Implementation of a workplace healthy lifestyle education intervention for metabolic syndrome risk reduction in Ethiopia: a mixed-methods process evaluation.

Background: The prevalence of metabolic syndrome among office workers is markedly high, highlighting an urgent need for effective workplace interventions. In response to this need, a theory-informed healthy lifestyle education intervention was developed and implemented among office workers in Ethiopia, resulting in significant reductions in key metabolic risk factors and improvements in health-related behaviours. However, understanding the implementation process, how the intervention worked in practice, under what conditions, and why is critical to inform scale-up, adaptation, and sustainability. This study aimed to evaluate the implementation process of a nine-month workplace-based healthy lifestyle education intervention, using the Programme Integrity Framework to assess implementation fidelity and the Consolidated Framework for Implementation Research to identify the barriers and facilitators influencing implementation. Methods: A convergent parallel mixed-methods process evaluation was conducted to assess the implementation process of a 9 month workplace intervention aimed to reduce risk for metabolic syndrome and improve knowledge, attitudes, and healthy lifestyle practices. A total of 226 employees were screened based on waist circumference and blood pressure and allocated to intervention and control groups using cluster randomisation. The intervention group received a personalised lifestyle education programme delivered by trained health promotion experts, while the control group received general health advice on non-communicable disease prevention. Implementation fidelity was assessed across the five domains of the Programme Integrity Framework: adherence, exposure, quality of delivery, participant responsiveness, and programme differentiation, using educator self-reports and direct observations conducted by the principal investigator. Contextual factors influencing implementation were examined using the five domains of the Consolidated Framework for Implementation Research (CFIR): intervention characteristics, outer setting, inner setting, characteristics of individuals, and process. These were assessed through participant self-reports, field notes from review meetings conducted at the third and sixth months, and open-ended questionnaire responses collected from 13 participants. Results: Implementation fidelity was high across adherence, exposure, quality of delivery, and participant responsiveness domains, indicating that the intervention was delivered as intended and well-received by participants. However, CFIR-informed contextual analysis identified several barriers to effective implementation, including unsupportive organisational cultures, limited leadership support, weak external policy backing, resource constraints, and community norms that were not always aligned with healthy lifestyle change. Conclusion: This study shows that a theory-informed lifestyle education intervention can be delivered with high fidelity and strong engagement among office workers, supporting workplaces as a promising NCD prevention setting. Sustainable scale-up will likely depend on task-sharing with trained non-specialist personnel and embedding workplace health promotion within organisational and policy systems. Future research should work on policy integration, scalability, long-term sustainability, equity, and cost-effectiveness. Clinical trial registration: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=385666&isClinicalTrial=False, identifier ACTRN12623000409673p.