Usefulness of the BIG Score in Predicting Massive Transfusion and In-Hospital Death in Adult Trauma Patients

The base deficit (B), international normalized ratio (I), and Glasgow coma scale (GCS) (BIG) score is useful in predicting mortality in pediatric trauma patients; however, studies on the use of BIG score in adult patients with trauma are sparse. In addition, studies on the correlation between the BIG score and massive transfusion (MT) have not yet been conducted. This study aimed to evaluate the predictive value of BIG score for mortality and the need for MT in adult trauma patients. This retrospective study used data collected between 2016 and 2020 at our hospital's trauma center and registry. The predictive value of BIG score was compared with that of the Injury Severity Score (ISS) and Revised Trauma Score (RTS). Logistic regression analysis was carried out to assess whether BIG score was an independent risk factor. Receiver operating characteristic (ROC) curve analysis was performed, and predictive values were evaluated by measuring the area under the ROC curve (AUROC). In total, 5,605 patients were included in this study. In logistic regression analysis, BIG score was independently associated with in-hospital mortality (odds ratio (OR): 1.1859; 95% confidence interval (CI): 1.1636–1.2086) and MT (OR: 1.0802; 95% CI: 1.0609–1.0999). The AUROCs of BIG score for in-hospital mortality and MT were 0.852 (0.842–0.861) and 0.848 (0.838–0.857), respectively. Contrastingly, the AUROCs of ISS and RTS for in-hospital mortality were 0.795 (0.784–0.805) and 0.859 (0.850–0.868), respectively. Moreover, AUROCs of ISS and RTS for MT were 0.812 (0.802–0.822) and 0.838 (0.828–0.848), respectively. The predictive value of BIG score for mortality and MT was significantly higher than that of the ISS. The BIG score also showed a better AUROC for predicting in-hospital mortality compared with RTS. In conclusion, the BIG score is a useful indicator for predicting mortality and the need for MT in adult trauma patients.


Introduction
Injuries represent a major public health concern, contributing signifcantly to morbidity and mortality worldwide [1].Te global burden of traumatic injuries is evident, with approximately 40 million people experiencing trauma annually in the United States alone and 6 million deaths reported worldwide [2].In South Korea, the impact of traumatic injuries is no less alarming, as evidenced by the 2021 statistics results from the Korean Trauma Data Bank (KTDB), revealing 1,602 deaths among 8,906 severe trauma patients [3].Te severity of traumatic injuries necessitates the development of reliable tools and indicators to assess prognosis and guide treatment decisions for such patients [4].
Among the various scoring systems, the base defcit (BD), international normalized ratio (INR), and Glasgow coma scale (GCS) (BIG) score, which is derived from three key indicators known to infuence the survival outcomes of trauma patients [5], have emerged as a promising tool because of its simplicity and clinical applicability.Te BIG score has demonstrated utility in predicting outcomes among pediatric trauma patients.In addition, previous studies have demonstrated the encouraging results on the use of BIG score in predicting mortality in adult trauma patients when compared with those of other trauma assessment indicators [6,7].However, the literature on the use of BIG score for adult trauma patients remains relatively scarce, with only a limited number of studies addressing this topic.Moreover, studies assessing the correlation between the BIG score and massive transfusion (MT) have not yet been conducted.
Terefore, the primary objective of this study was to assess the predictive value of BIG score for mortality rates in adult trauma patients.Te second objective of this study was to evaluate the predictive power of BIG score for MT in adult trauma patients.We hypothesized that the BIG score will serve as a valuable prognostic tool for predicting mortality and MT in adult trauma patients.

