Leaving a viable public health legacy and sustainable improvements in health infrastructure and capacity should be key for mass gatherings (MGs). Legacy includes improvements in health systems, health behaviors and delivering future MGs. Legacy planning and evaluation should be considered early in planning however, they are often neglected due to lack of funding to support, embed learning and maintain a sustainable legacy, and often favored over the event running smoothly.

Building on the Public Health for Mass Gatherings: Key Considerations (KC2) (2015), an updated literature review will identify new evidence for evaluating MGs and their legacy. This review will inform the development of updated resources to reflect the changing global health landscape and learning from MGs hosted during COVID-19, which can inform ways of better embedding legacy and evaluation in planning and post-event.

A systematic literature review methodology will be used. Electronic databases will be searched for relevant publications and grey literature of a wide range of MGs globally, focusing on evaluations, MG legacies, and impacts. Searches for specific technical areas e.g., surveillance, will also take place.

The literature review undertaken to develop the KC2 chapter identified limited publications. The increased interest in this field, should lead to an improved evidence base while recognizing evidence for long-term evaluation and legacy impact may still be more restricted due to the challenges of undertaking these studies. Recent literature will likely reflect work undertaken to deliver MGs during COVID-19, which will be included to identify good practice and transferable learning.

Key findings of the review will be published, and the evidence base will be used to update the evaluation and legacy chapter of the KC2. There are also plans to develop a MG evaluation and legacy tool that will be applicable beyond the major high-profile funded events.