Ireland 2017.

Study characteristics
Methods	Study design: RCT Study grouping: parallel group Unit of randomisation: individuals Power (power & sample size calculation, level of power achieved): not specified; sample size was a weakness of the current study and possibly precluded several simple effects from reaching conventional levels of significance Imputation of missing data: not applicable since there were no withdrawals or exclusions
Participants	Country: Australia Setting: medical interns from large hospital ED; exact training setting not specified Age: mean = 26.88 (SD = 4.79, range = 22 ‐ 48) years Sample size (randomised): 44 Sex: 28 women, 16 men Comorbidity (mean (SD) of respective measures in indicated, if available) at baseline: burnout (CBI): IG = 2.55 (0.52), CG = 2.65 (0.75) Population description: intern doctors completing their practicum rotation in the ED of a major metropolitan hospital Included criteria: not specified Excluded criteria: not specified Attrition (withdrawals and exclusions): information received from authors (Ireland 2019 [pers comm]): no withdrawals or exclusions; all participants stayed in the trial for the full length of time Reasons for missing data: not applicable since there were no withdrawals or exclusions
Interventions	Intervention: Mindfulness training programme (for participants named as "resiliency and mindfulness program") (n = 23) delivery: face‐to‐face; training workshops, probably group setting providers: not specified duration of treatment period and timing: 10 weekly 1‐hour sessions description: mix mindfulness education and practice; adapted from well‐validated psychological treatment programmes (MBSR, MBCT, and ACT); adaptations necessary to make material applicable for non‐clinical population 10 SESSIONS: (1) introducing mindfulness, (2) everyday awareness and automatic pilot, (3) barriers to being mindful, (4) mindfulness of breathing theory and activities, (5) staying present at work and daily life, (6) letting go of sensations and emotions, (7) the nature of thoughts, (8) self‐care, (9) applying what has been taught, and (10) review Each session covered theoretical content of other intervention programmes (MBSR; MBCT, ACT) and, when time permitted, included common mindfulness exercises (mindfulness of breathing, mindfulness of the body, mindfulness of eating, etc.) participants encouraged to practise regularly outside the sessions compliance: not specified integrity of delivery: not specified economic information: not specified theoretical basis: adapted from well‐validated psychological treatment programmes (MBSR, MBCT, ACT) Control: active control (n = 21) duration of treatment period and timing: 1 hour a week for 10 weeks description: extra hour break time in the middle of the day compliance: not specified
Outcomes	Outcomes collected and reported: perceived stress ‐ PSS burnout ‐ CBI Time points measured and reported: 1) pre‐intervention; 2) during intervention (week 5 of 10‐week intervention); 3) post‐intervention (in final session, i.e. week 10) Adverse events: not specified
Notes	Contact with authors: We contacted the authors to get the information about possible withdrawals/exclusions in the 2 groups and the number of participants analysed in each group (Ireland 2019 [pers comm]). Study start/end date: not specified Funding source: not specified Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article. Ethical approval needed/obtained for study: ethics approval through the host institution Comments by study authors: not specified Miscellaneous outcomes by the review authors: information received from authors (Ireland 2019 [pers comm]): There were no withdrawals or exclusions.; number of participants analysed in each group: full sample as reported in the article; all participants stayed in the trial for the full length of time Correspondence: Michael J. Ireland, School of Psychology and Counselling, University of Southern Queensland, PO Box 4196, Springfield Central, Queensland 4300, Australia; Michael.Ireland@usq.edu.au
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Following the provision of signed consent and the completion of the first testing session, participants were randomly assigned to the intervention (n = 23) or control group (n = 21)." Quote: "A randomized control trial methodology (with 44 intern doctors) was utilized to test this hypothesis." Quote: "Conditions were equivalent pretest in prior with regards to experience with meditation/mindfulness (F = 0.08, p = 0.776, g 2 < 0.01), the appeal of meditation/ mindfulness (F = 0.73, p = 0.401, g 2 = 0.02), and expectations of the potential helpfulness of meditation/mindfulness (F < 0.01, p = 0.963, g 2 < 0.01)." Judgement comment: insufficient information about random‐sequence generation to permit judgement of ‘Low risk’ or ‘High risk’; RCT and verified baseline comparability for experience with meditation/mindfulness, appeal of meditation/mindfulness and expectations of mindfulness; insufficient information about baseline comparability (statistical significance) for sociodemographic characteristics (e.g. age, sex) and outcomes of interest (see T1 in Table 1)
Allocation concealment (selection bias)	Unclear risk	Judgement comment: insufficient information about allocation concealment to permit judgement of ‘Low risk’ or ‘High risk’
Blinding of participants and personnel (performance bias) Subjective outcomes	High risk	Judgement comment: blinding of participants and personnel probably not done (face‐to‐face intervention) and the outcome is likely to be influenced by lack of blinding
Blinding of outcome assessment (detection bias) Subjective outcomes	High risk	Judgement comment: insufficient information about blinding of outcome assessment; however, due to potential performance bias (no blinding of participants), the review authors judge that the participants' responses to questionnaires may be affected by the lack of blinding (i.e. knowledge and beliefs about intervention they received)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: information received from authors: no withdrawals or exclusions; all participants stayed in the trial for the full length of time
Selective reporting (reporting bias)	Low risk	Judgement comment: no study protocol or trial registration available but it is clear that the published reports include all expected outcomes, including those that were prespecified