Abstract
Background
COVID-19 spread rapidly in 2020. To decrease its transmission rate, governments worldwide implemented social distancing. It has transformed people's physical and social activities. Such changes, differently influenced by age, might affect the incidence of traumatic injury.
Hypothesis
The impact of social distancing on traumatic injuries can influence differently by age.
Patients and methods
Nationwide randomized stratified sampling data (2018 to 2020, 1 million people per year) from Korean National Health Insurance Sharing Service were used. In this period, 364,690 patients with traumatic injuries were analyzed. People were grouped by age into 0–4, 5–19, 20–64, and ≥ 65 years. The incidence of traumatic injuries was compared between periods of social distancing and no social distancing. Social distancing levels, injured body parts, injury types, hospitalization rate, total medical cost per patient, weather, temperature, and holidays were also included for detailed analysis.
Results
Only the 5–19 age group showed the significant interaction of social distancing and traumatic injury. In this group, as the social distancing level increased, the injury incidence decreased especially during the spring and autumn semesters. However, the proportion of injuries requiring hospitalization and total medical cost per patient increased.
Discussion
Social distancing significantly affects the incidence of traumatic injuries for schooler (5–19 years). Considering that the incidence changed during these semesters, the restriction of school attendance, due to social distancing, may have caused the decrease. Reduced trauma in this group seems to be related to decrease of mild trauma, considering the hospitalization rate and total medical costs.
Level of evidence
III, retrospective cohort study.
Keywords: Coronavirus, Social distancing, Traumatic injury
1. Introduction
The first coronavirus disease 2019 (COVID-19) patient was diagnosed in December 2019, thereafter, COVID-19 spread rapidly worldwide [1]. There was no proven pharmaceutical agent or available vaccine in 2020 [2]. Thus, to reduce the global spread of COVID-19 and medical healthcare burdens, national governments implemented several public health interventions [3]. Social distancing, a method to control infectious diseases by reducing person-to-person contact, successfully contributed to decreasing the transmission rate of the COVID-19 [4].
Social distancing changes people's physical and social activities, and such changes affect the incidence of traumatic injury [5], [6]. Changes of activity are usually influenced differently by age: Since schoolers attend school during the semester regularly, the relationship between social distancing and childhood trauma may differ from that of adults [7]. However, few studies report the detailed impact of social distancing according to the age group or targeted large population. Given that globalization has amplified pandemic outbreaks and the possible occurrence of other pandemics, the analysis of the impact of social distancing on traumatic injury according to age is an important issue [8].
The authors hypothesized that social distancing would influence the incidence of traumatic injuries, and its effects can vary by age. In addition, it is necessary to analyze the overall data for a specific society or country because the social fear of infectious diseases can greatly affect individual visits to specific hospitals. Therefore, we investigated the changes in traumatic injuries in relation to social distancing using nationwide data.
2. Materials and methods
2.1. Social distancing of Seoul Metropolitan area
In South Korea, the first COVID-19 patient was reported on January 20, 2020, leading to an outbreak in mid-February [9]. To control infection spread, on March 22, 2020, the government ordered social distancing in the Seoul metropolitan area [10], which is highly urbanized; comprises Seoul, Incheon, and Gyeonggi province with 12,685 km2, compared to Île-de-France: 12,011 km2; houses around 26 million people (49.7% in 2018, 49.9 in 2019, 50.2% in 2020 of whole population). Since then, social distancing has been systematized. Social distancing level 1, the lenient form for sporadic outbreaks, maintains COVID-19 behavior by restricting the use of private or public facilities. Level 2, the intensified form for ongoing regional transmission, prohibits mass gathering by regulating the number of schoolers attending schools, starting online school, and encouraging work at home. Level 3, the lockdown form for strong restrictive quarantine or stay at home order (Supplementary Table 1). Same social distancing level was implemented in Seoul metroplitan area during the COVID-19 pandemic. The changes in the Seoul metropolitan area in 2020 were as follows: Level 2 – March 22 to May 5, August 17 to October 11, and November 24 to the end of 2020; Level 1 – May 6 to August 16 and October 12 to November 23. There was no Level 3 social distancing period in South Korea.
