Although falls are the most important cause of intracranial hemorrhage in the population over 65, studies have shown that bleeding occurs in only 5% of geriatric patients who fall. Guidelines have been developed to assist the clinician in identifying patients at risk of intracranial hemorrhage due to the relatively low incidence but significant morbidity and mortality. The 'Falls Decision Rule' was developed by de Wit et al. in 2023 to assess the need for CT in this patient group. In this study, external validation of this newly developed score was planned to evaluate its safety, applicability, and authenticity.

In the geriatric population (≥65 years), falls are responsible for 70% of traumatic brain injury. Computed tomography (CT) evaluation of the brain used in evaluating these patients makes it possible to detect intracranial hemorrhage in the early period. Thus, it plays a critical role in initiating timely and necessary interventions. These interventions include blood pressure control, hemorrhage control, and neurosurgical interventions.

Although the most important cause of intracranial hemorrhage in this population is falls, studies have shown that bleeding occurs in only 5% of geriatric patients who fall. Therefore, it is inefficient and costly to perform brain CT evaluation in every patient.

Rules have been developed to assist the clinician in identifying patients at risk of intracranial hemorrhage, which has a relatively low incidence but significant morbidity and mortality. The Canadian Brain CT rule, one of the most widely used rules for this purpose, determines the need for brain CT in patients with head trauma. However, this rule applies to patients with disorientation, amnesia, or loss of consciousness. There are insufficient studies to guide neuroimaging for older adults who hit their heads while falling but do not experience these symptoms. In addition, guidance from the literature for older adults who fall but cannot describe what happened or did not hit their heads is also insufficient. The 'Falls Decision Rule' was developed by de Wit et al. in 2023 to assess the need for CT in this patient group. This criterion was developed by including a total of 4308 patients in the United States and Canadian emergency departments. It suggests that in patients in the geriatric population, there is no need for Brain CT in the absence of significant head trauma due to falls, no memory loss due to falls, no newly developing neurological examination disorder, and a clinical frailty score of less than 5. The sensitivity of this score to exclude clinically significant bleeding is 98.6% (95% CI 94.9-99.6), and the negative predictive value is 99.8% (95% CI 99.2-99.8).

This newly developed rule was developed only in a specific geographical region. In this study, external validation of this newly developed score was planned in order to evaluate its safety, applicability, and accuracy.

Patients over 65 years of age who come to the emergency department with a fall will be observationally recorded on the case form after obtaining consent from the patient or his/her relatives and will be followed up for clinically significant intracranial hemorrhage within 42 days. This study is a validation study, and the protocol used in the original study will be followed. The study is a prospective observational study. The study will start after ethics committee approval and will be conducted at Marmara University Pendik Training and Research Hospital. The data collection process will be completed when the targeted sample size is reached.

The sample size was calculated for the diagnostic value study planned to validate the fall decision rule developed by de Wit et al. to rule out patients with intracranial hemorrhage. Using the incidence, sensitivity, and specificity values shared by the authors as a reference, the minimum sample size to be included in the study was calculated as 663, with 80% power and 0.05% margin of error. Considering the risk of missing and inaccurate measurements, the target sample size was increased by 15% and set as 763.

Data will be obtained from patient files, Hospital Information Management System, and PACS systems; Demographic information (age, gender), Known diseases (HT, DM, AF, CHF, etc.), Information on falls, Physical examination information), Consultation notes, if any, Antiplatelet, anticoagulant use, Frailty score, The CT scan results will be saved.

Patients will be followed up for delayed intracranial hemorrhage within 42 days after the fall as in the original study. Also as in the methodology of the original study, patients will be followed up through the electronic information system. Previous studies have shown that this method has a low sensitivity (37%, 95% CI 21-56) for intracranial hemorrhage when patients are questioned for intracranial hemorrhage by telephone call. Therefore, in the original study and this study, it was planned to follow up the information of the patients from the electronic information system records instead of telephoning. The intracranial hemorrhage status of the patients within 42 days will be followed up through the hospital information system and patient information system.

Inclusion Criteria:

• Patients aged 65 years and older.
• Patients who presented to the emergency department within 48 hours of a fall.
• Patients who provided informed consent to participate in the study or whose legal guardians provided consent if the patients are unable to do so.

Exclusion Criteria:

• Patients who have already been included in the study previously.
• Patients who refuse medical treatment or withdraw consent during the study period.
• Patients with incomplete data necessary for the study.

The study population consists of geriatric patients aged 65 years and older who present to the emergency department within 48 hours of experiencing a fall on level ground ((either inside or outside), off a chair, toilet seat, or out of bed). These patients will be included if they provide informed consent or if their legal guardians provide consent if the patients are unable to do so. The study aims to externally validate the Falls Decision Rule to exclude intracranial bleeding in this specific population. All patients meeting the inclusion criteria and none of the exclusion criteria will be enrolled in the study, and they will be observed for clinically significant intracranial bleeding for up to 42 days post-fall.

Deaths assessed through 42 days

Since this is an observational study, no direct interventions or experimental treatments were applied to the participants. Therefore, the likelihood of observing adverse events directly related to the study itself is nonexistent. Only all-cause mortality was assessed through 42 days.

This study has limitations, primarily its single-center design, which may limit generalizability. However, as an external validation study, the findings suggest applicability to broader populations. Variability in physician judgment on CT use is another limitation, despite standardized training. Not all patients underwent CT at the initial visit, posing a risk of missed CIIB. However, a 42-day follow-up ensured comprehensive assessment, with no patients lost to follow-up.