Traumatic brain injury: Clinical patterns and predictive factors in a rural hospital setting

INTRODUCTION

Traumatic brain injury (TBI) is a condition resulting from external force affecting the scalp, skull, facial bones, or brain, causing a disruption in brain function or other evidence of brain pathology, ranging in severity from mild to life-threatening injuries.^[1,2] It is caused by a traumatic process, which includes both blunt or sharp trauma and can be accompanied by or without intracranial bleeding.^[1] It is a major cause of disability and mortality globally among all trauma-related injuries, with an estimated 69 million individuals affected annually, regardless of any age group.^[3] Apart from the effects on individuals, this injury causes disability for their families and represents a burden to healthcare systems due to high healthcare costs.^[4]

Over 1.2 million people die annually on the world’s roads, according to the World Health Organization. More than 90% of global road traffic deaths happen in low- and middle-income nations, even though these countries account for just 48% of the world’s vehicles.^[5] In Indonesia, TBI remains a leading cause of emergency visits and mortality, with road traffic accidents, especially motorcycle-related injuries, being the most frequent mechanism of injury. The burden is especially higher in provinces such as Bali, where motorcycle use is high. A hospital-based study in a main referral hospital center in Bojonegoro, East Java, reported 800 patients with TBI often linked to road accidents.^[6] Similarly, a study from Sanglah Hospital in Bali with 525 samples mostly aged 19–40 years highlighted that the majority of TBI cases were associated with traffic accidents.^[7] However, there is limited epidemiological data on TBI,^[1] especially from district-level hospitals in rural or semi-urban areas, including Bangli Regency.

Despite the availability of studies in major referral centers, data on hospitals at the district level in Indonesia are scarce. The lack of localized data can affect the development of region-specific protocols and efficient referral systems. This study aims to describe the clinical characteristics of patients with TBI admitted to Bangli General Hospital, Bali, Indonesia, thus enhancing understanding of the distribution and severity of TBI in a district hospital setting. Furthermore, it aims to identify clinical factors associated with patient outcomes.

MATERIALS AND METHODS

This retrospective cohort study was conducted at Bangli General Hospital, Bali, Indonesia, from January 2023 to April 2025. A total sampling method was used to include all patients diagnosed with TBI recorded in the medical records. Patients were included if they were diagnosed with TBI based on the International Classification of Disease 10 codes as follows: S06.0 (concussion), S06.1 (traumatic cerebral edema), S06.2 (diffuse TBI), S06.3 (focal TBI), S06.4 (epidural hemorrhage), S06.5 (traumatic subdural hemorrhage), S06.6 (traumatic subarachnoid hemorrhage [SAH]), S06.7 (intracranial injury with prolonged coma), S06.8 (other specified intracranial injuries), S06.9 (unspecified intracranial injury), S02.0 (fracture of vault of skull), S02.1 (fracture of base of skull), and S01.9 (open wound of head, part unspecified). All patients were included regardless of isolated head trauma or with additional multiple traumas elsewhere. We excluded patients with incomplete medical records and patients under the age of 5 years. Children under 5 years were excluded to ensure consistency in consciousness testing, as the usual Glasgow Coma Scale (GCS) lacks full validation for this age range. The pediatric GCS necessitates distinct interpretation, which was not consistently reflected in our hospital records, and enrolling these individuals may have resulted in misclassification bias. Consequently, a distinct analysis specialized to pediatrics was not practicable in this investigation. The Ethics Committee has approved this study with an ethical clearance number of 400.7.22.2/869/ RSUD.

