PelitAksu 2020.

Study characteristics
Methods	Study design: randomised controlled trial Study grouping: parallel group
Participants	Baseline characteristics Progressive muscle relaxation exercise (PMRE) Age (mean ± SD): 21.9 ± 0.84 Sex (N (% female)): NR (87%) Sample size: 100 Years of experience (mean ± SD): NA Control (no intervention) Age (mean ± SD): 22.07 ± 0.86 Sex (N (% female)): NR (83%) Sample size: 100 Years of experience (mean ± SD): NA Overall Age (mean ± SD): NR Sex (N (% female)): NR Sample size: 200 Years of experience (mean ± SD): NA Included criteria: sample inclusion criteria were as follows: Not having a disease that prevents students from doing PMR, such as metabolic diseases, cancer, heart disease, and diabetes, and not receiving antidepressant treatment, not doing any other mind–body exercises and using a smartphone Excluded criteria: NR Pretreatment: there were no statistically significant differences between the groups’ age and gender (P > 0.05) Compliance rate: 16 of the 100 less than 4 days (16%) Response rate: 100% Type of healthcare worker: exclusively student nurse interns
Interventions	Intervention characteristics Progressive muscle relaxation exercise (PMRE) Type of the intervention: Intervention type 2 ‐ to focus one’s attention away from the experience of stress Description of the intervention: Guided by verbal directions (The muscle relaxation CDproduced by the Turkish Psychologists Association), the students tensed and relaxed the muscle groups in hands, arms, neck, shoulder, chest, stomach, hips, foot and fingers, and all muscles in the face and body, in sequence. During the PMRE, the students listened to the audio instructions and applied the exercises exactly according to this audio instructions. In the meantime, the researcher observed the students and gave feedback by making the necessary corrections at the end of the exercise. The researcher did not interfere with the original version of the exercise. After the first session, the students were asked to perform the PMRE before sleeping, at least 4 days each week, every day if possible, for 3 weeks. At the end of the first session, a Whatsapp® group was created, and to follow‐up and motivate the students, they were asked to send a message to the group after each PMRE practice. The verbal direction was installed on the students’ smartphones, and the first meeting was concluded. The number of sessions: At least 4 days each week Duration of each session on average: 30 min Duration of the entire intervention: 3 weeks Duration of the entire intervention short vs long: Short Intervention deliverer: Experienced nurse with her PhD on progressive muscle relaxation technique Intervention form: Group Control (no intervention) Type of the intervention: NA Description of the intervention: After filling out the instruments during the first meeting in the classroom, the CG received no intervention. The number of sessions: NA Duration of each session on average: NA Duration of the entire intervention: NA Duration of the entire intervention short vs long: NA Intervention deliverer: NA Intervention form: NA
Outcomes	Burnout Measure Short Version Outcome type: ContinuousOutcome
Identification	Sponsorship source: This study did not receive any specific grant from funding agencies in the public, commercial, or not‐for‐profit sectors Country: Turkey Setting: Gynecology and obstetrics clinics Comments: NR Authors name: Sıdıka Pelit‐Aksu Institution: Department of Nursing, Faculty of HealthSciences, Gazi University, Ankara, Turkey Email: sidikapelit@hotmail.com Address: Sıdıka Pelit‐Aksu, MSN, RN, Department ofNursing, Faculty of Health Sciences, GaziUniversity, Emek mah. Bişkek Cad. 6. Cad.(eski 81. sokak) No:2 06490 Çankaya, Ankara, Turkey Time period: 2018–2019
Notes	Burnout Measure Short Version included in analysis 2.1.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "All of the students who met the inclusion criterias were grouped randomly using simple randomization method. Students names were selected from course attendance sheet of the internship and they were assigned simultaneously and sequentially to experimental group (EG = 100) and control group (CG = 100)." Sequence generation process insufficiently described
Allocation concealment (selection bias)	Low risk	Quote: "Students names were selected from course attendance sheet of the internship and they were assigned simultaneously and sequentially to experimental group (EG = 100) and control group (CG = 100)."
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants were not blinded.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Participants were not blinded whereas outcomes are self‐reported.
Incomplete outcome data (attrition bias) All outcomes	High risk	55 of the 200 randomised participants were lost to follow‐up (28%). Not mentioned whether loss to follow‐up was at random.
Selective reporting (reporting bias)	Unclear risk	No trial registration or no study protocol reported, nor did we find one online.
Other bias	Unclear risk	Quote: "and the information leakage from experimental groups to the control groups may have affected the results of the study."