2.1

Study design

The study was conducted retrospectively at a tertiary care hospital with a level-one trauma center in one of the 10 provinces affected by the earthquake in Turkey’s Southeastern Anatolia Region. The focus of the study was patients with isolated blunt thoracic trauma resulting from earthquakes. These patients presented to the emergency department of ……Hospital between February 6, 2023, and February 28, 2023. Injuries attributed to the earthquake were identified based on the information available in the medical records, including mentions of the earthquake as the cause of injury, narratives of the incident, such as entrapment or structural collapses resulting from the earthquake, and clinical documentation specifying ‘earthquake-related injury.’ Patients without a clear and direct link to the earthquake or with uncertain origins of their injuries were not included in the study. In light of the seismic event on February 6th, a three-week observation window was strategically chosen. This decision ensured the inclusion of both immediate trauma cases, which commonly surge post-disaster, and the potential delayed presentations due to entrapment or other access barriers. Given the proximity of the two seismic events (separated by just 9 h), it’s challenging to attribute injuries to one specific quake. Every patient included in the study was injured by the earthquake, regardless of whether they were trapped under debris or not. Inclusion criteria mandated that participants must have sustained isolated blunt thoracic trauma with a direct causative link to the earthquake incidents. The term “isolated” is explicitly employed to denote that the thoracic injury was the singular predominant medical concern, devoid of concurrent significant injuries in alternative anatomical regions. Conversely, exclusion criteria encompassed individuals who, upon initial assessment, were discharged absent of requisite imaging evaluations, specifically those possessing a Nexus chest decision instrument score of 0, indicative of a negligible probability of substantial thoracic injury, thereby rendering additional diagnostic evaluations superfluous [ ]. Additional exclusion parameters incorporated individuals manifesting multiple traumas extending beyond isolated thoracic injuries and those with incomplete or inaccessible medical documentation.

The study’s design primarily encompassed the evaluation of individuals who successfully reached and presented to the emergency department subsequent to the earthquake’s aftermath. This approach, while comprehensive in its assessment of hospital-presenting cases, inherently means that there exists a segment of affected individuals who, due to a spectrum of circumstances, did not make it to the hospital setting and are therefore not represented within this dataset.

Prior to the study, institutional permission and ethical approval were obtained from the ethics committee, in accordance with the principles outlined in the Helsinki Declaration. The approval was granted on April XX, 2023, and assigned the reference number XX.

2.2

Study protocol

Data on age, gender, radiological imaging to determine thoracic injuries, medical (necessity of oxygen supplement, or mechanical ventilation requirement), and surgical treatments (tube thoracostomy or thoracotomy) received for thoracic injuries, the department where the patient was followed up in the hospital, and the duration of hospital stay were examined and obtained from electronic medical records.

Thoracic injury sites of the patients and the presence of pathologies such as rib fracture, lung contusion, pneumothorax, hemothorax, and pneumomediastinum were examined by non-contrast thorax computed tomography (CT). In this study, the assessment of trauma severity was based on the Chest Trauma Score (CTS), with patients categorized as having ‘severe’ thoracic trauma if their CTS score was ≥5, in accordance with insights from a retrospective study of the CTS system, which demonstrated that a CTS score of ≥5 was indicative of a heightened likelihood of a poor clinical outcome [ ]. Conversely, patients with a CTS score of <5 were categorized as having ‘mild’ thoracic trauma. In order to calculate the CTS, CT images of the thorax were obtained from the Picture Archiving and Communication System (PACS).There are four different components in the CTS, each with an assigned point value: age (<45 years = 1, 45–65 = 2, >65 = 3); pulmonary contusion (none = 0, unilateral minor = 1, bilateral minor = 2, unilateral major = 3, bilateral major = 4); the number of rib fracture (<3 = 1, 3–5 = 2, >5 = 3); and the presence of bilateral rib fracture = 2. Scores have been assigned to each parameter and the final score was calculated by adding them together. The final CTS could range from 2 to 12. Table 1 shows the calculation of the CTS. (See Fig. 1 .)

Patient flowchart.

2.3

Statistical analysis

Statistical analysis was performed using the Statistical Package for the Social Sciences for Windows (SPSS v.29, Chicago, IL, USA) software. In the context of this investigation, univariate analyses were employed as they provide a clear and concise understanding of relationships within the available data. This methodological choice was informed by both the sample size and the specific characteristics of the dataset. While multivariable analyses offer a deeper understanding of inter-variable relationships, the data constraints in this study guided our analytical approach to ensure the integrity and clarity of our findings. While it was considered that some patients with thoracic injuries due to the earthquake could not be reached, only patients with complete data on all variables were analyzed, and no analyses to address missing data were conducted. The normal distribution of the groups was assessed using histograms and the Shapiro-Wilk test. Descriptive statistics were used to summarize the data, presenting categorical variables as counts and percentages, and continuous variables as mean ± standard deviation or median (interquartile range [IQR], 25th- 75th percentile). Categorical variable comparisons between the two groups employed the chi-square test and, where applicable, Fisher’s exact test. Continuous variable comparisons between these groups utilized the Student’s t -test for normally distributed data and the Mann-Whitney U test for data that wasn’t normally distributed. Statistical significance was determined at a p -value of <0.05, with all analyses employing a two-tailed approach.