Factors Associated with a Disposition-Based Indicator of Severe Injury Among Older Adults with Fall-Related Injuries: A Secondary Analysis of the 2023 Emergency Department-Based Injury In-Depth Surveillance

Background/Objectives: Falls are a major cause of injury-related morbidity and mortality among older adults. This study aimed to examine factors associated with a disposition-based indicator of severe injury among older adults with fall-related injuries using data from the 2023 Emergency Department-based Injury In-depth Surveillance. Methods: This secondary analysis used data from the 2023 Emergency Department-based Injury In-depth Surveillance conducted by the Korea Disease Control and Prevention Agency. A total of 24,632 adults aged ≥65 years with fall-related injuries were included. The primary outcome was a disposition-based indicator of severe injury, defined as hospital admission, transfer to a higher-level hospital, or death. Multivariable logistic regression was performed, and sensitivity analyses were performed using alternative disposition-based outcomes, Revised Trauma Score (RTS)-based physiological severity, and the original four AVPU categories. Results: Of 24,632 participants, 9248 (37.5%) met the criteria for the primary outcome. Older age, falls from a height, outdoor injuries, emergency transportation, and impaired consciousness were associated with higher odds of the primary outcome, whereas alcohol use at the time of injury, stair-related falls, injuries in road or traffic areas or commercial or public facilities, sports or leisure activities, other activities, and nighttime injuries were associated with lower odds. Emergency transportation and impaired consciousness were strongly associated with the outcome. Emergency transportation remained consistently associated across sensitivity analyses, whereas worsening AVPU levels showed progressively higher odds. Conclusions: Several patient, injury-related, and clinical characteristics were associated with the disposition-based indicator of severe injury. Variation across alternative outcome definitions highlights the importance of distinguishing between emergency department disposition and physiological injury severity.