2.2. National sampling cohort of South Korea [National Health Insurance Sharing Service (NHISS)]
Almost all South Koreans are enrolled in the Korean National Health Insurance Program (97% of the population). The NHISS releases blinded random-sampling medical data of 1 million new patients each year since 2002 [11]. These data include age, sex, diagnosis, residental areas, and other patient characteristics. The patient's primary diagnosis in this sampling cohort was coded by the International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10). The codes starting with “S” imply traumatic injury.
2.3. Patient selection and investigated variables
This study was deemed exempt by Institutional Review Board. The impact of social distancing on traumatic injuries was retrospectively investigated using nationwide data. We compared the incidence of traumatic injury (S-code by ICD-10) between social distancing periods and no social distancing periods by only counting main diagnostic code. Multiple visit patients that had one major diagnosis were regarded as one injury. However, multiple visits patients with different major diagnoses were counted as new injuries for each major diagnoses. The patients who lived in Seoul Metropolitan area was included for the analysis. Since the data were de-identified and open to the public, informed consent was not required. The first two weeks of January were excluded because the incidence would be overestimated due to the risk of revisiting patients at the end of the previous year. The last week of December was excluded as the week was not completed. The data randomly selected one million people out of all health insurance customers, but the total numbers of claims were slightly different each year. A total of 47,928,961 people in 2018, 48,085,942 people in 2019, and 46,945,141 people in 2020 claimed national health insurance [12]. Therefore, the incidence was weighted for compensation according to total claims for each year (0.999 for 2018, 1.000 for 2019, and 0.979 for 2020).
The patient's age was grouped by considering their physical and social activity into 0–4 years (preschooler), 5–19 years (schooler), 20–65 years (adult), and ≥ 65 years (elderly). Injured body parts were classified as head/neck, trunk/proximal limb (shoulder/upper arm/hip/thigh), distal upper limb (elbow/forearm/wrist/hand), and distal lower limb (knee/lower leg/ankle/foot). The injury type was classified as a superficial wound, open wound, fracture, sprain/strain/dislocation, and others. The total medical cost per patient and injuries that required hospitalization were also investigated.
Sex, the implication of social distancing, social distancing level, weather (days without rain or snow, the mean clear days per week was 4.3 days ± 1.8), temperature (average temperature of the week, the mean temperature was 19.2 °C ± 9.9), and holiday (whether there was a holiday within the weekdays) were also included for analyses.
2.4. Statistical analysis
The effect of each variable on the weekly incidence of traumatic injuries was analyzed using a generalized linear model (Poisson regression). Multivariate analyses were performed with all variables to exclude or eliminate confounders. Those presenting the interaction with social distancing were also included in the multivariate analyses to evaluate the interaction effects of social distancing. Statistical significances were set for the p-value < 0.001 because of the large sample size. Statistical analyses were conducted using the free software R version 4.1.2 (R Foundation for Statistical Computing, Vienna, Austria).
3. Results
Demographics of all included characteristics are presented in Table 1 . Total traumatic injury cases were 120,088 in 2018 (32.9%), 125,236 in 2019 (34.3%), and 119,366 in 2020 (32.7%).
Table 1.
