This study was designed as a randomized controlled experimental study to examine the effects of peer-interaction group support in adolescents with celiac disease (CD) in the 13-18 age group on the quality of life, friendship relations, and coping levels of adolescents.

Six peer interactive group sessions were held with one week intervals with adolescents (n = 18) in the study group included in the sample for a period of 3 months. In the sessions, all participants were asked questions about the purpose of the session and a discussion environment was created. No training and counseling were provided to the adolescents in the control group (n = 18). Before and after the peer interactive group support, adolescents in the intervention and control group were asked to complete the quality of life, friendship qualities, and coping scales.

The study is a randomized controlled experimental study conducted to examine the effect of peer interactive group support on quality of life, peer relationships and coping (coping) levels in adolescents aged 13-18 years with celiac disease.

The study was conducted on adolescents with a diagnosis of celiac disease in the outpatient clinic of the Department of Child Health of Afyon Kocatepe University in Afyonkarahisar. This change took place after research permissions were obtained. Patients are served in the polyclinic between 09:00 and 17:00 on weekdays. Gastroenterology Specialist, who monitors the patients with Celiac diagnosis, works as a physician. There are no nurses in the polyclinic and individual training is not given to celiac patients according to their needs.

There are 85 patients with a diagnosis of celiac disease in the 0-18 age group who were followed up in the Department of Child Health and Diseases of Afyonkarahisar Health Sciences University, where the study will be conducted. It was determined from the patient records that there were 36 patients with a diagnosis of celiac disease in the 13-18 age group. The universe of the study consisted of patients with a diagnosis of celiac disease in the 13-18 age group who were followed up in the Pediatric Outpatient Clinic of Afyonkarahisar University of Health Sciences.

Data Collection Tools Introductory Information Form, Quality of Life Scale for Children (13-18 age group), Friendship Qualities Scale and Coping Scale for Adolescents prepared by the researcher for data collection.

Introductory Information Form In this form prepared by the researcher, there are 14 questions regarding the demographic characteristics of the mother, father, family and child. After randomization, an introductory information form (before peer interactive group support) was administered to all adolescents in the research and control groups in a classroom of the Pediatric Outpatient Clinic where the study was conducted.

Children's Quality of Life Scale - PedsQL (13-18 age group) The quality of life scale for children was developed by Varni et al. (1999) to measure the quality of life of children and adolescents aged 2-18 years. The internal consistency coefficient (Cronbach's alpha) of the section prepared for children of the scale developed by Varni et al. Was found to be 0.93. Memik et al. (2007) conducted a study on the validity and reliability of the adolescent form of the PedsQL (13-18 years old).

While the World Health Organization defines health, it covers the areas of physical, emotional and social functionality. Scoring is made for these three areas in the scale. In the scale, a fourth area under the name of school functionality is questioned. The psychosocial health total score (PSTP) is calculated by calculating the total score (STP), physical health total score (FSTP), emotional, social and school functionality item scores in the scale.

The Quality of Life Scale for Children (PedsQL) is a scale suitable for use in healthy or ill children and adolescents in settings such as schools and hospitals. The scale consists of 23 items in total. The scale is in the form of a 5-point Likert scale and is scored between 0-4. The items are scored between 0-100. The scale gives 100 points for never answer, rarely 75 points for its answer, sometimes 50 points for its answer, often 25 points for its answer, and almost always 0 points for its answer. The Turkish validity and reliability study of the PedsQL for the 13-18 age group was conducted by Memik et al. (2007). The internal consistency coefficient (Cronbach's alpha) of the form prepared for adolescents in the study of Memik et al. Was found to be 0.82.

Friendship Qualities Scale The friendship qualities scale aims to evaluate the relationships of 10-18 year old children and adolescents with their best friends. The scale was created by Bukowski et al. (1994). The internal consistency coefficients (Cronbach's alpha) according to the sub-dimensions of the scale were: 0.72; conflict: 0.68; proximity: 0.76; help: 0.81; and protection: found to be 0.58. The Turkish validity and reliability study of the scale was conducted by Erkan Atik et al. (2014). Participants included in the study are secondary and high school students. The internal consistency coefficient of the whole scale in the study of Erkan Atik et al. Was found to be 0.85. The scale includes 22 items and five sub-dimensions. The scale is graded from 1 to 5. "1" is not right for your friendship, "2" may be correct, "3" is usually correct, "4" is very correct, "5" is completely correct. The sub-dimensions of the scale are togetherness, conflict, assistance, protection and closeness. Togetherness sub-dimension, items 1, 2, 3 and 4, conflict sub-dimension 5,6,7 and 8 items, help sub-dimension 9,10,11,12 and 13 items, protection sub-dimension 14,15,16 and 17th items, proximity sub-dimension is calculated by evaluating items 18,19,20,21 and 22. All items in the conflict sub-dimension of the scale are calculated by reverse coding. The scores that can be obtained vary between 4-20 in the Togetherness, Conflict and Protection sub-dimensions, and 5-25 in the Assistance and Proximity sub-dimensions. If the scale score to be obtained from both the total score and the sub-dimensions is high, this is considered as positive peer relationships.

