Mao 2021.

Study characteristics
Methods	Study design: randomised controlled trial Study grouping: parallel group
Participants	Baseline characteristics Emotional intelligence training Age in years (mean ± SD): 30.6 ± 5.0 Sex (N (% female)): NR Sample size: 53 Years of experience (mean ± SD): 9.3 ± 6.0 Control (daily training) Age in years (mean ± SD): 31.3 ± 6.6 Sex (N (% female)): NR Sample size: 50 Years of experience (mean ± SD): 9.7 ± 7.2 Overall Age in years (mean ± SD): 30.9 ± 5.8 Sex (N (% female)): NR Sample size: 103 Years of experience (mean ± SD): 9.5 ± 6.6 Included criteria: the inclusion criterion was the possession of Chinese nurses' practice qualification certificates. Excluded criteria: the exclusion criteria were as follows: (a) suffering from serious physical or mental illness; (b) taking psychotropic drugs; (c) nursing staff who took maternity leave, sick leave, retirement, or further study in the study period; (d) had participated in systematic EI training before; and (e) had worked in a psychiatric ward. If participants in the intervention group were absent twice, they were excluded from the study. Pretreatment: there were no statistically significant differences in demographic characteristics between the two groups at baseline. Type of healthcare worker: exclusively nurses Response rate: 76% Compliance rate: 81%
Interventions	Intervention characteristics Emotional intelligence training Type of the intervention: Intervention type 1 ‐ to focus one’s attention on the experience of stress Description of the intervention: In the system training phase, educators explained emotional intelligence to the intervention group through class lectures. Lectures covered themes such as perception of emotions, awareness of emotions, regulation of emotions and practice. // Phase II was the consolidated learning phase. The process of each case discussion was as follows: (a) Preparation, (b) Case description, (c) Case confirmation, (d) Case discussion, (e) Case summary The number of sessions: 48 Duration of each session on average: 60 to 90 minutes Duration of the entire intervention: 48 weeks Duration of the entire intervention short vs long: long Intervention deliverer: four educators with a National Counsellor Level 2 or higher certification, a master's degree, and 10 years of clinical psychology teaching experience to deliver the EI intervention to the nurses Intervention form: Class lectures, case discussions Control (received daily briefings in meetings between head nurses, which were held regularly to discuss specific problems. There was no emotional intelligence training conducted with the control group.) 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	Perceived Stress Scale (PSS) Outcome type: ContinuousOutcome
Identification	Sponsorship source: This study was supported by the Nursing Research Project of The Second Xiangya Hospital, Central South University (2017‐YHL‐15). Country: China Setting: NR Comments: NR Authors name: LingZhi Huang, QiongNi Chen Institution: The Second Xiangya Hospital, Central South University Email: huanglingzhi@csu.edu.cn, chenqiongni@csu.edu.cn Address: 139 Renmin Middle Road, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China. Time period: January 2019 ‐ January 2020
Notes	PSS included in analysis 1.1
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Ten wards were randomly assigned to the intervention group and ten to the control group."
Allocation concealment (selection bias)	Unclear risk	Difficult to judge whether participants and/or investigators could possibly foresee assignment.
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: "Overall, the intervention and control groups lost 10 and 5 participants, respectively." 15 of the 103 randomised participants lost to follow‐up, which 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.