The variables collected included demographic data (age, sex, and comorbidities), GCS score, clinical information related to TBI, blood pressure, therapeutic interventions, length of stay, and patient outcomes. All variables were then categorized. Age was then classified into children (5–9 years), adolescents (10–18 years), adults (19–45 years), pre-elderly (46–65 years), and elderly (>65 years). The GCS score was used to classify the severity of TBI into mild (GCS 13–15), moderate (GCS 9–12), and severe TBI (GCS 3–8). Clinical information related to TBI is the cause of injury, history of loss of consciousness (LOC), duration of LOC, type of trauma, number of bleeding types, presence and type of skull fracture, and the time interval between the injury and arrival at the hospital. The number of bleeding types was categorized based on computed tomography (CT) findings documented in medical records. The forms of hemorrhage encompassed subdural hematoma (SDH), epidural hematoma (EDH), subarachnoid hemorrhage (SAH), and intracerebral contusion. Each unique category was enumerated, and patients were classified into no bleeding, one type, two types, three types, or more than three types. Combinations were derived from simultaneous observations in a single CT scan (e.g., SDH + SAH = two kinds). This classification was established retroactively based on radiology reports instead of re-evaluated images. Blood pressure was taken when came to the emergency room and was categorized into four groups, including hypotension (systolic blood pressure [SBP] < 90 mmHg or diastolic blood pressure [DBP] < 60 mmHg), normal (SBP < 150 mmHg or DBP < 90 mmHg), grade 1 hypertension (SBP > 140 or DBP > 90), and grade 2 hypertension (SBP > 160 or DBP > 100). Therapeutic interventions included conservative treatment and operative treatment. Operative management was not randomized but based on clinical judgment by the attending neurosurgeon. Indications included large intracranial hematomas, depressed skull fractures, or deteriorating neurological status. All surgeries were performed in-house at Bangli General Hospital; patients requiring advanced neurosurgical procedures beyond local capacity were referred to a tertiary center and excluded from operative analysis.

The outcome was defined as in-hospital mortality during the initial admission. Patients referred to higher-level facilities or discharged against medical advice were excluded from the death count due to the lack of systematic availability of post-transfer or post-discharge outcomes. No organized follow-up system was in place following hospitalization, potentially leading to an underestimation of total death rates.

Statistical analysis was done using IBM Statistical Package for the Social Sciences (SPSS) version 29.0 (IBM Corp., Armonk, NY, USA). Qualitative data were presented as frequencies and percentages. Bivariate analysis of dichotomous variables was done using the Chi-square test or Fisher’s exact test, depending on the presence of expected cell count below five. Variables with more than two categories were analyzed with the Pearson Chi-square test. Significant variables on univariate analysis were then included in the multivariate analysis to look for independent factors associated with outcomes in TBI.

RESULTS

DISCUSSION

Our study reported the clinical patterns and predictors of in-hospital mortality among TBI patients treated at Bangli General Hospital. The reported in-hospital mortality rates for TBI vary across studies. This study found an overall mortality of 4.8%, which is lower than reports from several low- and middle-income countries (LMIC), but higher than some high-income countries. A study in Bangladesh reported a mortality rate of 10.3%^[8] while a study of 483 respondents in Ethiopia recorded 120 deaths (24.8%), showing a higher mortality rate compared to ours. On the other hand, high-income settings, such as the United States, showed lower rates with a 2% death rate, and the majority had mild TBI.^[9] Taken together, these comparisons highlight the global disparity of TBI outcomes, where limited resources in low- and middle-income countries are consistently associated with higher mortality rates, further supporting the observation that road traffic-related TBI remains disproportionately higher in such regions. This further supports that low and middle-income countries had higher road traffic deaths.^[5]

The majority of patients with TBI are males, primarily adults between the ages of 19 and 45 years. This finding is in accordance with other studies conducted in Indonesia that also discovered a predominance of male patients in TBI.^[1,6,7] This might be explained by higher activity, the absence of protective gear, and a tendency to be less cautious while riding.^[1] While male predominance is consistent across most trauma populations, our findings confirm that sex itself does not significantly influence outcomes. However, a study by Niryana et al. also found that gender is not associated with outcome, similar to our study.^[7] Age was a significant factor in TBI outcomes even after multivariate analysis, as mortality is higher in older people, which is consistent with another study.^[10] A study highlighted that age significantly affects mortality and morbidity, with poorer outcomes becoming more likely as age increases, particularly beyond 40 years.^[11] This may be attributed to the brain’s reduced ability to recover with age, as the number of functioning declines and cumulative exposure to minor, often undetected, injuries increases.^[12] Thus, age emerges as one of the strongest and most consistent predictors of TBI outcomes across different populations, including ours.

