Here is the design of a clinical trial:

Official Title: Effectiveness of a Person-Centred Transition Program to Empower Adolescents With Type 1 Diabetes in the Transition to Adulthood: the STEPSTONES-DIAB Project

Included conditions:
- Type 1 Diabetes

Study Armgroups:
- {'label': 'Intervention group: transition program', 'type': 'EXPERIMENTAL', 'description': 'Participants come from two clinics and will be randomly allocated to this group. Participants will go through a transition program which will last for 2 years. The intervention will be performed by specialist nurses (transition coordinators) who meet the participants at three occasions during the study period and participants will be offered to meet peers with type 1 diabetes during an adolescent day.', 'interventionNames': ['Behavioral: A Person-Centred Transition Program to Empower Adolescents With Type 1 Diabetes in the Transition to Adulthood: the STEPSTONES-DIAB Project']}
- {'label': 'Comparison group: Standard care', 'type': 'EXPERIMENTAL', 'description': 'Participants allocated to this group will receive usual care, which includes regular follow-up visits in pediatric diabetes outpatient clinics. Usual care can vary across the two clinics, however, they all include meetings with a nurse and a physician.', 'interventionNames': ['Other: Standard care']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'A Person-Centred Transition Program to Empower Adolescents With Type 1 Diabetes in the Transition to Adulthood: the STEPSTONES-DIAB Project', 'description': 'Behavioral: Transition program Participants will be part of a transition program that aim to prepare them for adult life and adult care wich includes eight key components: 1. A transition coordinator; 2. Education on diabetes, treatments, health behavior, dealing with school, friends; 3. Telephone availability; 4. Information about the adult diabetes service: 5. Guidance of parents; 6. Meeting with peers: 7. A person-centered transition plan; and 8. Preparation and transfer to adult diabetes service.', 'armGroupLabels': ['Intervention group: transition program']}
- {'type': 'OTHER', 'name': 'Standard care', 'description': 'Participants allocated to this group will receive usual care, which includes regular follow-up visits in pediatric diabetes outpatient clinics. Usual care can vary across the two clinics, however, they all include meetings with a nurse and a physician.', 'armGroupLabels': ['Comparison group: Standard care']}

Primary Outcomes:
- {'measure': 'Level of empowerment', 'description': 'Gothenburg Young Persons Empowerment Scale (GYPES) will be used to assess the level of empowerment. This scale was developed by the researchers involved in this study and has been tested in a previous cross sectional study in order to determine its psychometric properties in adolescents with congenital heart disease and type 1 diabetes.The five subscales measure: (a) self-perceived level of understanding of their disease (knowledge and understanding); (b) the capacity patients have to handle their disease (personal control); (c) the effect their illness has on their lives and sense of self (identity); (d) the capacity to make decisions along with the healthcare professional (shared decision-making); and (e) the ability to share their experiences and help others who are going through a similar situation (enabling others). The total score ranges from 15 to 75 points, with a higher score reflecting a higher level of empowerment.', 'timeFrame': 'Endpoint after 2.5 years from baseline'}

Please estimate the sample size based on the assumption: 
Two-sided tests with alpha=0.05, power=80%, and a 10% dropout rate
Proposed sample size
        Based on the primary outcome, we target an improved patient empowerment score of 5.25 points on a scale from 15 to 75 (ie, 0.5 SD).29 For two-sided tests with alpha=0.05 and power=80%, 63 patients are needed in each arm of the RCT. In order to compensate for a potential 10% dropout rate, 70 patients will be included in each arm. Given that the two paediatric diabetes outpatient clinics together have about 100 patients in each age cohort of adolescents, and considering a 70% participation rate, a 24-month recruitment period is needed to enrol 140 patients in study arm 1 and 2.