Kalischer Wellander B, Lötvall J
Lakartidningen 118 (-) - [2021-07-23; online 2021-07-23]
Infection fatality ratio (IFR) in covid-19 is highly debated in international and Swedish press. In Sweden, three different estimates have been used to estimate mortality, based on statistics either from the Swedish National Board of Health and Welfare, and the Public Health Agency of Sweden, whereas excess mortality calculated by EuroMOMO. Mortality is based on death certificates, which can be accurate or erroneous, but previous analyses have suggested that over- and underdiagnosis usually even out. EuroMOMO on the other hand reports all-cause mortality compared to an estimated baseline. In view of high correlation between the different measures, we suggest that mortality is relatively correctly reported in Sweden. We discuss IFR internationally and in Sweden, and suggest that IFR in the Western world is approximately 0.5-1%. However, these numbers will change over time depending on immunity induced by vaccination efforts, but also the potential spread of new virus variants.