Inequitable impact of infection: social gradients in severe COVID-19 outcomes among all confirmed SARS-CoV-2 cases during the first pandemic wave in Sweden

Abstract

BackgroundThe backdrop of the ubiquitous social inequalities has increasingly come into foreground in research on the COVID-19 pandemic, but the lack of high-quality population-based studies limits our understanding of the inequitable outcomes of the disease. The present study seeks to estimate social gradients in COVID-19 hospitalisations, intensive care admissions and death by education, income and country of birth, while taking into account disparities in comorbidities.MethodsWe used a register-based retrospective open cohort design enrolling all 74 659 confirmed SARS-CoV-2-positive cases aged >25 years in Sweden during the first wave of the pandemic (until 14 September 2020). Information was retrieved from multiple registers and linked by the unique Swedish personal identity number concerning COVID-19 case identification; COVID-19 hospitalisations, intensive care admissions and death; comorbidities as measured by the Charlson Comorbidity Index; and sociodemographic information. Social gradients were estimated by the Relative Index of Inequality (RII) using Cox regression.ResultsAdjusted analyses showed significant social gradients in COVID-19 hospitalisation, intensive care admission, across education, income and country of birth, which were unaffected by adjustment for comorbidities. Education and country of birth gradients were stronger for hospitalisation and intensive care admissions but small to non-existent for death. In contrast, income gradients were consistent across all three COVID-19 outcomes.ConclusionSocial gradients in severe COVID-19 outcomes are widespread in Sweden, but appear to be unrelated to pre-existing health disparities. Inequitable outcomes of SARS-CoV-2 infection may therefore be at least partially avoidable and could rely on equitable management of confirmed COVID-19 cases.

The social gradient in COVID-19 vaccination intentions and the role of solidarity beliefs among adolescents

“…Furthermore, given that vaccines decrease the transferability of COVID-19 (e.g., Harris et al, 2021 ; Levine-Tiefenbrun et al, 2021 ), high vaccination rates reduce the infection pressure on vulnerable groups within society. In a broader sense, our study also provides results that have implications for stratification research, finding pronounced differences by migration background in COVID-19-related hospitalizations and intensive care unit admissions (e.g., Gustafsson et al, 2021 ).…”

Association between pharmaceutical modulation of oestrogen in postmenopausal women in Sweden and death due to COVID-19: a cohort study

“…Adjusting for income and education is important as we have previously shown how these affect the risk of dying due to COVID-19 in Sweden. 19 …”

“…In our study, the effect of increased systemic oestrogen levels on reducing the risk of COVID-19 death remained significant after adjusting for education level and income, both factors known to influence COVID-19 outcome,18 further supporting the protective role of oestrogen in women. Adjusting for income and education is important as we have previously shown how these affect the risk of dying due to COVID-19 in Sweden 19…”

Severe COVID‐19 in people 55 and older during the first year of the pandemic in Sweden

“…The associations became stronger after exclusion of individuals with addresses geocoded within 25 m of a nursing home. Social gradients in severe COVID‐19 outcomes in Sweden—unrelated to pre‐existing health disparities—have been demonstrated in a register‐based study in a cohort of infected individuals; however, the study did not consider assisted living [ 24 ].…”