Traffic accidents were the most common cause of TBI, with various mechanisms of accidents such as collisions between motor vehicles, single-vehicle crashes, bicycle falls, and pedestrians getting hit by, or falling from, the passenger seats. This aligns with findings from previous studies, including those in Indonesia.^[1,6,7] In Indonesia, traffic accidents are more frequent in urban regions (43.1%) compared to rural areas (28.2%). One study reported that motor vehicle crashes accounted for 5.4% of TBI cases among adolescents and were the leading cause of traffic-related injury in Indonesia. This is mainly because motorcycles are the preferred mode of transportation in Indonesia.^[1,6] It is important to note that Indonesian traffic law mandates motorcycle helmet use and seatbelts for car passengers; however, compliance remains inconsistent, especially in rural or semi-urban areas such as Bangli. Protective vests are not mandatory, and enforcement of safety measures is variable. The national speed limits are generally set at 50 km/h in urban areas and 80–100 km/h on intercity roads, but these are often exceeded. These contextual factors help explain the high proportion of traffic-related TBI in Indonesia, and comparison with countries that have stricter enforcement of helmet use and speed control (such as many high-income nations) highlights the role of regulatory compliance in reducing TBI incidence and severity. Our data, therefore, not only reflect local patterns but also emphasize the urgent need for preventive strategies such as stricter helmet enforcement and improved road safety regulations.

Our study showed that multiple traumas are independently associated with death. Another study found that the mortality rate of patients with isolated head injuries is about 20–30%, whereas it can reach over 40% in multiple traumas with head injury. This is likely due to the presence of additional emergencies due to other trauma. One study found that the major cause of death in patients with multiple traumas with head injury was the presence of hypovolemic shock.^[13] However, another study found that polytrauma is not independently associated with the prognosis of TBI patients but is associated with earlier mortality. Coagulopathy and physiological instability are more critical factors in determining mortality.^[14] The differences can be explained as the latter study included only moderate-to-severe TBI patients, whereas our study mostly consisted of mild TBI patients. This indicates that the prognostic impact of polytrauma is context-dependent, influenced both by case mix and severity distribution within the study population.

Hospital-based studies consistently show that mild TBI (GCS 13–15) accounts for the majority of cases, while severe TBI (GCS ≤ 8) constitutes a smaller percentage, as observed in this study. For example, an Indonesian tertiary hospital’s emergency series found that 74.5% of TBI cases were mild, and only 5.3% were severe cases.^[15] Likewise, other studies in Bali reported that more than half the TBI cases in their respective hospitals were mild (GCS 13/14–15).^[1,7] However, GCS is an independent factor associated with death in TBI patients. GCS severity is significantly associated with worse outcomes after adjusting for multiple variables. This is supported by a study in Bangladesh, in which severe GCS (<8) raised the odds of death by 8-fold.^[8] Another study found that severe TBI with an initial GCS of 3–5 had high mortality, poor functional outcomes, and disability rates at long-term assessment.^[16] Our findings reinforce the role of GCS as a simple but robust prognostic tool, even in district-level hospitals where advanced neuromonitoring may not be available.

Most of the patients experienced LOC with a duration of 0–10 min. LOC at the time of injury, particularly prolonged LOC, is an indicator of significant brain trauma. Unconsciousness signals damage to the ascending reticular activating system or cerebral hemispheres. It reflects either diffuse brain injury or ongoing intracranial pathology.^[1,17] However, further analysis revealed that none of these factors are independent predictors of death in TBI patients in this study. This suggests that although LOC remains a useful clinical sign of brain dysfunction, its prognostic value is overshadowed by stronger predictors such as GCS and radiological findings.

TBI can be with or without traumatic intracranial hemorrhage, as most of the patients in this study had no bleeding, similar to another study. The presence of hemorrhage, such as SDH, EDH, SAH, or intracerebral contusions, is independently associated with worse outcomes, especially those with more than three types of bleeding.^[1] The presence of a skull fracture is an independent factor affecting TBI outcome in this study. Another cohort study found that skull factor was a significant independent risk after adjustment for other cofounding factors such as age, comorbidities, and injury severity.^[18] Simulation studies suggest that while fractures might lower the likelihood of diffuse brain injuries, they may simultaneously raise the chance of brain contusions.^[19] Researchers found that skull fractures are linked to poorer outcomes in cases of moderate and severe TBI and increase the risk of cerebrospinal fluid leakage. Furthermore, fractures are frequently associated with both localized and widespread brain damage, such as cranial nerve injuries, seizures, and various forms of intracranial bleeding. Patients who sustain skull fractures also appear more likely to experience neurological complications compared to those without such injuries.^[18] Our results support this evidence, highlighting that skull fractures and intracranial bleeding patterns should be prioritized in prognostic evaluation and early management decisions.

