Spatial clustering and contextual factors associated with hospitalisation and deaths due to COVID-19 in Sweden: a geospatial nationwide ecological study

Abstract

IntroductionIn Sweden, thousands of hospitalisations and deaths due to COVID-19 were reported since the pandemic started. Considering the uneven spatial distribution of those severe outcomes at the municipality level, the objective of this study was, first, to identify high-risk areas for COVID-19 hospitalisations and deaths, and second, to determine the associated contextual factors with the uneven spatial distribution of both study outcomes in Sweden.MethodsThe existences of spatial autocorrelation of the standardised incidence (hospitalisations) ratio and standardised mortality ratio were investigated using Global Moran’s I test. Furthermore, we applied the retrospective Poisson spatial scan statistics to identify high-risk spatial clusters. The association between the contextual demographic and socioeconomic factors and the number of hospitalisations and deaths was estimated using a quasi-Poisson generalised additive regression model.ResultsTen high-risk spatial clusters of hospitalisations and six high-risk clusters of mortality were identified in Sweden from February 2020 to October 2020. The hospitalisations and deaths were associated with three contextual variables in a multivariate model: population density (inhabitants/km2) and the proportion of immigrants (%) showed a positive association with both outcomes, while the proportion of the population aged 65+ years (%) showed a negative association.ConclusionsOur study identified high-risk spatial clusters for hospitalisations and deaths due to COVID-19 and the association of population density, the proportion of immigrants and the proportion of people aged 65+ years with those severe outcomes. Results indicate where public health measures must be reinforced to improve sustained and future disease control and optimise the distribution of resources.

Geographic disparities in COVID-19 testing and outcomes in Florida

“…The identified high-risk hospitalization and mortality clusters in this study parallel reports from other studies examining placed-based inequities in these COVID-19 outcomes both in the US [ 50 , 67 , 68 , 72 ] and other countries [ 73 , 74 ].…”

“…These factors are positively associated with increased severity and risk of adverse COVID-19 outcomes [ 88 – 93 ]. Socioeconomic factors such as high poverty and limited access to healthy foods, household- and county-level overcrowding [ 74 , 94 – 96 ] may also have contributed to clustering of adverse COVID-19 outcomes in Southern Florida. In addition, counties in Southern Florida have higher burden of older population (≥ 65 years old) compared to counties in Northern Florida [ 97 ].…”

COVID-19 mortality and deprivation: pandemic, syndemic, and endemic health inequalities

“… 132 For example, Garcia 134 examined COVID-19 mortality rates across the 17 autonomous communities of Spain up to May 23, 2020, and found that a 1% increase in the gross domestic product per capita was associated with a 3·1% increase in COVID-19 mortality. One study from Sweden 123 found no significant association between COVID-19 mortality and area-level income or education.…”

Area-level socioeconomic deprivation, non-national residency, and Covid-19 incidence: A longitudinal spatiotemporal analysis in Germany

“…Previous research found that, over and above socioeconomic associations, districts with high proportion of non-nationals also showed a higher risk for measles incidence at district level in Germany, 40 and for Covid-19 associated deaths and hospitalisations in Sweden. 41 In addition, Covid-19 risk varied by ethnicity and specific measures of deprivation (particularly income and employment), but there was a disproportionate risk for ethnic minorities. 38 We found that not considering the role of non-nationals in the association between deprivation and Covid-19 leads to both underestimation (in Q2-Q4) and overestimation (in Q5) of socioeconomic deprivation.…”