Seasonal variation in medico-legal autopsies in Finland-a nationwide analysis of the period 2016-2021.

Both natural and unnatural mortality have seasonal variation. In spite of the established link between season and mortality, it is unclear whether medico-legal autopsies are subject to similar variation. Building on a nationwide dataset from the years 2016-2021, this short report aimed to analyse whether medico-legal autopsies are subject to seasonal variation in Finland. An electronic information system was queried for the monthly numbers of performed autopsies. Monthly and yearly trends were estimated with Kruskal-Wallis test and linear regression. A total of 50,457 medico-legal autopsies were performed during the 6-year study period. There were on average 29 to 47 autopsies per day, with an estimated annual decline of 1.8% (95% confidence interval 0.7-2.9%) over the study period. Monthly and yearly variation in autopsies was mostly minor and irregular; statistically significant differences were only observed between January and September as well as January and November (p < 0.05). As such, there appears to be little seasonal variation in medico-legal autopsies in Finland. A mild declining trend in the number of autopsies was observed. Future studies are invited to explore patterns of seasonality in other medico-legal systems, for example in those with generally lower autopsy rates than in Finland.