A comparison of COVID-19 epidemiological indicators in Sweden, Norway, Denmark, and Finland

Abstract

Aims: To compare the early impact of COVID-19 infections and mortality from February to July 2020 across the Nordic nations of Sweden, Norway, Denmark, and Finland through available public data sources and conduct a descriptive analysis of the potential factors that drove different epidemiological outcomes, with a focus on Sweden's response. Methods: COVID-19 cases, deaths, tests, case age distribution, and the difference between 2020 all-cause mortality and the average mortality of the previous 5 years were compared across nations. Patterns in cell phone mobility data, testing strategies, and seniors' care home deaths were also compared. Data for each nation were based on publicly available sources as of July 31, 2020. Results: Compared with its Nordic peers, Sweden had a higher incidence rate across all ages, a higher COVID-19-related death rate only partially explained by population demographics, a higher death rate in seniors' care, and higher all-cause mortality. Sweden had approximately half as much mobility change as its Nordic neighbours until April and followed similar rates as its neighbours from April to July. Denmark led its Nordic peers in testing rates, while Sweden had the highest cumulative test-positivity rate continuously from mid-March. Conclusions: COVID-19 pushed Sweden's health system to its capacity, exposed systemic weaknesses in the seniors' care system, and revealed challenges with implementing effective contact tracing and testing strategies while experiencing a high case burden. Looser government restrictions at the beginning of the outbreak are likely to have played a role in the impact of COVID-19 in Sweden. In an effort to improve epidemic control, Sweden has increased testing rates, implemented more restrictive prevention measures, and increased their intensive care unit bed capacity.

Keywords: COVID-19; COVID-19 mortality; Nordic; infectious disease prevention; infectious disease transmission; policy analysis; public health strategy.

Figure 1.

(a) Cumulative cases of COVID-19 per 1000 population; (b) cumulative tests for COVID-19 per 1000 population, seven day moving average; (c) cumulative deaths from COVID-19 per 1000 population. Case and test data are included until July 31; death data are included until July 5.

Figure 2.

Absolute difference between the all-cause mortality per 1000 population in 2020 and the average all-cause mortality per 1000 population in 2015 to 2019 for each week: (a) Sweden; (b) Norway; (c) Denmark; (d) Finland; and (e) Stockholm County in Sweden. Solid lines represent 2020 weekly all-cause mortality per 1000 population. Dotted lines represent the minimum and maximum observed weekly all-cause mortality per 1000 population from 2015 to 2019. All lines represent a 3-week moving average. Data are included until July 5.

Figure 3.

(a) Distribution of COVID-19 cases by age; (b) age-specific incidence of COVID-19 per 1000 population. Data are included until July 31.

Figure 4.

(a) Retail and recreation mobility, percent change from baseline; (b) residential mobility, percent change from baseline. All lines represent a 7-day moving average. Baseline values are region-specific and were established using a median of the corresponding day of the week from the period between January 3 and February 6, 2020. Note: Public holidays occurred for all four countries on April 10, April 13, and May 21; on May 1 for Norway/Sweden/Finland; on June 19 for Sweden/Finland; on April 9 and June 1 for Norway/Denmark; and May 8, May 22, and June 5 for Denmark. Data are included until July 31 and are from the Google Community Mobility Report.