High excess mortality in areas with young and socially vulnerable populations during the COVID-19 outbreak in Stockholm Region, Sweden

Abstract

Introduction: We aimed to describe the distribution of excess mortality (EM) during the first weeks of the COVID-19 outbreak in the Stockholm Region, Sweden, according to age, sex and sociodemographic context.

Methods: Weekly all-cause mortality data were obtained from Statistics Sweden for the period 1 January 2015 to 17 May 2020. EM during the first 20 weeks of 2020 was estimated by comparing observed mortality rates with expected mortality rates during the five previous years (N=2 379 792). EM variation by socioeconomic status (tertiles of income, education, Swedish-born, gainful employment) and age distribution (share of 70+-year-old persons) was explored based on Demographic Statistics Area (DeSO) data.

Results: EM was first detected during the week of 23-29 March 2020. During the peak week of the epidemic (6-12 April 2020), an EM of 150% was observed (152% in 80+-year-old women; 183% in 80+-year-old men). During the same week, the highest EM was observed for DeSOs with lowest income (171%), lowest education (162%), lowest share of Swedish-born (178%) and lowest share of gainfully employed residents (174%). EM was further increased in areas with higher versus lower proportion of younger people (magnitude of increase: 1.2-1.7 times depending on socioeconomic measure).

Conclusion: Living in areas characterised by lower socioeconomic status and younger populations was linked to excess mortality during the COVID-19 pandemic in the Stockholm Region. These conditions might have facilitated viral spread. Our findings highlight the well-documented vulnerability linked to increasing age and sociodemographic context for COVID-19-related death.

Keywords: Descriptive study; epidemiology; public health.

Figure 1

All-cause mortality rates and excess mortality in the Stockholm Region (N=2 379 792), Sweden, during the first 20 weeks of 2020. The dark blue line indicates the mortality rates per 100 000 persons-week reported on the logarithmic scale. The light blue lines indicate 95% CIs for the average mortality rates corresponding to the five previous years. Bars depict the excess mortality during the first 20 weeks of 2020 in comparison with the average from five previous years.

Figure 2

Average excess mortality across the 1287 DeSOs of the Stockholm Region (N=2 379 792), Sweden, by levels of socioeconomic indicators during the COVID-19 outbreak (ie, 9 March 2020 to 12 April 2020). Demographic Statistics Areas (DeSO) produced by Statistics Sweden gather groups of around 1500 inhabitants (range: 700 and 2700) and are built within the municipal boundaries across Sweden. Excess mortality calculated comparing mortality rates during weeks 11–15 of 2020 with the average mortality rates recorded for the corresponding weeks during the five previous years. Socioeconomic indicators were categorised into low, medium or high according to tertiles of the DeSO distribution.

Figure 3

Average excess mortality across the 1287 DeSOs of the Stockholm Region (N=2 379 792), Sweden, by levels of socioeconomic indicators and share of 70+-year-old people during the peak of the COVID-19 outbreak (ie, week of 6–12 April 2020). Demographic Statistics Areas (DeSO) produced by Statistics Sweden gather groups of around 1500 inhabitants (range: 700 and 2700) and are built within the municipal boundaries across Sweden. Excess mortality calculated comparing mortality rates during the week of 6–12 April 2020 with the average mortality rates recorded for the corresponding weeks during the five previous years. Socioeconomic indicators were categorised into low, medium or high according to tertiles of the DeSO distribution, and further divided according to the share of 70+-year-old persons (below vs above the median) within each tertile.