The Longitudinal Effects of Comorbid Health Burden on Functional Outcomes for Adults With Moderate to Severe Traumatic Brain Injury

Abstract

Objective: To evaluate the impact of physical, mental, and total health condition burden on functional outcome and life satisfaction up to 10 years after moderate to severe traumatic brain injury (TBI).

Setting: Six TBI Model Systems centers.

Participants: Three hundred ninety-three participants in the TBI Model Systems National Database.

Design: Retrospective cohort study.

Main measures: Self-reported physical and mental health conditions at 10 years postinjury. Functional Independence Measure Motor and Cognitive subscales and the Satisfaction With Life Scale measured at 1, 2, 5, and 10 years.

Results: In 10-year longitudinal individual growth curve models adjusted for covariates and inverse probability weighted to account for selection bias, greater physical and mental health comorbidity burden was negatively associated with functional cognition and life satisfaction trajectories. Physical, but not mental, comorbidity burden was negatively associated with functional motor trajectories. Higher total health burden was associated with poorer functional motor and cognitive trajectories and lower life satisfaction.

Conclusions: This study offers evidence that comorbidity burden negatively impacts longitudinal functional and life satisfaction outcomes after TBI. The findings suggest that better identification and treatment of comorbidities may benefit life satisfaction, functional outcome, reduce healthcare costs, and decrease reinjury. Specific guidelines are needed for the management of comorbidities in TBI populations.

Figure 1:

Flow Diagram of Participants in Analytic Sample

Figure 2A-C:

The histogram for physical, mental, and total health burden in plots 2a-c, respectively. The median (IQR) for the three health scores were as follows: A) Physical health score, Median=2 (IQR: 1,3); Mental health score, Median=1 (IQR: 0, 2); Total health score, Median=3 (IQR: 1, 5).

Figure 3:

The following plots represent trajectories for three exemplar cases that exhibited the following demographic and clinical characteristics. A) Case 1: 37 year old, male, white race, not married, less than HS education, employed, 3 days to follow commands, 21 day rehab LOS, 72 FIM Motor rehab discharge, 25 FIM Cognitive at rehab discharge; B) Case 2: 55 year old, black female, married, less than HS education, not employed, 8 days to follow commands, 80 FIM motor, 30 FIM cognitive, 18 day rehab LOS; C) Case 3: 65 year old, Hispanic female, not married, less than HS education, employed, 12 days to follow commands, 78 FIM motor at rehab discharge, 28 FIM cognitive at rehab discharge, 20 day Rehab LOS. We plot 10-year trajectories in four counterfactual scenarios for a given case for three different outcomes (1, 5, 7, and 11 total health conditions).