Introduction: Simulation Exercises (SimEx) and After Action Reviews (AAR) are crucial tools for strengthening preparedness and response capabilities during emergencies. However, limited research has examined their application in mass gathering (MG) contexts. To address this, the World Health Organization (WHO) developed an MG practical guide for SimEx and AAR to enhance MG preparedness and readiness through structured evaluation. Methods: A scoping literature review and consultations with MG experts identified best practices and challenges in planning and executing SimEx and AAR for MGs. This informed an operational guide to streamline methodologies and support effective SimEx and AAR implementation. By integrating insights from event experts, the guide addresses specific MG challenges such as crowd control, emergency medical response, and multi-agency communication. Results: The research highlighted significant gaps in current methodologies, including a lack of clear objectives and tailored exercise designs for MG events. The guide addresses this by providing resources, including scenario templates for several health emergencies, such as crowd surges or outbreaks. These tools aim at improving stakeholder coordination, clarifying roles, and strengthening response mechanisms. Findings demonstrate that MG-focused SimEx and AAR resources enhance health security by identifying gaps, refining coordination, and ensuring readiness for real-world scenarios. Conclusion: The WHO MG practical guide for SimEx and AAR fosters structured learning, documents lessons, and provides mitigation measures to improve health security at MGs. Emphasizing a proactive, risk-based approach, it helps organizers manage public health risks and ensure safety. Emphasizing a proactive, risk-based approach, it enables organizers to manage public health risks, ensure safety, and foster continuous learning and resilience, preparing countries and event organizers to address evolving public health challenges at future mass gatherings.
Glaria et al. (Sun,) studied this question.