Demographics of all included cases according to age groups.
| Characteristics | All | 0–4 years | 5–19 years | 20–64 years | ≥ 65 years |
|---|---|---|---|---|---|
| Registered year | |||||
| 2018 | 120,088 (32.9) | 1,986 (34.4) | 17,368 (36.3) | 82,719 (32.5) | 18,015 (31.8) |
| 2019 | 125,236 (34.3) | 1,880 (32.6) | 18,724 (39.2) | 85,709 (33.7) | 18,923 (33.4) |
| 2020 | 119,366 (32.7) | 1,899 (32.9) | 11,726 (24.5) | 86,062 (33.8) | 19,679 (34.8) |
| Sex | |||||
| Male | 184,668 (50.6) | 3,294 (57.1) | 30,082 (62.9) | 129,120 (50.7) | 22,172 (39.2) |
| Female | 180,022 (49.4) | 2,471 (42.9) | 17,736 (37.1) | 125,370 (49.3) | 34,445 (60.8) |
| Injured body part | |||||
| Head and neck | 55,800 (15.3) | 2,832 (49.1) | 7,059 (14.8) | 37,737 (14.8) | 8,172 (14.4) |
| Trunk and proximal limbs | 120,596 (33.1) | 364 (6.3) | 7,645 (16) | 84,861 (33.3) | 27,726 (49) |
| Distal upper limb | 83,563 (22.9) | 1,512 (26.2) | 12,727 (26.6) | 60,277 (23.7) | 9,047 (16) |
| Distal lower limb | 104,731 (28.7) | 1,057 (18.3) | 20,387 (42.6) | 71,615 (28.1) | 11,672 (20.6) |
| Injury type | |||||
| Superficial injury | 43,469 (11.9) | 1,995 (34.6) | 7,815 (16.3) | 26,926 (10.6) | 6,733 (11.9) |
| Open wound | 40,875 (11.2) | 1,690 (29.3) | 4,846 (10.1) | 28,387 (11.2) | 5,952 (10.5) |
| Fracture | 38,115 (10.5) | 380 (6.6) | 4,977 (10.4) | 20,947 (8.2) | 11,811 (20.9) |
| Sprain/strain/dislocation | 219,777 (60.3) | 1,130 (19.6) | 27,783 (58.1) | 162,922 (64) | 27,942 (49.4) |
| Others | 22,454 (6.2) | 570 (9.9) | 2,397 (5) | 15,308 (6) | 4,179 (7.4) |
| Presence of Holiday | |||||
| Yes | 214,670 (58.9) | 3,582 (62.1) | 26,851 (56.2) | 151,359 (59.5) | 32,878 (58.1) |
| No | 150,020 (41.1) | 2,183 (37.9) | 20,967 (43.8) | 103,131 (40.5) | 23,739 (41.9) |
| Social distancing | |||||
| No | 269,174 (73.8) | 4,123 (71.5) | 38,036 (79.5) | 185,711 (73) | 41,304 (73) |
| In 2018, 2019 | 245,324 (67.3) | 3,866 (67.1) | 36,092 (75.5) | 168,428 (66.2) | 36,938 (65.2) |
| In 2020 | 23,850 (6.5) | 257 (4.5) | 1,944 (4.1) | 17,283 (6.8) | 4,366 (7.7) |
| Yes | 95,516 (26.2) | 1,642 (28.5) | 9,782 (20.5) | 68,779 (27) | 15,313 (27) |
| Level 1 | 53,636 (14.7) | 921 (16) | 6,118 (12.8) | 38,253 (15) | 8,344 (14.7) |
| Level 2 | 41,880 (11.5) | 721 (12.5) | 3,664 (7.7) | 30,526 (12) | 6,969 (12.3) |
Presented as Number of cases (%).
In multivariate analysis of the weekly incidence of injury by age group, significant interaction with social distancing was only observed in patients aged 5–19 years (bold, Table 2 ). Fig. 1, Fig. 2 present the weekly incidences of the entire population and each age group. Only those aged 5–19 years showed prominent decreases due to social distancing (Fig. 2b). Before social distancing, traumatic injury in those aged 5–19 years showed bimodal peak increases in spring and autumn, but these peaks disappeared during the period of social distancing in 2020.
Table 2.
