Impact of the COVID-19 Pandemic on Trauma Encounters

Objectives The Coronavirus Disease 2019 pandemic has affected the health care system significantly. We compare 2019 to 2020 to evaluate how trauma encounters has changed during the pandemic. Methods Retrospective analysis using a large US health care system to compare trauma demographics, volumes, mechanisms of injury, and outcomes. Statistical analysis was used to evaluate for significant differences comparing 2019 to 2020. Results Data was collected from 88 hospitals across 18 states. 169 892 patients were included in the study. There were 6.3% fewer trauma patient encounters in 2020 compared to 2019. Mechanism of injury was significantly different between 2019 and 2020 with less blunt injuries (89.64% vs. 88.39%, P < .001), more burn injuries (1.84% vs. 2.00%, P = .021), and more penetrating injuries (8.58% vs. 9.75%, P < .001). Compared to 2019, patients in 2020 had higher mortality (2.62% vs. 2.88%, P < .001), and longer hospital LOS (3.92 ± 6.90 vs. 4.06 ± 6.56, P < .001). Conclusion The COVID-19 pandemic has significantly affected trauma patient demographics, LOS, mechanism of injury, and mortality.


Introduction
The Coronavirus Disease 2019 (COVID-19) pandemic has significantly affected the United States health care system including trauma centers and patients. [1][2][3] During the initial months of the pandemic, domestic violence calls have increased by 25% while traffic congestion has diminished accompanying a >60% decrease in local travel in the United States. [4][5][6] While some areas were seeing decreases in motor vehicle accidents, motor vehicle fatalities were increasing likely from the public driving faster on highways. 7,8 A pandemic of this magnitude is rare and provides a critical and unique time to evaluate trends in trauma. Previous studies have shown decreases in trauma admissions and increases in penetrating and violence related trauma. [9][10][11][12][13][14][15][16] Evaluation of the United States traumatic injuries during 2020 is warranted to evaluate how fluctuations has changed during a unique period in history and help anticipate future trends during similar situations.

Methods
Monthly trauma volumes from 88 hospitals in 18 states were queried from a large US health care system database from January 2019 to December 2020 identifying 172,061 patients. Patients with missing data on gender (n = 371), Injury Severity Score (ISS) (n = 202), not having admission dates from January 2019 to December 2020 (n = 21), and missing ICD-10 codes on mechanism of injury (n = 1575) were excluded. A total of 169 892 patients with 173 936 trauma encounters were included to compare monthly trauma volumes in the pre-pandemic period (January to December 2019) to the pandemic period (January to December 2020). Data on age, sex, race/ ethnicity, hospital length of stay (LOS), ISS, and discharge description were extracted. Mechanism of injury was classified based on the ICD-10 codes. Categorical variables were reported as percentages and continuous variables reported as means. Chi-square tests were used to compare categorical variables and two-sample t-test was used to compare continuous variables. P-value threshold of P < .05 was used for 2-tailed tests. The study was approved by the hospitals Institutional Review Board. Data analysis was performed using SAS 9.4 and R version 4.0.2.
Compared to 2019, there was a 6.3% decrease in volume in 2020 with a decrease in volume beginning in March of 2020 that persisted the remainder of the year with a gradual increase to pre-COVID volumes ( Figure 1). The initial 20.5% decrease in trauma volumes occurred in April 2020. A second decrease in trauma volume occurs in November 2020 with a nadir 22.1% decrease in trauma volume in December 2020.
Significant changes in mechanism of injury and ISS begin in March ( Table 2). Mechanism of injury are significantly different between 2019 and 2020 with less blunt injuries (89.64% vs. 88.39%, P < .001), more burn injuries (1.84% vs. 2.00%, P = .021), and more penetrating injuries (8.58% vs. 9.75%, P < .001). Penetrating trauma remains increased for 2020 compared to 2019 until December where there is a percentage decrease in all mechanisms of injury ( Figure 2).

Discussion
Since the COVID-19 pandemic, trauma volumes of hospitals have substantially decreased. This is suspected  16 violence related injuries increased 17% to 46%. This study identified a concurrent decrease in blunt trauma accompanying the increased proportions of penetrating trauma which is similar to previous studies. This may suggest that while stay at home orders may affect blunt trauma such as motor vehicle accidents, violence related injuries continue and may be exacerbated by socioeconomic stressors inflicted by the pandemic. A second inflection in trauma volumes and mechanism of injury occurs in November 2020 during the height of the third wave of positive COVID-19 cases. This decrease in volume by 22.1% in December accompanies a decrease in    Significant P-values bolded (P < .05).
Abbreviations: ISS, injury severity score; LOS, length of stay.
all mechanisms of injury; 23.1% blunt, 29.6% in burns, and 9.8% penetrating. This is the first month during the pandemic where penetrating trauma has decreased. Changes in trauma volume and mechanism during the beginning of 2020 may be attributed to stay-at-home orders while the second decrease may be from other causes and require further investigation. There were significant changes in hospital LOS and mortality in 2020. The difference in hospital LOS is relatively small and coincides with no difference in ICU LOS found in previous reports. 20 While mortality differences fluctuated throughout the year, the greatest mortality among trauma patients in 2020 occurred in March (3.06%) and April (3.11%), then again in November (3.10%) and December (3.56%). The peaks in mortality occur during the initial stay-at-home orders and the third peak of COVID-19 positivity yet the explanation for this change in mortality is difficult to ascertain. Kaufman et al 25 found that 2.6% of trauma patients tested positive for COVID-19 and had an increased risk of death (OR 6.05, 95% CI 2.29, 15.99) when matched with COVID-19 negative trauma patients. Conversely, Ghafil et al 20 found no difference in mortality during the COVID-19 pandemic. Further studies regarding the change in outcomes during the COVID-19 pandemic are warranted as patient and health care system factors may help explain these differences.
Limitations present in this study include the granularity and inability to identify more specific mechanisms of injury such as motor vehicle crashes, gunshot wounds, or knife wounds. While most previous studies are focused in highly populated cities, this study involves multiple hospitals spread among multiple states therefore the distribution of the collected data may affect results. Additionally, hospitals may not have equal experiences as state and local responses to the COVID-19 pandemic have varied.

Conclusion
Trauma volumes have dramatically changed during the COVID-19 pandemic with an initial decrease in March and a second decrease in November. Mechanism of injury has also seen dramatic changes with increases in penetrating trauma. Lastly, trauma mortality appears to have fluctuated with the COVID-19 pandemic. Further studies detailing these unique inflection points may help describe how human behavior affects trauma patients.

Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.