Functional independence trajectories over 5 years in older veterans with traumatic brain injury: A model systems study.

Abstract

Background: Research on older adults who sustain a traumatic brain injury (TBI) has predominantly been on civilian, nonveteran populations. Military populations experience higher rates of TBI and often experience the additive effects of TBI and other comorbid disorders, including posttraumatic stress disorder and/or substance use that may increase disability over time.

Objective: To investigate predictors of functional independence trajectories over the 5 years after TBI in veterans 55 years or older at injury.

Setting: Five Veterans Affairs (VA) polytrauma rehabilitation center (PRC) inpatient rehabilitation programs.

Participants: Veterans who experienced their TBI at 55 years or older and had completed one or more Functional Independence Measure (FIM) Motor and Cognitive measure at 1, 2, or 5 years after TBI (n = 184) from the VA TBI Model Systems national database.

Design: Retrospective analysis of observational data using hierarchical linear models.

Main measures: FIM Motor and Cognitive scores at 1, 2, and 5 years after TBI.

Results: Motor and cognitive functioning decreased over time. Lower FIM Motor trajectories occurred in participants who had pre-TBI functional limitations in going out of the home and with longer posttraumatic amnesia (PTA). FIM Motor scores decreased over time, and the decrease was steeper for those with a moderate or severe injury. Lower FIM Cognitive trajectories occurred in participants who had problematic substance use at baseline and among those with longer PTA. FIM Cognitive scores decreased at a steeper rate for participants with greater injury severity.

Conclusions: Similar to previously published studies in civilian populations, older veterans with TBI may be at risk for functional and cognitive decline. This study's findings increase the field's understanding of functional trajectories after TBI in older adults and may help identifty those who are at risk for lower functional outcomes.