Result of multivariate analysis of the weekly incidence of injury and interaction with social distancing.
| Variables | Coefficient (95% CI) | p-value | Interaction with the social distancing | |
|---|---|---|---|---|
| Coefficient (95% CI) | p-value | |||
| Sex | ||||
| Male | 0.012 (0.004 ∼ 0.019) | 0.003 | 0.001 (−0.013 ∼ 0.016) | 0.858 |
| Female | 1 (ref) | 1 (ref) | ||
| Age group (year) | ||||
| 0–4 | −1.563 (−1.595 ∼ −1.531) | < 0.001 | 0.017 (−0.043 ∼ 0.078) | 0.571 |
| 5–19 | −0.051 (−0.064 ∼ −0.037) | < 0.001 | −0.352 (−0.381 ∼ −0.323) | < 0.001 |
| 20–64 | 1.473 (1.462 ∼ 1.483) | < 0.001 | −0.002 (−0.022 ∼ 0.019) | 0.88 |
| 64– | 1 (ref) | 1 (ref) | ||
| Injured body part | ||||
| Trunk and proximal limbs | 0.786 (0.775 ∼ 0.798) | < 0.001 | −0.001 (−0.024 ∼ 0.022) | 0.926 |
| Distal upper limb | 0.382 (0.369 ∼ 0.394) | < 0.001 | −0.002 (−0.027 ∼ 0.022) | 0.849 |
| Distal lower limb | 0.625 (0.613 ∼ 0.637) | < 0.001 | −0.066 (−0.089 ∼ -0.042) | < 0.001 |
| Head & neck | 1 (ref) | 1 (ref) | ||
| Injury type | ||||
| Superficial injury | 0.573 (0.554 ∼ 0.592) | < 0.001 | 0.049 (0.012 ∼ 0.087) | 0.009 |
| Open wound | 0.552 (0.533 ∼ 0.571) | < 0.001 | 0.163 (0.126 ∼ 0.201) | < 0.001 |
| Fracture | 0.492 (0.473 ∼ 0.511) | < 0.001 | 0.018 (−0.02 ∼ 0.056) | 0.362 |
| Sprain/strain/dislocation | 2.18 (2.164 ∼ 2.196) | < 0.001 | 0.086 (0.054 ∼ 0.117) | < 0.001 |
| Others | 1 (ref) | 1 (ref) | ||
| Weather | ||||
| Number of clear day (0∼7d) | 0.000 (−0.002 ∼ 0.002) | 0.928 | 0.009 (0.005 ∼ 0.013) | < 0.001 |
| Mean temperature (°C) | 0.003 (0.002 ∼ 0.003) | < 0.001 | 0.008 (0.007 ∼ 0.009) | < 0.001 |
| Presence of Holiday | ||||
| Yes | −0.083 (−0.095 ∼ –0.071) | < 0.001 | −0.076 (−0.099 ∼ −0.052) | < 0.001 |
| No | 1 (ref) | 1 (ref) | ||
| Social distancing | ||||
| Yes | −0.237 (−0.288 ∼ –0.186) | < 0.001 | Not applicable | |
| No | 1 (ref) | |||
Fig. 1.
Weekly incidence of traumatic injury in total population. *SD 0: no social distancing, SD 1: level 1, SD 2: level 2.
Fig. 2.
Weekly incidence of traumatic injury by age groups (a) 0–4 years, (b) 5–19 years, (c) 20–64 years, and (d) ≥ 65 years.
For the subgroup analysis, only the age group 5–19 showed a clear decrease of injury incidence by social distancing level (Fig. 3 ). For those aged 5–19 years, the proportion of injured body parts and injury types did not show significant change due to social distancing level (Fig. 4 ). However, the proportion of injuries requiring hospitalization and total medical cost per patient increased with an increase in social distancing levels (Fig. 5 ).
Fig. 3.
Mean daily incidence of traumatic injury by age groups. *No SD: periods of no social distancing — 2018, 2019, and before March 22, 2020.
Fig. 4.
Percentage of traumatic injury in the age group of 5–19 years by social distancing level, (a) Injured body parts, and (b) Injury types.
Fig. 5.
