-efficacy and medication adherence in the adolescents and adults with sickle cell disease (SCD), asthma, or both, who take daily medications such as hydroxyurea, asthma, or both, have access to mobile phones and/or computers and receive care at the VUMC/Matthew Walker clinic.