Abstract
Background
While many studies have found a high correlation between socio-economic inequalities and risk of Covid-19 deaths, there is reason to believe that much of this association is the product of differing levels of education.
Methods
We present multivariate models of fortnightly (n=60) Covid-19 deaths in 3108 US counties for the period 20 January 2020 to 10 May 2022. We model the direct (unmediated) effect of education, controlling for economy, race, geography, lack of vaccination, political orientation (vote Republican), poor health, and lack of preventative health behavior.
Findings
After controlling for correlated risk factors and indirect mechanisms that mediate education's impact on Covid-19 mortality, we find a strong direct (unmediated) correlation between low education and Covid-19 mortality (IRR [incidence rate ratios] = 1.17; 95% CI [confidence interval]: 1.15, 1.20). We theorize that this correlation reflects education's relationship with (1) collective cultures, such as norms of mask wearing, and (2) individual literacy, such as ability to engage with scientific communication.
Interpretation
Low education is strongly correlated with Covid-19 deaths, with an effect size of a university degree comparable to that of being over 65 in age. If this correlation is indeed causal, then it would imply that low education accounts for between 1 in 10 and 1 in 7 deaths in low education counties. Education should be conceptualized as a potential high-risk factor for Covid-19 death, and be taken into account when attempting to combat Covid-19 in disadvantaged communities. The effect of education cannot be reduced to its impact on vaccination or correlation with poor health or economic status, but it seems likely that low education communities have collective cultures that expose individuals to greater risks, and lack of individual literacy that limits engagement with public health messaging.
Keywords: Covid-19, Covid-19 mortality, Social determinants of health, Educational inequality, Health inequality