Trends in Emergency Department Visits and Surgeries due to Traumatic Brain Injury During the COVID-19 Pandemic in Finland.

We aim to evaluate the changes in the incidence of TBI, trauma craniotomies, and craniectomies during the COVID-19 pandemic in Finland. This retrospective register study was conducted at three Finnish hospitals. We retrieved the numbers of emergency department (ED) visits, inpatient admissions, and trauma craniotomies and craniectomies due to TBI in the adult population from 2017 to 2020.We calculated the incidences per 100 000 inhabitants and compared the year 2020 to the reference years (2017-2019) by incidence rate ratios (IRR) with 95% confidence intervals. The incidence of TBI-related ED visits during the study period compared to the reference years started to decrease in March 2020 (IRR 0.86, CI: 0.73-1.02), and the lowest incidence was seen in April 2020 (IRR 0.83, CI: 0.68-1.01). The incidence of ED visits showed a second decrease in December (IRR 0.80, CI: 0.67-0.96). The incidence of concussion decreased during the national lockdown in March (IRR 0.80, CI 0.66-0.97). The incidence of ED visits due to TBI decreased after the declaration of national lockdown in spring 2020 and showed a second decrease during regional restrictions in December. In addition, the incidence of neurosurgically treated TBI decreased during restaurant restrictions in the spring.