Income-related inequality in health systems: a multi-country study on access, utilisation, and vaccination during the covid-19 pandemic

Introduction The COVID-19 pandemic placed unprecedented strain on global health systems, however, income-related health inequalities during the period remain underexplored. This thesis investigates income-related inequality in healthcare access, healthcare utilisation, and vaccination in 16 socioeconomically diverse countries during the pandemic. This thesis aims to: (1) situate the research in the literature, (2) assess income-related inequality in healthcare, (3) compare inequality across countries, (4) examine variation within countries, and (5) explore novel equality and efficiency approaches in healthcare. This thesis contributes to understanding inequalities during disruptions, offering insights to promote equitable access. Methods I conduct a replicable literature review on quantitative assessment of inequality in access, utilisation of health services, and vaccination, and apply variants of the concentration index to estimate income-related inequality in these areas. I then assess inequality-efficiency trade-offs in a financial incentives vaccination case study, and investigate sociodemographic characteristics associated with vaccine sentiment consistency. Finally, I conduct a synthesis of inequalities in health systems considering the estimates produced in this thesis. Results Significant pro-rich inequalities were identified in each country, particularly in lower and middle-income settings. Access and utilisation of appointments exhibited pro-rich inequality. Hospitalisation was utilised pro-poorly after overcoming access barriers. Vaccine sentiment was initially pro-rich, though inequality reduced over time. Financial incentives did not alter inequality in vaccination, but illustrate the importance of inequality measurement, while stated intention was the strongest predictor of vaccine uptake. Conclusion This thesis contextualises and quantifies income-related health inequality in several settings, finding a degree of inequality in each country. To address income-related inequality in healthcare, equality-sensitive policy makers need to adopt measures that focus on the vulnerable, and are based on recent and reliable evidence. This thesis sets out several considerations and implications to address inequality in healthcare.