Percentage of injuries requiring hospitalization and mean total medical cost per patient in the age group of 5–19 years. Injuries requiring hospitalization was 3.28% in periods of no social distancing, 3.55% in Level 1, and 4.42% in Level 2. Total medical cost per patient was 135,869 won in periods of no social distancing, 141,003 won in Level 1, and 168,299 won in Level.
4. Discussion
The study investigated the effect of social distancing on traumatic injury through a national sampling cohort. All included cases were classified into four age groups. In the age group 5–19 years, the incidence of traumatic injury was significantly reduced by social distancing (p < 0.001). However, the total medical cost per patient and requiring hospitalization was increased as the social distancing level increased. In the other age groups, social distancing and traumatic injury were not significantly related.
The vaccine was developed fairly quickly from 2020, inoculation programs began in February 26, 2021, in South Korea [13]. Due to these pharmaceutical limitations, the only way to control the transmission of COVID-19 in 2020 was by separating people to interrupt infection spread. This suggests that the pure social distancing effect on medical circumstances can be analyzed in 2020 compared to the pre-COVID-19 era. In addition, the Seoul metropolitan area, the subject of the study, is highly urbanized with a high population density, similar climate, and subtle demographic changes in recent years. Furthermore, this region was implemented for the same social distancing level. Thus, we tried to minimize the bias by targeting regions with the same characteristics to obtain a high representative population value. Primarily, this is the first study to compare different age groups using a large data sample – a national sampling cohort – to our knowledge.
In several studies, traumatic injury decreased when social distancing strengthened [5], [6]. However, the present results showed no significant decrease in traumatic injuries in the entire population due to social distancing except those aged 5–19 years (Fig. 1, Fig. 3). These differences seem to be originated from that the previous studies were generally conducted based on one or a few medical centers. Such research protocol cannot control people's behavior for hospital selection. For example, if an infectious disease is rampant in the area, non-COVID-19 patients may avoid visiting certain medical centers that mainly treat COVID-19 to prevent unintended infection [14]. Therefore, if the impact of social distancing is measured in only hospital-based data, there is a risk of under- or over-estimating traumatic injury incidence despite the lack of significant changes in overall incidence.
The most significant result is that traumatic injuries decreased significantly by social distancing only in the 5–19 years. During the social distancing Levels 1 and 2 in South Korea, more restrictions on school attendance or commencing online classes are included according to the level. Most in this age group are schoolers, which could partly explain the significant decrease of traumatic injury in this age group. This is supported by the fact that traumatic injuries did not decrease due to social distancing in the 0–4 years age group, representing preschoolers (Fig. 2a). In the 5–19 years age group, weekly incidences of 2018 and 2019 had bimodal peaks in the spring and autumn (Fig. 2b), and this pattern in the schoolers is explained due to the semester and vacation seasons [15]. However, these two characteristic peaks were not observed in 2020, and the incidence at spring and autumn semesters dropped like in the vacation periods. This also suggests that preventing certain outdoor activities in a specific group may significantly decrease traumatic occurrences. Trauma that can occur in school activities during physical education class or in after-school club activities was reduced during social distancing. Additionally, since mid-February 2020, before social distancing was implemented, the traumatic injury incidence had already reduced. Although social distancing was not officially enforced during those periods, the concept of social distancing was first proposed, and public education campaigns were promoted. Therefore, it can be considered that voluntary social distancing started in this period.