Coping Scale for Adolescents (KIDCOPE) The scale, which was created by Spirito et al. (1988) under the name of KIDCOPE (multidimensional coping strategies for children scale), consists of two forms for children (5-13 years old) and adolescents (13-18 years). The internal consistency coefficient (Cronbach's alpha) of the scale was 0.62. The Coping Scale for Adolescents consists of 11 items in total. This scale includes ten coping strategies. These strategies include social distancing, distraction, desiring thinking, problem solving, withdrawal, cognitive restructuring, social support, emotion regulation, self-criticism, and blaming others.

The 10 strategies included in KIDCOPE are; distraction (played a game to watch or forget TV), withdrawal (left alone), desiresing thinking (wanted to be able to do things differently), self-criticism (blamed myself), blaming others (blaming someone else for causing the problem), problem solving (I tried to solve the problem by thinking about the answers), emotion regulation (tried to calm myself or yelled, screamed), cognitive restructuring (tried to see the good side of things), social support (tried to feel better by spending time with family or friends) and social distancing (I didn't want to spend time with my family or friends) The 10 strategies included in KIDCOPE are; distraction (played a game to watch or forget TV), withdrawal (left alone), desiresing thinking (wanted to be able to do things differently), self-criticism (blamed myself), blaming others (blaming someone else for causing the problem), problem solving (I tried to solve the problem by thinking about the answers), emotion regulation (tried to calm myself or yelled, screamed), cognitive restructuring (tried to see the good side of things), social support (tried to feel better by spending time with family or friends) and social distancing (I didn't want to spend time with my family or friends) In the implementation phase of the study, a classroom belonging to the Child Health and Diseases Polyclinic of Afyonkarahisar Health Sciences University Faculty of Medicine Hospital was used. All sessions in the research were held in this classroom. The sessions lasted an average of 90 minutes in two 45-minute sections. Gluten-free products were presented during the 20-minute break between sessions. During the break, adolescents were given the opportunity to interact with each other by chatting. The pre-test application of the introductory information form and scale forms of all the participants in the research group was applied at the beginning of the first session, and the post-test application at the end of the last session, which was the sixth session. The pre-test application of the participants included in the control group was applied on the same day separately from the research group, and the post-test application (only scales) was applied in the same classroom at the end of all sessions.

Research Group Interactive peer group support was implemented for 3 months, one week apart. A total of 6 sessions were held with the research group. Group meetings were planned to be held at the weekend in order to prevent adolescents' attendance at school. However, as the data collection phase is in the summer and schools are closed, the sessions were held on weekdays and bi-weekly. The adolescents in the study group were reached by phone before each session. One day before the session, all participants were sent a text message informing the meeting and its place and time and they were invited. Each session lasted 1.5 hours on average.

The contents of the first and second sessions of the research were prepared beforehand. However, the contents of the third, fourth, fifth and sixth sessions were arranged after the first two sessions. Table of contents of the 6 sessions held is presented in Table 3.

In the sessions, all participants were asked questions regarding the target determined for the session. By creating a discussion environment based on these questions, it was ensured that the participants shared their problems and solutions with each other. The responses of the participants to the questions were noted and reported by the researcher.

Control Group No peer interactive group support was provided to the control group. In the control group, in a classroom belonging to the University's Child Health and Diseases Polyclinic where the study was conducted, the Introductory Information Form, the Quality of Life Scale for Children, the Friendship Qualities Scale, the Adolescent Coping Scale were applied after the adolescents and parents were informed about the subject of the study and written permission was obtained. Three months later, the Adolescents in the control group were administered the Quality of Life Scale for Children, Friendship Qualities Scalee, and the Adolescent Coping Scale.

The adolescents in the control group were not informed about the routine education they received from the hospital during the study. A separate training meeting was held for the control group on 11.10.2018, after all sessions of the peer interactive group support of the study were completed. The training lasted about one hour in the classroom of the University's Child Health and Diseases Polyclinic. The definition, symptoms and signs of celiac disease, treatment and dietary rules were discussed in the training content. At the end of the meeting, an information booklet titled "Living with Celiacs" was given.

Inclusion Criteria:

• Must have had celiac disease for more than a year
• Must be between 13-18 years old

Exclusion Criteria:

• Another chronic disease
• Psychiatric illness