We found that hypotension is uncommon in TBI, as supported by another study.^[15] Hypotension is relatively less common in TBI because isolated intracranial bleeding typically is not sufficient to cause shock.^[20] The presence of hypotension usually indicates extensive blood loss or multi-trauma. Thus, when it occurs, it signifies a worse prognosis.^[21] We found that the length of hospital stay also affects TBI outcome on bivariate analysis. However, both factors (blood pressure and LOS) are not independent, as both were influenced by many other factors, such as TBI severity (GCS). The length of hospital stay tends to reflect injury severity and complications. Mild TBI patients often have shorter stays, whereas severe TBI can require weeks of hospitalization. This study primarily consists of mild TBI, and more than half of the patients stayed for 1–3 days. Similar to another study in Indonesia consisting of mostly mild TBI, over half of the patients were discharged home directly from the emergency department, and only about one-third were admitted to the hospital.^[15] These findings indicate that blood pressure and length of stay may serve as indirect markers of injury severity rather than independent prognostic determinants.

On the other hand, TBI may occur with or without traumatic intracranial hemorrhage, since the majority of patients in this study had no bleeding, akin to findings in another investigation. The occurrence of hemorrhage, including SDH, EDH, SAH, or intracerebral contusions, is independently correlated with poorer outcomes, particularly in cases with more than three forms of bleeding. EDH affecting the posterior fossa or spanning both supra- and infratentorial compartments poses distinct surgical problems. The restricted structure of the posterior fossa heightens the likelihood of fast neurological decline, whereas multi-compartmental EDHs necessitate meticulous surgical planning. Recent literature has delineated particular techniques for these intricate instances, including a combination draining technique for simultaneous supra- and infratentorial EDHs.^[22] Such reports are particularly pertinent in low-resource environments like ours, because postponed referrals to tertiary hospitals may hinder prompt intervention.

This study has several limitations that should be considered when interpreting the results. The retrospective nature of the study carries a risk of selection bias and depends heavily on the accuracy and completeness of medical records. We tried to mitigate the risk of bias using a total sampling method. However, we exclude children under 5 years of age to maintain clinical standard assessment, but this may limit our understanding of TBI outcomes in younger children. Second, this study is conducted at a single district-level hospital in Bali, which may not be generally applicable to larger referral centers or hospitals.

The small proportion of surgical cases reflects both the predominance of mild TBI in our cohort and the selective indications for operative intervention. Since surgical decision-making was based on clinical judgment and resources available at a district hospital, our findings should not be interpreted as equivalent to randomized comparisons. Another limitation is that our outcome measure was restricted to in-hospital mortality. Because most patients had short hospital stays (1–3 days), deaths occurring after referral or after discharge against medical advice could not be captured. This likely results in an underestimation of true TBI-related mortality in this population. Future research incorporating multi-center data and a prospective design with functional outcome assessment will be essential to validate and expand these findings.

CONCLUSION

This study highlights the clinical profile and factors associated with TBI outcomes in a district-level hospital setting in Bangli General Hospital. TBIs were mostly caused by traffic accidents, predominantly affecting males aged 19– 45 years. The majority arrived at the hospital within 0–1 h after the injury, presenting with normal blood pressure, mild TBI, isolated head trauma, and brief LOC, which lasted around 0–10 min. Most patients did not have intracranial hemorrhage or skull fractures and had a short length of stay (1–3 days). These patients were treated conservatively. Several factors, such as age, GCS, type of trauma, number of bleedings, and the presence of skull fracture, were significantly associated with patients’ mortality, and early recognition of these factors can help optimize outcomes. While these predictors are important for early risk stratification in district hospitals, the retrospective, single-center design limits wider generalizability. Future multicenter prospective studies with long-term follow-up are needed.