Seidel 2021.

Study characteristics
Methods	Study design: randomised controlled trial Study grouping: parallel group
Participants	Baseline characteristics Mindfulness Curriculum Age (mean ± SD): NR Sex (N (% female)): NR Sample size: NR Years of experience (mean ± SD): NR Control (wait list) Age (mean ± SD): NR Sex (N (% female)): NR Sample size: NR Years of experience (mean ± SD): NR Overall Age (mean ± SD): NR Sex (N (% female)): 71 (86%) Sample size: 83 Years of experience (mean ± SD): NR Included criteria: NR Excluded criteria: NR Pretreatment: NR Compliance rate: NR Response rate: NR Type of healthcare worker: quote: "Physicians, nurses, physician assistants, nurse practitioners, clinical nurse specialists, social workers, physical therapists, occupational therapists, pharmacists, psychologists, and chaplains"
Interventions	Intervention characteristics Mindfulness Curriculum Type of the intervention: Intervention type 2 ‐ to focus one’s attention away from the experience of stress Description of the intervention: "A series of 4 consecutive weekly 1‐hour classes on mindfulness (Building a Mindful CommUnity) and 15 minutes of daily practice." The number of sessions: 4 Duration of each session on average: 1 hour Duration of the entire intervention: 4 weeks Duration of the entire intervention short vs long: Short Intervention deliverer: NR Intervention form: Face‐to‐face classes AND at home practice by individual Control (wait list) 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 ‐ Depersonalisation Outcome type: ContinuousOutcome Maslach Burnout Inventory ‐ Personal accomplishment (lack of) Outcome type: ContinuousOutcome
Identification	Sponsorship source: "Portions of the project were funded by a Research AccelerationProgram grant from Carilion Clinic." Country: USA Setting: Academic medical centre Comments: The publication discusses two studies: 1 a quasi‐experimental study and another an RCT. The RCT details are abstracted here. Authors name: Laurie Walker Seidel Institution: Virginia Tech Email: wseidel@vt.edu Address: Roanoke City Public Schools Central Office, 40 Douglass Ave, Roanoke, VA 24012, USA Time period: 2016‐2017
Notes	MBI‐EE included in analysis 2.1 and 2.2
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were randomly assigned to either the intervention group or a waitlist control group. Sequence generation process insufficiently described.
Allocation concealment (selection bias)	Unclear risk	Unable to judge whether participants and/or investigators could possible foresee assignment
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding not possible
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	Of the 103 healthcare professionals who enroled, 83 completed the study (81%). Reasons not provide, nor whether missing was at random. Lost to follow‐up just below our pre‐defined cut‐off value.
Selective reporting (reporting bias)	Low risk	No trial registration or no study protocol reported. No indication of selective reporting.
Other bias	Unclear risk	No information on baseline differences. Contamination between groups ‐> There was a low attrition rate, supporting the effectiveness of offering each class multiple times within the week to expand choice and flexibility with the typical scheduling of a healthcare environment. The pattern of results may indicate that participants' knowing they were eventually to receive mindfulness training motivated members of the control group to improve their outlook. Although one cannot be certain about any post hoc explanation, it seems more likely that intervention participants shared what they learnt with those in the control group during the training period. It was observed during study 2 enrolment, for example, that several groupings of friends were assigned randomly to different conditions. Sharing information may explain why control participants increased mindful awareness during the intervention but did not continue that increase to the 6‐month posttest