The risk of severe COVID-19: hospital and ICU admission rates in Norway

Munkvik, M.; Vatten Alsnes, I.; Vatten, L.

Background: Epidemiological studies of COVID-19 with population based information may add to the knowledge needed to prioritise resources and advice on how restrictive measures should be targeted. This study provides admission rates to hospitals and intensive care units (ICU) in Norway, aiming to better understand the risk of severe COVID-19 infection. Methods: Data from official reports from The Norwegian Institute of Public Health (NIPH) and the Norwegian Directorate of Health were used to calculate admission rates to hospitals and to ICU per 100 000 inhabitants. We compared rates of hospitalisation between the four health regions and provide separate rates for Oslo. We also assessed national admissions to ICU stratified by age. Results: The admission rate in the south-eastern region was 3.1 per 100 000, and the rate for Oslo was 5.8. Compared to the western region (reference), the Oslo rate was 4.0 times (confidence interval (CI) 3.0-5.5) higher. In Norway as a whole, the rate of ICU admissions was 3.9 per 100 000, and in the age groups 60-69 and 70-79, ICU rates were 10.3 and 11.5, respectively. These rates were 9.5 (CI 6.3-14.3) and 10.6 (CI 6.9-16.2) times higher compared to people younger than 50 years. Conclusion: Hospital admissions due to Covid-19 are much higher in Oslo than anywhere else in Norway, and in the country as a whole, ICU admissions are highest among people 60-79 years of age. These results and more detailed data could provide better advice on how restrictions can be safely lessened.