Burnout syndrome is a serious occupational health problem affecting healthcare professionals worldwide. Defined by emotional exhaustion, depersonalisation, and reduced personal accomplishment, its consequences span mental health (depression, anxiety, insomnia, substance use), physical health (cardiovascular problems, chronic fatigue, gastrointestinal disorders), and professional performance (reduced quality of care, absenteeism, staff turnover). Primary care professionals are a particularly high-risk group due to sustained workload, administrative burden, and limited autonomy.

Despite the availability of evidence-based interventions - including Cognitive Behavioural Therapy, mindfulness, and organisational strategies - their implementation remains limited. Digital tools have shown promising results, but most mobile applications address stress generically and are costly to develop. Online communities via WhatsApp have emerged as an accessible, low-cost alternative with potential to deliver psychoeducational content and peer support effectively.

BurnOutCare is a structured 9-week pilot intervention delivered via WhatsApp, led by Mental Health Nursing professionals, comprising four modules: mindfulness, emotional regulation, conflict resolution, and burnout prevention. Content is shared three times per week using short texts, guided audio exercises, brief videos, interactive surveys, and infographics. A private individual channel provides personalised support.

The study aims to assess the feasibility and preliminary effectiveness of this approach in primary care professionals at OSI Barrualde-Galdakao (Basque Country, Spain), and to generate validated content and evidence to inform the future development of a purpose-built web/mobile health application for burnout prevention.

BACKGROUND AND RATIONALE Burnout syndrome, characterised by emotional exhaustion, depersonalisation, and reduced personal accomplishment (Maslach et al., 1996), represents one of the most pressing occupational health challenges in healthcare. Its consequences affect mental health (mood disorders, insomnia, substance use, increased psychotropic medication consumption), physical health (cardiovascular problems, chronic fatigue, migraine, gastrointestinal disorders including Irritable Bowel Syndrome), and work performance (reduced job satisfaction, quality of care, absenteeism, and staff turnover).

Primary care professionals are a particularly high-risk group. A meta-analysis found an overall burnout prevalence of approximately 50% among physicians globally. Primary care workers face specific risk factors: sustained physical and emotional workload, high administrative burden, limited autonomy, chronic time pressure, and reduced institutional recognition. The COVID-19 pandemic further exacerbated pre-existing burnout levels across all healthcare professions.

Evidence-based strategies include individual-focused interventions (CBT, mindfulness-based stress reduction, resilience training) and organisational interventions (workload reduction, improved staffing ratios, supportive team cultures). Digital tools - particularly mobile applications and online communities - have shown promise as accessible, scalable complements to these strategies. WhatsApp-based interventions offer structural advantages: near-universal adoption, no additional installation required, real-time interactivity, low cost, and multimedia content delivery capability. However, most digital tools address stress generically rather than targeting burnout specifically. A preliminary community-based pilot approach - validating content, format, and delivery before full application development - is both methodologically sound and resource-efficient.

STUDY DESIGN AND ETHICS BurnOutCare is a pre-experimental pilot study with a single-cohort pretest-posttest design, without a control group or randomisation. The study adheres to the CONSORT 2010 extension for pilot and feasibility trials (Eldridge et al., 2016), with randomisation-specific items marked as non-applicable. Primary objectives: (1) assess feasibility and effectiveness of the WhatsApp-based intervention; (2) obtain preliminary data to guide future definitive trial design and mobile health application development.

The study was approved by the Research Ethics Committee of OSI Barrualde-Galdakao (Protocol 08/25, Osakidetza-Basque Health Service). All participants provide written informed consent prior to enrolment in accordance with the Declaration of Helsinki and applicable Spanish data protection legislation.

INTERVENTION The BurnOutCare programme is a 9-week structured intervention delivered via WhatsApp, designed and led by Mental Health Nursing (PMH, RN) professionals in collaboration with clinical psychologists and a consultant psychiatrist.

Channel 1 - WhatsApp Distribution List: Structured content is shared three days per week across four sequential evidence-based modules: Module 1 - Mindfulness (weeks 1-2): guided breathing exercises, body scan meditations, mindful observation, psychoeducation on the neuroscience of stress. Module 2 - Emotional Regulation (weeks 3-4): identification and labelling of emotional states, cognitive restructuring, management of emotional reactivity in clinical settings. Module 3 - Conflict Resolution (weeks 5-6): assertiveness training, active listening, empathy development, strategies for managing workplace conflict. Module 4 - Burnout Prevention (weeks 7-9): recognition of early warning signs, self-care strategies, work-life balance techniques, professional boundary setting. Content formats include short psychoeducational texts, guided audio exercises, brief videos, interactive polls, and infographics, all designed to be consumed in under 10 minutes per delivery.

Channel 2 - Individual Private Channel: A private WhatsApp channel enabling confidential one-to-one interaction, personalised advice, query resolution, and follow-up on disengaged participants.

STATISTICAL ANALYSIS Analysis is conducted in three phases with expert support from the IIS Biobizkaia Biostatistics Team: (1) descriptive statistics with normality testing (Shapiro-Wilk); (2) pre-post outcome comparisons using paired t-tests or Wilcoxon signed-rank tests as appropriate, with effect sizes calculated as Hedges' g or biserial correlation r, both with 95% confidence intervals; (3) exploratory moderator analyses using mixed linear models and repeated-measures ANOVA to assess the influence of gender, years of experience, professional category, perceived workload, job satisfaction, and sleep quality. Significance threshold: p < 0.05.

FUNDING This study is funded by the Convocatoria Intramural Proyectos de Innovación Hasiberri 2024, IIS Biobizkaia (Instituto de Investigación Sanitaria Biobizkaia), Basque Country, Spain. The funding body has no role in study design, data collection, analysis, interpretation, or reporting decisions.

Inclusion Criteria:

• Active employment within the OSI Barrualde-Galdakao (Osakidetza-Basque Health Service) at the time of the study.
• Signed written informed consent prior to enrolment.
• Commitment to active participation in the programme over its 9-week duration.
• Access to a smartphone and the WhatsApp application

Exclusion Criteria:

• Non-acceptance of community rules, specifically mutual respect among participants.
• Use of the community for purposes unrelated to the programme objectives, such as self-promotion or discussion of topics unrelated to burnout prevention.

Individual participant data will not be shared publicly due to the small sample size of this pilot study, which could compromise participant confidentiality and anonymity. Aggregated and anonymised summary data are reported in the manuscript. Requests for additional information may be directed to the corresponding author (Juan José Pérez Moreno; JUANJOSE.PEREZMORENO@osakidetza.eus).