Social distancing greatly affected traumatic injuries in schoolers, but there was no significant proportional change in injured body parts or injury type (Fig. 4). The difference in the proportion of injured body parts and injury type reflects the characteristics of the injury mechanism [16]. This means that even though the overall traumatic injury was reduced, the ratio of traumatic mechanisms did not change significantly. On the contrary, other previous studies reported that injury subtype proportion was changed by social distancing [17], [18]. However, these analyses included lockdown periods – closing schools, restaurants, stopping non-essential works and ordering people to stay at home. Considering that South Korean government do not have implemented level 3 (lockdown) during COVID-19 era, which may explain the different results from our results. Staying-at-home order could increase the indoor activities, and accordingly, the injury mechanism and its subtype also would be changed. However, unlike severe form of social distancing, mild to moderate social distancing might not change the mechanism of the injury and it is the reason of no significant proportional change of the injury subtypes. Further study should be warranted to analyze the effect of more restrictive social distancing to traumatic injury. The proportion of patients requiring hospitalization and the total medical costs increased as the social distancing levels increased. This suggests that the number of mild injuries, which usually cost less and do not require hospitalization, had decreased.
There are some considerations to interpret the results of the study. First, the study was conducted only in a highly urbanized region. However, we tried to increase its representativeness by working on relatively uniform environmental areas and implemented the same social distancing level. Second, it is based on sampling data. However, sampling bias would have been minimized since the data comprised 1 million people by random stratified sampling. Third, this analysis used one million sampling data, so the results should be understood with caution. Even though some variables have statistical significance with social distancing, it must be interpreted with a graph because this study is a big data analysis. Fourth, we counted only main diagnostic code in multiple trauma patients and first visit with same major diagnostic code. This was because it was difficult to obtain detailed medical information because the original medical records could not be reviewed. Lastly, data for 2021 is not included. NHISS is processing these data and has therefore not released it. As mentioned earlier, it is difficult to estimate the pure effect of social distancing because the vaccine for COVID-19 has been available since early 2021. Therefore, the 2020 data would be appropriate.
5. Conclusion
Social distancing affects the incidence of traumatic injuries at 5–19 years but has no significant effect at other ages. For those aged 5–19 years, the incidence during the semester is greatly affected. However, the injury incidences during the summer vacation with social distancing were comparable to those during without social distancing. This would be due to the restriction of school attendance during social distancing. Considering the hospitalization rate and total medical costs, the decrease of trauma in this age group during the social distancing period seems to be mainly related to the decrease of mild trauma. However, further research is needed on the interaction between aging factor and traumatic injury during strong restriction policies.
Disclosure of interest
The authors declare that they have no competing interest.
Funding
None.
Author contribution
KB: data collection and analysis, statistics, article writing.
SSP: study design, article editing.
MSK: study design, data collection and analysis, statistics, article writing and editing.
Footnotes
Supplementary data (Supplementary table 1) associated with this article can be found, in the online version, at https://doi.org/10.1016/j.otsr.2023.103571.
Online Supplement. Supplementary data
References
- 1.Wang D., Hu B., Hu C., Zhu F., Liu X., Zhang J., et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus-Infected Pneumonia in Wuhan, China. JAMA. 2020;323:1061–1069. doi: 10.1001/jama.2020.1585. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Wiersinga W.J., Rhodes A., Cheng A.C., Peacock S.J., Prescott H.C. Pathophysiology, Transmission, Diagnosis, and Treatment of Coronavirus Disease 2019 (COVID-19): A Review. JAMA. 2020;324:782–793. doi: 10.1001/jama.2020.12839. [DOI] [PubMed] [Google Scholar]
