How much could a low COVID-19 pandemic change the injury trends? A single-institute, retrospective cohort study

Abstract

Objectives: COVID-19 has changed the epidemiology of trauma. However, Taiwan is a country with a low COVID-19 threat, and people's daily lives have remained mostly unchanged during this period. The purpose of this study is to investigate whether the trend of trauma incidence and the service of trauma care is affected by the relatively minor COVID-19 pandemic in Taiwan.

Design: A single-institute, retrograde cohort study.

Setting: An observational study based on the trauma registry of Chang Gung Memorial Hospital (CGMH).

Participants: Trauma patients presented to the emergency department of CGMH in the period of 1 January to 30 June 2020 (week 1 to week 26) were designated as the COVID-19 group, with 1980 patients in total. Patients of the same period in 2015-2019 were designated as the pre-COVID-19 group, with 10 334 patients overall.

Primary and secondary outcome measures: The primary outcome is the incidence of trauma admission. Differences in trauma mechanism, severity, location and outcome were also compared in both groups.

Results: A decrease in trauma incidence during March and April 2020 was noticed. Significant change (p<0.001) in trauma mechanisms was discovered, with decreased burn (5.8% vs 3.6%) and assault (4.8% vs 1.2%), and increased transport accidents (43.2% vs 47.2%) and suicide (0.2% vs 1.0%) in the COVID-19 cohort. A shift in injury locations was also found with a 5% decrement of workplace injuries (19.8% vs 14.8%, p<0.001).

Conclusion: The limited COVID-19 outbreak in Taiwan has led to a decreased incidence of trauma patients, and the reduction is mostly attributed to the decline in workplace injuries.

Keywords: COVID-19; epidemiology; trauma management.

Figure 1

Weekly trend of trauma patient numbers in the COVID-19 era and pre-COVID-19 era and confirmed numbers of patients with COVID-19 in Taiwan. The yellow line represents the weekly trauma patient number in the COVID-19 era, and the green dot line represents the weekly trauma patient number in the pre-COVID-19 era. The red line is the weekly COVID-19 confirmed cases.

Figure 2

The comparison of injury locations (A) and mechanisms (B) between COVID-19 era and pre-COVID-19 era. The inside circle of the double pie chart represents the COVID-19 era, and the outer circle represents the pre-COVID-19 era. The subgroup of suicide injuries was combined to the assault injury subgroup in this graphic presentation due to its small sample size.

Figure 3

The scatter plot of the weekly percentage change of trauma patient volume between the COVID-19 cohort and the average of pre-COVID-19 cohort, and the piecewise linear regression model. The grey dots represent the percentage change in each week, presented in ratio manner in the y-axis (1.0=100%, −1.0=−100%). The blue line represents the piecewise linear regression model. The three red lines at the x-axis represent the three knots (week 10, week 12 and week 17) in the analysis. The green line at the y-axis signifies the baseline (0% change). (A) The model of overall trauma patients. (B) The model of injury by low-height mechanism subgroup. (C) The model of injury by transportation mechanism subgroup. (D) The model of injury in domicile location subgroup. (E) The model of injury in workplace location subgroup. (F) The model of injury in road location subgroup.

Figure 4

The relationship between COVID-19 case number and economic activities in Taiwan. At the upper half of the figure, the orange line (COVID) represents the confirmed COVID-19 case numbers, and the blue line (TAIEX, Taiwan Stock Exchange Capitalization Weighted Stock Index) represents the Taiwan stock index. At the bottom half of the figure, the green bar represents the monthly data of average daily rescue mission by the emergency medical technician (EMT), and the blue bar represents the monthly data of average daily traffic flow, presented by highway million vehicle/kilometres (MVK).