Materials and Methods
Tis was a retrospective single-center study conducted in a trauma center of a tertiary care university hospital.Te hospital operates a separate emergency department within the trauma center, which is equivalent to a grade A trauma center representing the southeastern region of South Korea.Approximately, 1,000 severe trauma patients present at the trauma center annually.Tis study was approved by the Institutional Review Board (IRB) of our hospital (IRB 2306-003-127) and conducted in accordance with the relevant guidelines.
Tis study included patients who presented to the emergency department of the trauma center between 2016 and 2020.Te exclusion criteria were as follows: (a) age <16 years, (b) cardiac arrest when admitted to the trauma center, and (c) missing values for the BIG score component, MT, and mortality.
Data were extracted from the KTDB and electronic medical records of the hospital.KTDB is a statistic data published annually by the National Emergency Medical Center in Korea that provides the basis for a trauma treatment system by collecting information on trauma patients from medical institutions selected as regional trauma centers and providing the information necessary for various studies [3].Te extracted data included age, sex, type of injury, Revised Trauma Score (RTS), MT, Injury Severity Score (ISS), in-hospital GCS score, lactic acid level, prothrombin time (PT)/INR, BD, pH, activated partial thromboplastin time (APTT), BIG score, and aspartate transaminase (AST) and alanine transaminase (ALT) levels.
Te BIG score was calculated using the following formula: BIG score � (BD) +(2.5 × INR) +(15 − GCS). (1) Categorical variables are reported as frequencies (percentages) and continuous variables as medians of the interquartile range.We performed receiver operating characteristic (ROC) analysis to identify the sensitivity, specifcity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) of the BIG score.Predictive value was assessed using the area under the ROC (AUROC) curve.Logistic regression analysis was carried out to determine the independent efect of BIG score on mortality and MT.All tests were two-sided, and P values <0.05 were considered statistically signifcant.MedCalc version 22.007 (MedCalc Software, Ostend, Belgium) was used for the statistical analyses.

Results and Discussion
During the study period, 6,466 patients visited the emergency department of the trauma center.Of these, 861 were excluded: age <16 years, n � 178; cardiac arrest at the time of emergency department visit, n � 509; and missing values, n � 174.Ultimately, 5,605 patients were included in this study (Figure 1) and 4,330 (77.25%) were male.Te mean age of the patients was 58 years (range, 43-68).Among all patients, 521 (9.30%) died and 437 (7.8%) received MT.
We then compared the survival and nonsurvival groups.Te nonsurvival group had a signifcantly lower GCS score (P < 0.001) and higher PT/INR and BD (P < 0.001) than the survival group.Furthermore, the nonsurvival group had a signifcantly lower pH (P < 0.001) and higher RTS, ISS, lactic acid level, APTT, and AST/ALT levels (P < 0.001) than the survival group.Te BIG score and MT ratio were signifcantly higher in the nonsurvival group than in the survival group (P < 0.001).Te data are presented in Table 1.
ROC analysis was performed, and AUROC was measured to evaluate the predictive value (Figure 2).AUROCs of BIG score for in-hospital mortality and MT were 0.852 and 0.848, respectively (Table 2).AUROC of BIG score for in-hospital mortality was not signifcantly lower than that for the RTS and signifcantly higher than that for the ISS.In addition, AUROC of BIG score for MT was superior to that for both RTS and ISS.Te sensitivity, specifcity, PPV, NPV, PLR, and NLR of the BIG score, ISS, and RTS are shown in Table 3.To determine whether BIG score was an independent risk factor for inhospital mortality and MT, logistic regression analysis was performed (Table 4).BIG score remained independently associated with in-hospital mortality (odds ratio (OR): 1.1859; 95% confdence interval (CI): 1.1636-1.2086;P < 0.001) and MT (odds ratio (OR): 1.0802; 95% confdence interval (CI): 1.0609-1.0999;P < 0.001) after adjustment for age, sex, and ISS.