- 3.Courtemanche C., Garuccio J., Le A., Pinkston J., Yelowitz A. Strong Social Distancing Measures In The United States Reduced The COVID-19 Growth Rate. Health Aff (Millwood) 2020;39:1237–1246. doi: 10.1377/hlthaff.2020.00608. [DOI] [PubMed] [Google Scholar]
- 4.Teslya A., Pham T.M., Godijk N.G., Kretzschmar M.E., Bootsma M.C.J., Rozhnova G. Impact of self-imposed prevention measures and short-term government-imposed social distancing on mitigating and delaying a COVID-19 epidemic: A modelling study. PLoS Med. 2020;17 doi: 10.1371/journal.pmed.1003166. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Chaiyachati B.H., Agawu A., Zorc J.J., Balamuth F. Trends in Pediatric Emergency Department Utilization after Institution of Coronavirus Disease-19 Mandatory Social Distancing. J Pediatr. 2020;226:274–277. doi: 10.1016/j.jpeds.2020.07.048. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Bolzinger M., Lopin G., Accadbled F., Sales de Gauzy J., Compagnon R. Pediatric traumatology in “green zone” during Covid-19 lockdown: A single-center study. Orthop Traumatol Surg Res. 2021:102946. doi: 10.1016/j.otsr.2021.102946. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Kang M.S., Kim H.S. Characteristics and trends of traumatic injuries in children visiting emergency departments in South Korea: A retrospective serial cross-sectional study using both nationwide-sample and single-institutional data. PLoS One. 2019;14 doi: 10.1371/journal.pone.0220798. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Naguib M.M., Ellstrom P., Jarhult J.D., Lundkvist A., Olsen B. Towards pandemic preparedness beyond COVID-19. Lancet Microbe. 2020;1:e185–e186. doi: 10.1016/S2666-5247(20)30088-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Kim J.Y., Choe P.G., Oh Y., Oh K.J., Kim J., Park S.J., et al. The First Case of 2019 Novel Coronavirus Pneumonia Imported into Korea from Wuhan, China: Implication for Infection Prevention and Control Measures. J Korean Med Sci. 2020;35:e61. doi: 10.3346/jkms.2020.35.e61. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Kim S., Ko Y., Kim Y.J., Jung E. The impact of social distancing and public behavior changes on COVID-19 transmission dynamics in the Republic of Korea. PLoS One. 2020;15 doi: 10.1371/journal.pone.0238684. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Bae K., Park S.S., Park J., Kang M.S. Analysis of Tertiary Hospital Utilization in Pediatric Orthopaedics: a Study Using Nationwide Sample Data from Korea. J Korean Med Sci. 2021;36 doi: 10.3346/jkms.2021.36.e289. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Korea National Health Insurance Sharing Service. 2020. [Health Insurance Statistical Yearbook (2018, 2019, 2020)] Available online: https://www.nhis.or.kr/nhis/together/wbhaec06300m01.do [assessed 4 June 2022].
- 13.Kwon S.L., Oh J. COVID-19 vaccination program in South Korea: A long journey toward a new normal. Health Policy Technol. 2022:100601. doi: 10.1016/j.hlpt.2022.100601. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Markham J.L., Richardson T., DePorre A., Teufel R.J.2nd., Hersh A.L., Fleegler E.W., et al. Inpatient Use and Outcomes at Children's Hospitals During the Early COVID-19 Pandemic. Pediatrics. 2021;147 doi: 10.1542/peds.2020-044735. [DOI] [PubMed] [Google Scholar]
- 15.Segal D., Slevin O., Aliev E., Borisov O., Khateeb B., Faour A., et al. Trends in the seasonal variation of paediatric fractures. J Child Orthop. 2018;12:614–621. doi: 10.1302/1863-2548.12.180114. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Hwang I.Y., Park J., Park S.S., Yang J., Kang M.S. Injury Characteristics and Predisposing Effects of Various Outdoor Traumatic Situations in Children and Adolescents. Clin Orthop Surg. 2021;13:423–435. doi: 10.4055/cios20242. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Regas I., Pichonnat M., Pluvy I., Obert L., Bellemère P., Chaves C., Loisel F. The impact of COVID-19 on hand surgery: A French retrospective comparative study in COVID-19 and non-COVID-19 hand trauma centers. Orthop Traumatol Surg Res. 2021;14:103118. doi: 10.1016/j.otsr.2021.103118. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Lapsa J., Bukola Badaki O., Xu A., Eaton C., Lee R.J., Ryan L. The COVID-19 Pandemic: Effects on Pediatric Fracture Patterns in the Emergency Department and Subspecialty Follow-up Care. J Pediatr Orthop. 2022;42:582–588. doi: 10.1097/BPO.0000000000002222. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.