Impact of Vaccination, Health, and Healthcare Employment on COVID-19 Hospitalization Inequalities

Overview

This study analyzed how vaccination status, preexisting health conditions, and healthcare employment mediate socioeconomic disparities in COVID-19 hospitalization among Belgian adults. Using linked national registries, the research identified education-related inequalities in hospitalization risk and quantified the mediating roles of vaccination, underlying health, and healthcare professional status.

Background

COVID-19 has disproportionately affected individuals from lower socioeconomic groups, who face higher risks of infection and severe outcomes due to factors such as overcrowded living conditions, poorer baseline health, and limited access to preventive measures. Vaccination reduces severe COVID-19 risk but has shown unequal uptake, especially among lower-educated populations. This study investigates how vaccination, health status, and healthcare employment mediate the association between education and COVID-19 hospitalization within the syndemic framework of social determinants influencing pandemic outcomes.

Data Highlights

The study utilized data from six linked Belgian national registries covering COVID-19 testing, hospital admissions, vaccination records, sociodemographic characteristics, healthcare reimbursements, and healthcare professional licensing. The cohort included all adults with confirmed SARS-CoV-2 infection between September 2021 and September 2022 in the Walloon and Brussels regions, encompassing 42% of Belgium's population. The study period was stratified by dominant SARS-CoV-2 variants to account for differences in disease severity and vaccine effectiveness.

Key Findings

• Lower educational attainment was associated with a higher risk of COVID-19 hospitalization among infected adults.
• Vaccination status partially mediated the relationship between education level and hospitalization risk, with lower vaccination coverage in less educated groups contributing to increased hospitalization.
• Preexisting health conditions also mediated this association, as disadvantaged socioeconomic groups had higher rates of comorbidities increasing severe COVID-19 risk.
• Being licensed as a healthcare professional, used as a proxy for health literacy, influenced the association by potentially improving preventive behaviors and access to care.
• The combined mediating effects of vaccination, underlying health, and healthcare employment explained a significant portion of the socioeconomic disparities in COVID-19 hospitalization.

Clinical Implications

Clinicians and public health professionals should recognize that socioeconomic disparities in COVID-19 outcomes are partly driven by differential vaccination uptake and baseline health status. Targeted interventions to improve vaccination coverage and manage comorbidities in lower socioeconomic groups are essential. Additionally, leveraging healthcare professionals' role in health literacy may help reduce these inequalities.

Conclusion

This mediation analysis highlights that vaccination, preexisting health conditions, and healthcare employment status significantly mediate socioeconomic inequalities in COVID-19 hospitalization. Addressing these mediators is crucial to reducing health disparities during the ongoing pandemic.

References

1. World Health Organization 2020 -- COVID-19 Pandemic Declaration
2. Belgian Institute of Health (Sciensano) -- LINK-VACC Project Data
3. Belgian Vaccine Register (Vaccinnet+) -- COVID-19 Vaccination Data
4. Statistics Belgium (Statbel) -- Sociodemographic Data