The goal of this interventional quasiexperimental study is to learn about the influence of therapeutic education carried out by nurses in the management and knowledge of patients with T1DM. Participants will be:

Given several therapeutic education sessions. Evaluated using different questionnaires and anthropometric measures.

The main objective of the study will be to determine the influence of therapeutic education carried out by nurses in the management and knowledge of patients with T1DM who will make a hospital transition. The research design will be a single-blind, nonrandomized, quasi-experimental, single-center, 1-group controlled study .

It will be developed at the Center for Diagnosis and Treatment (CDT) of the Virgen del Rocío University Hospital (HUVR), in Seville (Spain). The participant selection process will be carried out considering that only 13 adolescents 17 and 18 years and younger with T1DM, belonging to the reference hospital area, will transit from the Children's Hospital to the Adult Hospital. It is estimated that the study will have a sample of a minimum of n=10, which will be studied over 12 months.

Given the existing bibliography about the benefits of this intervention , 1 it is expected that the glycosylated hemoglobin (HbA1c) of patients will be less than 7%, which together with the Self-Management Adherence Questionnaire for Diabetes Treatment (SCI-R. es) 2 represents that patients perform adequate management of their disease. The Survey of Eating Problems in Diabetes Summary Questionnaire (EPAD-R) 3 will be used to assess their eating behavior. An improvement in people's knowledge regarding hypoglycemia is also sought, measured with the Clarke test 4 ; and an improvement in the quality of life, measured with the SF-12 questionnaire 5 and family support with the Apgar test 6 .

The therapeutic plan consists of preparing the process prior to discharge from the pediatric center, transferring to the adult hospital with a clinical and educational report and a previously arranged visit to the new unit. The heads of both teams coordinate the structure and the transition process with regular meetings. From the Adult Diabetes Day Hospital, a joint visit is reserved with the endocrinologist and the nurse educator. They are integrated into a 12-month therapeutic care and education program. It consists of four structured phases: 1. Welcome nurse visit, 2. Diabetologic education course adapted to the detected needs, 3. Individualized follow-up through alternating quarterly appointments between nurses and endocrine physician, 4. Evaluation and discharge of the program.

At the beginning (baseline visit), at 3 and 12 months the following variables are recorded:

1. Age (years), sex (female/male), T1DM evolution (years).
2. Treatment type (basal-bolus/insulin pump). Sensor usage time (>80%)
3. Metabolic control: HbA1C (mg/ dL ), Time in Range (TIR), Time Above Range (TAR), Time Below Range (TBR), Coefficient of Variation (CV), Mean Glucose (GMI), weight (Kg), height (cm), BMI (Kg/m 2 ).
4. Perception of quality of life. Test SF-12, of 12 questions.
5. Perception of symptoms of hypoglycemia. Clarke test, 8 questions.
6. Eating behavior, with the EPAD-R test, of 16 questions.
7. Adherence to diabetes treatment. SCI-R.es test. The results analysis plan will be carried out using Microsoft Excel, SPSS or R Commander computer programs , in which the relationships between the descriptive statistics extracted from the screened data will be explored to prevent duplicates. The same digital tools will be used to guarantee the protection of the data and variables collected. This aspect is detailed in the attached informed consent.

Regarding the ethical and legal aspects of the study, it is worth mentioning the benefit in disease management, quality of life and general satisfaction that the protocolized follow-up will cause in adolescents. No risk to the psychosocial integrity of the population involved in the study has been detected.

The necessary facilities will be the Education Classroom of the HUVR Diabetes Day Hospital, computer support through 2 computers, paper resources for the questionnaires, 2 nurses and 1 endocrinologist will be necessary as human resources. The authors declare the absence of funding or conflict of interest for the development of the research.

Inclusion Criteria:

• Age 17 years.

Exclusion Criteria:

• Unable to give informed consent.