Mind the data gap The use of unconventional data sources to assess the COVID-19 impact on people in vulnerable situations

According to the World Health Organization, population health monitoring is the first of ten essential public health operations. The emergence of novel data sources and monitoring approaches for public health surveillance is triggered by technological advances in data retrieval and analysis. Monitoring needs to have a central role when it comes to the determinants of health and health inequalities. Health inequalities monitoring provides evidence on who is being left behind and informs equity-oriented policies, programmes and practices.The overall aim of this thesis was to explore the potential of using existing data sources to monitor the health of people in vulnerable situations. As the impacts of COVID-19 were not evenly distributed across the population, with the greatest impacts falling on the least privileged in society, the pandemic emergency was used as a case study in this research work.The objective of chapter 1 was to compare the geographic and individual deprivation index in assessing the associations between individuals' socioeconomic position and risk of Sars-CoV-2 infection and disease severity in the Apulia from February to December 2020.The objective of chapter 2 was to assess the indirect impact of the COVID-19 pandemic, in terms of hospitalisation and mortality rates, among long-term care facilities’ residents in two Italian regions, Tuscany and Apulia, during 2020 in comparison with the pre-pandemic period.The objective of chapter 3 was to describe the extent and dynamics of the COVID-19 pandemic within the prison system of a large Italian region, Lombardy, and to report the infection prevention and control measures implemented.This research represents a proof of concept demonstrating that with the willingness and analytical capacity to extrapolate evidence from existing administrative data, health outcomes can be monitored even in neglected and extremely fragile populations. Administrative data have the potential to fuel high-quality empirical investigations and can help to advance our understanding of the relationship between human behaviour, social phenomenon and health in a way that has never been possible before. Health surveillance in these populations enables governments and other stakeholders to support evidence-informed action to tackle health inequities. The need to improve data collection, transfer, reporting, analysis and interventions on environmental and social determinants of health is pressing to reduce health inequities.