# Polarization and health-related behaviors and outcomes during the COVID-19 pandemic: a systematic review

## TL;DR

This review examines how political and affective polarization influenced health behaviors and outcomes during the pandemic, finding mixed but notable links to vaccine uptake and policy compliance.

## Contribution

The study provides a systematic review of how polarization affects health behaviors and outcomes during the pandemic, highlighting gaps in understanding and the need for better research methods.

## Key findings

- Higher political polarization was linked to lower vaccine uptake or intent.
- Associations between polarization and health outcomes were mixed and inconsistent.
- Poor reporting in studies limits the ability to assess bias and causal relationships.

## Abstract

Political and affective polarization are different, but related concepts, which can shape trust in authorities, interpretation of health messages, and health behaviors and outcomes. The aim of this study was to systematically review the research literature, exploring how affective and political polarization are associated with COVID-19-related health behaviors and outcomes.

From January 1, 2019 to November 27, 2024, we searched 12 electronic databases for studies about affective or political polarization and COVID-19-related outcomes, including preventive behaviors such as vaccination, compliance with policies, perceived risk and health outcomes. We included studies reporting primary data from participants of any age and gender, published in any language. Two independent reviewers, from a total of seven, conducted study selection, data extraction and risk of bias assessment. We synthesized findings narratively and reported them according to the PRISMA 2020 statement.

Of 2021 unique articles, we included nine cross-sectional studies, all conducted in the United States of America or Europe from 2020 to 2022. Four studies found associations between higher political polarization and lower COVID-19 vaccine uptake or intent. Reported associations between vaccination and affective polarization were mixed. Four studies of other COVID-19 attitudes or prevention measures found mixed results for both types of polarization. In one study, no association was found between polarization and changes in death in 2020 compared with 2015 to 2019. The risk of selection bias in included studies was high.

This systematic review found some evidence of associations between polarization and COVID-19 health-related behaviors and outcomes. Cohort studies are needed to understand the direction of association. More international and interdisciplinary approaches to the study of polarization are needed to generate evidence to inform health and public policy effectively and improve preparedness for future pandemics.

Image 1

•Understanding of how polarization impacts COVID-19 health behaviors is fragmented.•Higher political polarization was linked to lower COVID-19 vaccine uptake or intent.•Associations were more consistent for political than affective polarization.•Poor reporting of response rates and results limits assessment of risks of bias.•Cohort studies will improve assessment of causal links with COVID-19 outcomes.

Understanding of how polarization impacts COVID-19 health behaviors is fragmented.

Higher political polarization was linked to lower COVID-19 vaccine uptake or intent.

Associations were more consistent for political than affective polarization.

Poor reporting of response rates and results limits assessment of risks of bias.

Cohort studies will improve assessment of causal links with COVID-19 outcomes.