The role of socio-economic determinants in SARS-CoV-2 health outcomes: systematic review of population-based studies.

IntroductionThe COVID-19 pandemic has accentuated a health-wealth gradient, reminiscent of patterns observed in previous influenza pandemics. This systematic review, employing a population-based approach, aims to delve into the etiological and prognostic roles of socio-economic factors on COVID-19 outcomes during the pandemics initial phase. MethodsOur search spanned PubMed, Embase, WHO COVID-19 Global literature, and PsycINFO databases from January 2020 to April 7, 2021, focusing on English peer-reviewed articles. We examined the impact of socio-economic determinants on SARS-CoV-2 infection, COVID-19 related hospitalization, ICU admission, mechanical ventilation, mortality, and a range of prognostic outcomes including quality of life and mental health. ResultsThe initial search resulted in 9,701 records after removal of duplicates. Out of hundred articles that met our review criteria, 67 discussed the etiological role of socio-economic factors, 25 addressed the prognostic role, and 8 covered both. Fifty-nine percent of the studies were from the United States of America and the United Kingdom, highlighting an increased risk of infection and severity among their Black, Asian, and Hispanic populations. Lower-income groups, crowded households, and, higher socio-economic deprivation were associated with higher COVID-19 incidence and severity. Results regarding educational status varied across different waves. ConclusionPopulations groups with disadvantaged socio-economic positions and certain ethnic and racial backgrounds face a higher risk of SARS-CoV-2 infection and poorer COVID-19 outcomes. Our findings underscore the need for incorporating social determinants into routine health surveillance and monitoring, suggesting an avenue for targeted interventions. What is already known on this topicThe association between socio-economic factors and outcomes, observed during the COVID-19 pandemic and other influenza epidemics, indicates a significant health-wealth gradient. Higher mortality and worse health outcomes are observed in the most disadvantaged groups of the population What this study addsThis study lays out a comprehensive review of population-based studies, representative of the general population, on the etiological and prognostic role of socio-economic characteristics in COVID-19 outcomes covering studies across 22 countries. Our results show that population-based studies from countries in Asia, Africa, Latin America, and continental Europe were limited in the early phase of the pandemic and highlight the importance of socio-economic characteristics, alongside comorbidities, for predicting SARS-CoV-2 infection and COVID-19 severity. How this study might affect research, practice or policyThis evidence shows a gap in the literature in countries other than the USA and the UK and on the role of socio-economic characteristics in long-term COVID-19 outcomes. Social inequalities need to be at the heart of infectious disease monitoring and surveillance to decrease the gap in adverse outcomes between patients of different socio-economic profiles.