The use of emergency department electronic health data for syndromic surveillance to enhance public health surveillance programmes in England

Public health surveillance allows for the identification and monitoring of trends in human health. Syndromic surveillance is a relatively recent addition to these activities, offering the potential to monitor trends on a (near) real-time basis and is often more timely than may be possible through other, traditional, surveillance routes. Emergency department (ED) syndromic surveillance systems have been developed and successfully operated worldwide. The Public Health England Emergency Department Syndromic Surveillance System (EDSSS) was developed in preparation for the London 2012 Olympic and Paralympic Games and remains as a public health legacy of the Games. This thesis aimed to describe and provide evidence of how emergency department syndromic surveillance (as performed by EDSSS) provides additional benefit to public health surveillance and added value to emergency care services in England. Additionally the potential for further development and future improvements to public health surveillance is described. The EDSSS is shown here to have been successfully used to describe the impact of the rotavirus vaccine, indicating that EDSSS has the potential to be used for future rapid, stand alone, investigation of impact of vaccines in England. In the first cross-national study of its kind, the EDSSS (alongside OSCOUR, its counterpart in France) was successfully used to describe the changes in human health indicators during periods of poor air quality. In addition to reporting on both infectious and non-infectious disease, emergency department syndromic surveillance also successfully described the impacts of human behaviour on ED attendances. During the EURO 2016 football tournament ED attendances were found to differ from the expected during match periods, not only in France the host country, but also in the UK home nations where fans followed team progress from home. The EDSSS is also the first example of a syndromic surveillance system having input into the development of a standardised national dataset, which has been mandated across EDs in England. Primarily aimed to improve patient care and the wider workings of EDs, this improved data collection has resulted in improvements in the EDSSS itself, which was subsequently expanded from a small sentinel to truly national surveillance system. The standardisation of ED data collection and reporting, alongside improved geographical coverage and near real-time surveillance reporting, enabled rapid feedback on the impact of the COVID-19 pandemic on ED attendances in England. EDSSS described general trends in ED attendances, encompassing both infectious and non-infectious indicators, prompting the refinement of public health messaging, encouraging continued use of emergency care as required by the general public. The evidence presented in this thesis has demonstrated where the ED syndromic surveillance has added value for public health surveillance in England, utilising the system flexibility and timeliness of reporting. Successful collaborative working has provided the potential for future cross-system learning for further system development, as well as the ability to work at local, national and potentially international scales