Burnout among healthcare professionals in intensive care units (ICUs) is a prevalent concern with significant implications for both staff well-being and patient care outcomes. This protocol outlines a cluster randomized controlled trial designed to evaluate the effectiveness of the "Hello Bundle" intervention in reducing burnout among ICU healthcare professionals. The intervention comprises of various components aimed at fostering a positive and supportive work environment, including the distribution of Hello Campaign Posters, Email Reminders, Morning Huddles, Hello Jars, and Lead by Example initiatives. A hello board updated daily will be made available in each ICU. The trial will involve 146 participating centers affiliated with the ESICM, randomly assigned to intervention and control groups. Each center will have to include at least 50 HCP. Data will be collected from healthcare professionals at baseline, during the intervention period, and at follow-up, focusing on the prevalence of burnout, satisfaction with care, professional's intent to leave the ICU, and perceptions of the ethical climate. Statistical analysis will compare outcomes between intervention and control groups, aiming to demonstrate a reduction in the prevalence of burnout from 40% to 30% with an intra-class coefficient of 0.3 and a statistical power of 90%. This trial holds the potential to provide valuable insights into effective strategies for addressing burnout in ICU settings, ultimately benefiting both staff and patients.

ESICM affiliates (those registered on the ESICM mailing list) will receive a message in May 2024 with an invitation to take part in the cluster randomized trial. Two reminders will be sent until June 2024.

In each participating ICU, a dyad of investigators (physician and a nurse) will complete the ICU questionnaire (hospital size and ICU type, university affiliated, specialized ICU) and collect the willingness of each HCP to participate in the study. Participation rate will need to be >50% to be eligible for the trial. For those who are eligible, email addresses of HCPs will be required to be able to encourage them to implement the intervention. Online consent will be obtained from all participants to take part in the study and to use the data collected in the questionnaires. HCP characteristics, including age, sex, experience, and working conditions, will be collected. The dyad of investigators in each ICU will also set up a designated "Hello Board" every day with a date where staff members can write short greetings or positive messages to each other using markers or sticky notes. This can serve as a visual reminder to greet each other and foster a sense of camaraderie among team members.

The main components of the questionnaire include respondent's characteristics, visitation policies, team-family interactions, family-centeredness (VAS), and practices at the end of life. ICU-conflicts (VAS), symptoms of burnout, and a VAS to rank the ethical climate, satisfaction with work, and intent to leave the job. Symptoms of burnout will be measured using the validated version of the 22-item Maslach Burnout Inventory (MBI, Human Services version), which includes three subscales: emotional exhaustion (9 items), depersonalization (5 items), and personal accomplishment (8 items). Each item is scored from 0 (never) to 6 (every day). Respondents with high emotional exhaustion (≥27) and/or high depersonalization (≥10) scores will be considered to have symptoms of burnout.

Visual analogue scales (VAS) are used to assess the intensity of unidimensional measures. Two anchors are provided: for 0 (no symptom/lowest rating) and 10 (the most intense symptom/highest rating). VASs are convenient, easy, and rapid to administer and have been proved reliable for measuring a characteristic, subjective phenomenon, or attitude that is believed to range across a continuum of values and cannot easily be directly measured.

It is proposed to have a cluster randomized controlled trial with 146 participating centers, randomly assigned to intervention and control groups. All centers will be affiliated with ESICM, and data will be collected from HCP without involving any patient data. The primary endpoint is the prevalence of burnout measured by the Maslach Burnout Inventory (MBI) scale, between intervention and control groups with secondary endpoints including the comparison of burn-out prevalence before and after the intervention, HCP, satisfaction with work, HCP's intent to leave the ICU, and ethical climate rank and the importance of family and patient-centered care.

Statistical Analysis Quantitative variables will be described as median (interquartile range [IQR]) and will be compared between groups using the non-parametric Wilcoxon rank-sum test. Qualitative variables will be described as frequency (percentages) and will be compared between groups using Fisher's exact test.

Primary endpoint will be prevalence of burn out as defined by a high emotional exhaustion (score, ≥27) and/or high depersonalization (score, ≥10). Secondary endpoint will include individual components of the Maslach Burn Out Inventory and VAS, as well as HCP's intent to leave the ICU and ethical climate.

Primary and secondary analyses will be performed at an individual level adjusting for clustering. No imputation will be performed for missing variables.

Subgroup analyses will be conducted to explore potential moderators of intervention effectiveness.

Statistical analyses will be performed with R statistical software, version 3.4.3 (available online at http://www.r-project.org/) and packages 'lme4',and 'lmerTest'. A p value <0.05 will be considered significant.

Sample size:

Assuming an intra-class correlation of 0.3, 146 centers and 50 respondents per center, the study would allow to demonstrate a reduction in burnout prevalence from 40% to 30% with a statistical power of 90%.

How to get 200 centers, each including 50 healthcare providers? The steering committee includes 20 persons, each inviting 4 centers = 80 ESICM executive committee and council include 30 more people, each inciting 2 ICUs: 60 Note that immediately upon acceptance, centers complete the ICU characteristics form to be published anywhere to foster the group feeling.

The "Hello Bundle" intervention will be implemented in intervention group centers over a period of 30 days. The Hello board that is updated every day and regular communication will ensure adherence to the intervention components, and centers will receive support as needed to facilitate implementation. Training sessions and educational materials will be provided to ensure staff understanding and engagement with the intervention.

To allow control centers benefit from the intervention and avoid frustration, the intervention will be made possible (but optional) in the control centers 90 days after the end of the trial, and will not be followed by other measurements.

The intervention closed in the intervention groups on November 10, 2024. The collection of the post-intervention burn-out questionnaires has started and it is set to close on 20 December 2024.

Inclusion Criteria:

• healthcare professionals working in intensive care.

Exclusion Criteria:

• under 18 years of age healthcare professionals
• healthcare professionals not working in intensive care.

The methodologists will be blind of the study group and not aware on whether group A and B are control or intervention groups