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. 2021 Mar;36(3):287-298.
doi: 10.1007/s10654-021-00732-w. Epub 2021 Mar 11.

Risk factors for COVID-19 diagnosis, hospitalization, and subsequent all-cause mortality in Sweden: a nationwide study

Jonathan Bergman  1 , Marcel Ballin  1   2 , Anna Nordström  2   3 , Peter Nordström  4
Affiliations

Risk factors for COVID-19 diagnosis, hospitalization, and subsequent all-cause mortality in Sweden: a nationwide study

Jonathan Bergman et al. Eur J Epidemiol. 2021 Mar.

Abstract

We conducted a nationwide, registry-based study to investigate the importance of 34 potential risk factors for coronavirus disease 2019 (COVID-19) diagnosis, hospitalization (with or without intensive care unit [ICU] admission), and subsequent all-cause mortality. The study population comprised all COVID-19 cases confirmed in Sweden by mid-September 2020 (68,575 non-hospitalized, 2494 ICU hospitalized, and 13,589 non-ICU hospitalized) and 434,081 randomly sampled general-population controls. Older age was the strongest risk factor for hospitalization, although the odds of ICU hospitalization decreased after 60-69 years and, after controlling for other risk factors, the odds of non-ICU hospitalization showed no trend after 40-49 years. Residence in a long-term care facility was associated with non-ICU hospitalization. Male sex and the presence of at least one investigated comorbidity or prescription medication were associated with both ICU and non-ICU hospitalization. Three comorbidities associated with both ICU and non-ICU hospitalization were asthma, hypertension, and Down syndrome. History of cancer was not associated with COVID-19 hospitalization, but cancer in the past year was associated with non-ICU hospitalization, after controlling for other risk factors. Cardiovascular disease was weakly associated with non-ICU hospitalization for COVID-19, but not with ICU hospitalization, after adjustment for other risk factors. Excess mortality was observed in both hospitalized and non-hospitalized COVID-19 cases. These results confirm that severe COVID-19 is related to age, sex, and comorbidity in general. The study provides new evidence that hypertension, asthma, Down syndrome, and residence in a long-term care facility are associated with severe COVID-19.

Keywords: COVID-19; Case–control study; Cohort study; Coronavirus; Epidemiology; SARS-CoV-2.

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Conflict of interest statement

The authors declare that they have no conflicts of interest.

Figures

Fig. 1
Fig. 1
Risk of all-cause mortality in Swedish COVID-19 cases (intensive care unit [ICU] hospitalized, non-ICU hospitalized, and diagnosed only) confirmed by mid-September 2020 and in general-population controls
See this image and copyright information in PMC

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