Ozbas 2016.

Study characteristics
Methods	Study design: randomised controlled trial Study grouping: parallel group
Participants	Baseline characteristics Psychological empowerment program Age in years (category (N (%))): 18‐27 (11 (29%)) ‐ 28‐37 (22 (58%)) ‐ 38+ (5 (13%)) Sex (N (% female)): NR Sample size: 38 Years of experience (category (N (%))): 0‐5n(12n(32%)) ‐ 6‐10 (14 (37%)) ‐ 11+(12 (32%)) Control (no intervention) Age in years (category (N (%))): 18‐27 (21 (48%)) ‐ 28‐37 (23 (52%)) ‐ 38+ (0 (0%)) Sex (N (% female)): NR Sample size: 44 Years of experience (category (N (%))): 0‐5 (28 (64%)) ‐ 6‐10 (11 (25%)) ‐ 11+ (5 (11%)) Overall Age in years (category (N (%))): 18‐27 (32 (40%)) ‐ 28‐37 (45 (55%)) ‐ 38+ (5 (6%)) Sex (N (% female)): NR Sample size: 82 Years of experience (category (N (%))): 0‐5 (40 (49%)) ‐ 6‐10 (25 (31%)) ‐ 11+ (17 (21%)) Included criteria: scored less than 17 on the Beck Depression Inventory and did not have any diagnosed physical or mental disease. Excluded criteria: NR Pretreatment: NR Type of healthcare worker: exclusively nurses Response rate: 86% Compliance rate: 83%
Interventions	Intervention characteristics Psychological empowerment program Type of the intervention: Intervention type 4 ‐ Combination of two or more of the above Description of the intervention: In every session, participants were given a module related to a particular scenario and asked to act it out extemporaneously. After every session, participant feedback was offered, and their awareness about the style of discussing the theme by themselves and with other group members, communication patterns and emotions, ideas and behaviours were registered. Program sessions included a time for getting acquainted and for an introduction to the program. Discussions about the group contract, coping with stress, and cognitive distortion were held. Relaxation techniques were also taught, along with problem‐solving, self‐recognition, empathy, and dispute resolution The number of sessions: 10 Duration of each session on average: 2 hours Duration of the entire intervention: 10 weeks Duration of the entire intervention short vs long: short Intervention deliverer: The first author, who conducted all the psychodrama intervention sessions and is a certified psychodramatist Intervention form: Group Control (no intervention) Type of the intervention: NA Description of the intervention: NA 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	Maslach Burnout Inventory ‐ Emotional exhaustion Outcome type: ContinuousOutcome Maslach Burnout Inventory ‐ Desensitization Outcome type: ContinuousOutcome Maslach Burnout Inventory ‐ Personal achievement Outcome type: ContinuousOutcome
Identification	Sponsorship source: NR Country: Turkey Setting: Adult inpatient oncology clinics Comments: NR Authors name: Azize AtliO ¨zbas Institution: Hacettepe University Nursing Faculty, Psychiatric Nursing Department, Hacettepe Universitesi Hems ¸irelik Faku ¨ ltesi Email: azeozbas@gmail.com Address: 06100 Sıhhiye, Ankara, Turkey. Time period: NR
Notes	MBI‐EE included in analysis 4.1
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Using a computerized black‐box randomization assignment program,"
Allocation concealment (selection bias)	Unclear risk	Insufficient information to understand whether intervention allocations could have been foreseen in advance of, during, enrolment.
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	Low risk	Quote: "Some 8 nurses dropped out of the intervention group and 1 dropped of the control group," Nine of 82 randomised (11%) nurses were lost to follow‐up. This is below our pre‐defined cut‐off value.
Selective reporting (reporting bias)	Unclear risk	No trial registration, nor did we find one online.
Other bias	Low risk	No indication of other bias.