Distinct Five-Year Latent Class Trajectories and Predictors of Functional Cognitive Independence Following Traumatic Brain Injury: A TBI Model Systems Study

Early prediction of short- and long-term health outcomes remains a significant medical challenge for clinicians providing care for the traumatic brain injury (TBI) population. In the context of an acute trauma care center, accurate and early prediction of patient outcomes from discharge is critical to better plan for services required by patients with TBI. We aimed to identify the heterogeneous longitudinal recovery trajectories of functional cognitive independence during 5 years post-injury and reveal the demographic, clinical, and injury-related factors associated with trajectory membership. Functional Independence Measure for Cognition (FIM-Cog) was evaluated among Traumatic Brain Injury Model Systems participants diagnosed with a TBI between 1987 and 2024 from discharge, 1, 2, and 5 years post-injury. Latent class growth analysis (LCGA) classified 8060 participants into clusters of FIM-Cog trajectories over 5 years post-injury by fitting 1–7 model solutions and using maximum probability rule to estimate cluster membership. Backward stepwise multinomial logistic regression identified factors associated with trajectory membership. Statistical significance was determined at p < 0.05, two-tailed. A five-class model solution revealed five clusters of trajectories characterized as high independence ( n = 6060, 75.19%), improved independence ( n = 1576, 19.55%), delayed dependence ( n = 60, 0.74%), delayed independence ( n = 284, 3.52%), and low independence ( n = 80, 1.00%). Factors associated with delayed dependence included longer acute stays (odds ratio [OR] = 3.133; 95% confidence interval [CI]: 2.39–4.11), a greater number of injuries before age 15 (OR = 2.066; 95% CI: 1.05–4.06), wider therapeutic windows (OR = 1.060; 95% CI: 1.04–1.08), and lesser same-age injuries (OR = 0.314; 95% CI: 0.10–0.95). Factors associated with low independence included longer acute stays (OR = 2.583; 95% CI: 1.90–3.51), narrower therapeutic windows (OR = 1.035; 95% CI: 1.02–1.05), a greater number of moderate-to severe injuries (OR = 2.120; 95% CI: 1.83–2.89) and same-age injuries in their lifetime (OR = 8.687; 95% CI: 1.28–58.79). Leveraging LCGA revealed five distinct trajectories of functional cognitive independence during 5 years post-injury. Understanding these risk factors during acute care can inform prevention initiatives for optimizing functional cognitive independence during recovery.