Impact of the COVID-19 pandemic on emergency CT head utilization in Ontario-an observational study of tertiary academic hospitals.

PURPOSE: To determine the impact of the Coronavirus disease-2019 (COVID-19) pandemic on the volume, indications, and results of CT heads performed in the emergency department (ED) at Canadian tertiary academic centers in Ontario METHODS: A retrospective review of consecutive CT head examinations ordered through the ED during the early stages of the COVID-19 pandemic in Canada (March 12-April 8, 2020) was performed and compared with that during the pre-COVID-19 period (February 12-March 10, 2020) CT reports were reviewed for the exam indication and the presence of predefined acute findings A two-sample t test was utilized to compare the cohorts Daily averages were calculated for all measures to control for the sample size difference between each period A p value < 0 05 was considered significant RESULTS: Of the total 751 CT head reports, 290 (38 6%) were ordered during the pandemic and 461 (61 4%) were ordered pre-pandemic The average daily volume of CT head orders decreased significantly during COVID-19 compared with that during pre-COVID-19 (10 4 scans/day vs 16 5 scans/day;p = 0 001) In terms of indications, the frequency of "non-traumatic ICH" was significantly lower during COVID-19 compared with that during pre-COVID-19 (p = 0 01) Also, there was a significant increase in acute findings on CT during COVID-19 compared with that during pre-COVID-19 (p = 0 001) CONCLUSION: The decreased volume of emergency CT heads performed during the COVID-19 pandemic was associated with a significant increase in the proportion of cases with acute findings This could be a result of the pandemic's influence on the health-seeking behavior of patients as well as the decision-making process of ordering clinicians