Aim 3: Develop health care systems strategies to enhance medication adherence in adolescents and young adults: Medication adherence is determined by factors at a variety of different "levels": patient-level (patient-, condition-, and therapy-related factors), "micro"-level (social factors and interactions with the care team), "meso"-level (organization and expertise of the healthcare team and care processes), and "macro"-level (high-level healthcare systems factors, including care and medication cost coverage, and overall care environment). We hypothesize that there are significant differences in modifiable meso- and macro-level systems factors between pediatric programs, between adult programs, and between pediatric and adult programs. Furthermore, we hypothesize that modifiable meso- and macro-level systems factors are independently associated with medication adherence. This aim has two primary objectives: