ABSTRACT
OBJECTIVE: To examine whether ageing with a TBI was associated with a greater burden of health-related comorbidities compared to a non-TBI control cohort, and examine the associations between comorbidity burden, emotional outcomes, and health-related quality of life (HRQoL) after TBI across ages. DESIGN: Cross-sectional. SETTING: Research centre or telephone. PARTICIPANTS: The study included 559 participants (NTBI=291, NControls=268). Participants with TBI were recruited during inpatient rehabilitation and had sustained a moderate-severe TBI 1-33 years previously. Non-TBI controls were a convenience sample recruited through advertisements in the community. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The number of cardiovascular, general physical health, and mental health comorbidities was compared between cohorts and age strata using Poisson regression. The relationships between comorbidities, age, emotional outcomes (Generalized Anxiety Disorder Scale-7, Patient Health Questionnaire-9) and HRQoL (PROMIS Global Health Measure) were examined with linear regression. Distinct subgroups of comorbidities were identified using latent class analysis. Associations between comorbidity classes with demographic and outcome variables were evaluated using multinomial logistic and linear regressions, respectively. RESULTS: TBI participants had a significantly higher comorbidity burden than controls, primarily driven by elevated rates of mental health disorders (RRâ¯=â¯2.71, 95% CI [1.37, 5.35]). Cardiovascular and physical health comorbidities were not elevated in the TBI group compared to controls. Both cohorts had three similar comorbidity subgroups, suggesting consistent patterns of co-occurring health conditions regardless of TBI exposure. Physical and mental health comorbidities were associated with elevated depression and anxiety symptoms and diminished HRQoL after TBI compared to controls. CONCLUSION: TBI was associated with greater mental, but not physical, health comorbidities in the decades following injury. However, physical and mental health comorbidities significantly impacted emotional and HRQoL status after TBI, underscoring a greater need for long-term support for individuals with TBI coping with both physical and mental health comorbidities.
ABSTRACT
Objective: This study examined the relationship between cognitive reserve measured with the Cognitive Reserve Index questionnaire (CRIq) and cognitive and functional outcomes in a chronic traumatic brain injury (TBI) cohort compared to a non-TBI cohort. The utility of the CRIq was compared to common proxies of cognitive reserve (premorbid IQ and years of education) in TBI and non-TBI cohorts. Method: Participants were 105 individuals with moderate-severe TBI (10-33 years post injury) and 91 participants without TBI. Cognitive outcome was examined across four cognitive factors; verbal memory, visual ability and memory, executive attention, and episodic memory. Functional outcome was measured using the Glasgow Outcome Scale Extended. The CRIq total score and three subscale scores (education, work, leisure) were examined. Results: In the TBI cohort, associations were identified between two CRIq subscales and cognitive factors (CRIq education and verbal memory; CRIq work and executive attention). There were no associations between CRIq leisure and cognitive outcomes, or between CRIq and functional outcome. Model selection statistics suggested premorbid IQ and years of education provided a better fit than the CRIq for the relationship between cognitive reserve with two cognitive factors and functional outcome, with neither model providing an improved fit for the remaining two cognitive factors. This finding was broadly consistent in the non-TBI cohort. Conclusion: Cognitive reserve contributes significantly to long-term clinical outcomes following moderate-severe TBI. The relationship between cognitive reserve and long-term cognitive and functional outcomes following TBI is best characterised with traditional proxies of cognitive reserve, mainly premorbid IQ, rather than the CRIq.
