Objective: To estimate the weekly excess all-cause mortality in Norway and Sweden, and to estimate the years of life lost (YLL) attributed to COVID-19 in Sweden and the significance of mortality displacement.
Methods: We found expected mortality by taking the declining trend and the seasonality in mortality into account. From the excess mortality in Sweden in 2019/20, we estimated the YLL attributed to COVID-19 using the life expectancy in different age groups. We adjusted this estimate for possible displacement using an auto-regressive model for the year-to-year variations in excess mortality.
Results: We found that excess all-cause mortality over the epidemic year (July to July) 2019/20 was 517 (95%CI -12, 1074) in Norway and 4329 (3331, 5325) in Sweden. There were reported 255 COVID-19 related deaths in Norway, and 5741 in Sweden, that year. During the epidemic period March 11 – November 11, there were 6247 reported COVID-19 deaths and 5517 (4701, 6330) excess deaths in Sweden. The estimated number of life-years lost attributed to the more relaxed Swedish strategy was 45850 (13915, 80276) without adjusting for mortality displacement and 43073 (12160, 85451) after adjusting for possible displacement.