B – 59 Exploring Sex as a Moderator for the Relationship Between Age at the Time of Injury and Functional Impairment upon Admission for Rehabilitation of Survivors of Acquired Brain Injury

Abstract Objective Age at injury consistently predicts recovery, with older individuals showing worse outcomes. Given sex differences in biological aging (e.g., hormonal shifts, cardiovascular health), sex may moderate this relationship. This study examines whether sex impacts the link between age at injury and functional impairment at admission to rehabilitation. Method A retrospective record review was conducted for 380 individuals admitted to a brain injury rehabilitation facility. Functional impairment at admission was assessed via staff-rated scores from the Disability Rating Scale, Mayo-Portland Adaptability Inventory-4, and Northwick Park Dependency Scale. Structural equation modeling (SEM) examined whether age, sex, or their interaction predicted impairment. The model showed excellent fit (CFI = 1.00, RMSEA = .02) using maximum likelihood estimation. A latent variable representing functional impairment was defined by disability, dependency, and poor adaptability indicators. Results Our findings indicate that at time of admission, age at injury and sex did not demonstrate a significant relationship with functional impairment, nor did sex significantly moderate this association. Conclusion Early functional impairment did not differ by age or sex in this sample. These associations may emerge later as psychosocial factors begin to outweigh acute biological mechanisms. Admission criteria may have contributed to sample homogeneity, potentially masking differences present in broader populations. Standardized approaches may suffice at admission, but individualized treatment could become more impactful as recovery progresses and demographic factors gain influence. Longitudinal studies are needed to assess whether sex- and age-related differences emerge during later rehabilitation or community reintegration.