Discussion
Tis study aimed to assess the ability of BIG score to predict in-hospital mortality and MT in adult trauma patients and compare its predictive value with that of ISS and RTS.Te Emergency Medicine International fndings of this study demonstrated that the BIG score was an independent risk factor for in-hospital mortality and MT in adult trauma patients.Moreover, the prognostic value of BIG score for mortality and MT was signifcantly higher than that of the ISS, and the BIG score also showed a better AUROC for predicting in-hospital mortality than the RTS.Considered the most well-known pediatric trauma scoring system, the Pediatric Trauma Score consists of six items: weight, systolic blood pressure, external wounds, fractures, airway, and level of consciousness.Another widely used pediatric scoring system, the Pediatric Risk Index, requires 12 parameters [5].Tese scoring tools used for children were greatly complicated, with difculty in identifying results rapidly; thus, a simpler scoring tool was required to predict outcomes in pediatric trauma patients.Te BIG score, introduced in 2010 in war and civilian sectors, eliminates anatomical and hemodynamic parameters.Instead, it utilizes parameters such as the GCS, which is a simple clinical evaluation, and laboratory parameters BE and PT/INR, which can be easily obtained in the emergency department [5].Unlike other scoring tools, such as the ISS, the BIG score does not require variables that are not readily available during the acute phase of injury management.
Te most common cause of death in adult trauma patients is traumatic brain injury, followed by hemorrhage [8,9].GCS is an efective tool for predicting mortality as it represents the severity of traumatic brain injury.Several studies have highlighted the value of GCS as a component of BIG score when evaluating the correlation between the severity of traumatic brain injury and patient outcomes [10,11].GCS is still widely used in trauma care settings and is an important factor in predicting mortality and guiding treatment decisions.Traumatic hemorrhage, the second leading cause of traumatic mortality, causes acidosis and coagulopathy.Te BIG score uses BD to refect shock and acidosis.BD is a valuable predictor of shock, abdominal injury, fuid demand, resuscitation efectiveness, and post-traumatic mortality in trauma patients [12][13][14][15][16][17].In particular, BD, as an independent variable in adult trauma patients, is an efective factor in predicting trauma patient mortality [12,[18][19][20].Te INR component of the BIG score represents the patient's coagulation activity.In trauma patients, coagulopathy can occur owing to an increase in the INR, leading to impaired blood clotting and increased bleeding risk.Te mechanisms underlying coagulopathy can be complex and multifactorial, involving various physiological responses to injury and activation of the coagulation system.Several factors contribute to the increase in INR in trauma patients [21].Accordingly, coagulopathy is an important factor to predict death in trauma patients [14,22].Terefore, the BIG score has a strong predictive power for mortality in trauma patients because it includes parameters that refect the two major causes of acute death from trauma (brain damage and bleeding).
According to our results, the BIG score showed good outcomes in predicting mortality and the need for MT.To     Tis study had several limitations.First, owing to its retrospective nature and the use of registry data, we were unable to identify any potential medical errors that could have infuenced the treatment outcomes.Second, this study was conducted in a single center, which might limit the generalizability of the fndings to patients in other emergency departments.Tird, scores refecting the results of Focused Assessment with Sonography in Trauma, such as the Assessment of Blood Consumption score, were not used in this study because no ultrasound results were available in the trauma center's database.

Conclusions
Te BIG score is a valuable indicator for predicting both mortality and the need for MT in adult trauma patients.Te predictive value of the BIG score surpassed that of the ISS and was comparable to that of the RTS, making it a powerful tool for adult trauma assessment.

Figure 2 :
Figure 2: Receiver operating characteristic curve for in-hospital mortality (a) and massive transfusion (b).

Table 2 :
AUROC for the BIG score, ISS, and RTS regarding in-hospital mortality and MT.
BIG: base defcit, international normalized ratio, and Glasgow coma scale; ISS: Injury Severity Score; RTS: Revised Trauma Score; AUROC: area under the receiver operating characteristics curve.
PPV: positive predictive value; NPV: negative predictive value; PLR: positive likelihood ratio; NLR: negative likelihood ratio; BIG: base defcit, international normalized ratio, and Glasgow coma scale; ISS: Injury Severity Score; RTS: Revised Trauma Score; AUROC: area under the receiver operating characteristics curve.

Table 4 :
Multiple logistic regression analysis for in-hospital mortality and MT.